HRT-1987-01 AN ARGUS SPECIALIST PUBLICATION
JANUARY 1987 £1.20
ALL NE
FT29
VFO ES El MI
ES ET1 ES ES El
-400°
ALL MOD
TRANSCEI
ALSO REVIEWED INSIDE: Sony ICF7600D Portable Receiver KW Corsair High Performance HF Rig Regency HX2000 Hand-held Scanner
cR. WITHERS COMMUNICATIONS LTD Manufacturers, importers and suppliers of world famous communications products
584 HAGLEY ROAD WEST OLDBURY, WARLEY, BIRMINGHAM B68 OBS
021-421 8201/2/3. CELLNET 0860 323056. PRESTEL MBX 214218216 FAX 0215614074 Amateur Radio. Business Radio. Radio Telephones. Sales. Service Accessories and antenna systems.
ICOM
R. WITHERS COMMUNICATIONS LTD
1111111illiEi
YAESU
THE TECHNICALLY ORIENTATED
1 THE MODERN
CONVENIENT WAY
RADIO COMMUNICATIONS
SPECIALISTS.
Please add £2.50 p&p for accessories, £5 for transceivers,
TO PURCHASE
Send £1.00 for Raycom catalogue (refundable) or send a large S.A.E. for latest used list and information.
* TOP TWENTY *
The following RWC Best -Sellers are normally Ex -stock at our Hagley Road Branch,
and are offered to privileged customers (subject to status) at these special rates. The RWC Card is available for most adult current bank account and creditcard holders. Your credit limit is 24 times your monthly payment. A 10% deposit is required on initial Instant Credit Purchases but existing RWC Creditcard holders need not pay a deposit. Once a RWC Cardholder you will be entitled to access the RWC CARDHOLDERS SPECIAL BARGAIN LIST. Please note that all Cash prices are
less than current list and in many cases are the lowest prices in the UK. (Prices correc at time of going to press. E&OE).
APPLY FOR YOUR CARD NOW. ** INSTANT CREDIT UP TO £1000.00 AVAILABLE TO LICENSED AMATEURS AND ENTHUSIASTS. APR 32.9%
YAESU MULTIMODE + HANDHELDS 3 YAESU FT29OR MULTIMODE 9 FT203R + FNB3 2MTR SUPER HANDHELD 4 FT209RH + FNB4 2MTR 5 Watts H/H
16 ALINCO ALM203E H/H C/W 30W AMP 19 FT709R + FNB3 70CMS KEYBOARD H/H
CASH PRICE £369.00 £255.00 £315.00 £239.00 £319.00
P/MONTH £14.00 £10.00 £12.00 £9.00 £12.00
YAESU AND ICOM MOBILES + DUAL BANDERS 7 FT2700R 25W 2+70CMS MOBILE 13 IC3200E 25W 2+70CMS MOBILE
20 IC290D 25W 2MTR MULTIMODE 2 NEW IC28E 25W FM MOBILE (RWC mod)
12 FT726 ALL MODE MULTI BAND V -UHF 17 IC271H 2MTR MULTIMODE 100 WATTS
£399.00 £499.00 £539.00 £349.00 £999.00 £989.00
£15.00 £20.00 £21.00 £14.00 £42.00 £38.00
YAESU AND ICOM HF MOBILE/FIXED 5 10735 ALL BAND 100W SUPER -RIG 6 FT757GX ALL BAND (C/W RWC mod)
15 IC745E ALL BAND HF TRANSCEIVER
£925.00 £949.00 £915.00
£34.00 £33.00 £37.00
RECEIVERS 11 FRG8800 ALL MODEL ALL BAND RX
1 FRG9600 MK2-RWC SCANNING V -UHF 14 ICOM ICR71 ALL MODE HF SUPER RX 10 ICOM ICR7000 25-1300MHz SCANNING RX 18 BEARCAT NEW 100XL H/HELD SCANNER
8 BEARCAT DX1000 SW 10-30MHz ALL MODE
£625.00 £499.00 £799.00 £925.00 £219.00 £329.00
£22.00 £18.00 £30.00 £35.00
£9.00 £13.00
THIS IS JUST A SMALL SELECTION OF THE STOCK WE HAVE AVAILABLE. AT RWC YOU WILL GET THAT BETTER DEAL. WE ALSO HAVE THE BEST UPDATED WEEKLY USED
LIST FULL OF BARGAINS ALL OF WHICH CARRY OUR FAMOUS THREE MONTH WARRANTY. Plus our VERY SPECIAL package Deals!
Please call us by telephone for a free brochure, Creditcard application leaflet or any other information. You may also order any of the above goods by AMERICAN EXPRESS, VISA, ACCESS, Diners Club on our 24hr answerphone. RWC Ltd are
licensed Credit Brokers. Full writen details on request.
OR POP INTO OUR HAGLEY RD. SHOP FOR A NO -OBLIGATION DEMONSTRATION OF ANY OF THE ABOVE
/ PRODUCTS. PLUS THE THOUSANDS OF OTHER LINES IN STOCK ... (Junc. 3 M5.)
DON'T FORGET!!! CHRISTMAS IS JUST AROUND THE CORNER, AND PRICES COULD GO UP AGAIN.
Tel: 021 421 8201 (24hr answerphone)
BARCLAYCARD
RI
f
Fa&drpil
Telex: 334303 G TXAGWM
EXPRESS DINE RS CI
IN If HNIAI IONA,
Consultant Editor Steve Ireland, G3ZZD
Editor Dave Bradshaw, G1 HRT
Assistant Editor Dave Bobbett, G4I RQ Advertisement Manager Dave Gadsden, G4NXV
Published by:
Argus Specialist Publications Ltd.,
1 Golden Square,
London W1 R 3AB
Telephone 01 437 0626
Distributed by:
SM Distribution Ltd.
Printed by:
The Garden City Press Ltd.
Design by:
IF
Argus Design Ltd. /LA&
ABC
VOLUME FIVE NO 1 JANUARY 1987
T
EGULAR COLUMNS
LETTERS
10
RADIO TODAY
12
Full details of the new all -British all -mode receiver - a Japanese beater?
TECHNOLOGY ROUNDUP
51
Crystals revealed
LISTENING ON
52
DXing on medium wave and tropical bands
RADIO TOMORROW
55
Update your diary here
2-80 TRANSVERTER
22
The cheap way to 80m - transmitter strip alignment
MORSE DECODER
28
Morse meets the micro with this cheap morse to centronics decoder
AUDIO CW FILTER
49
An AF alternative to costly crystals
Subscriptions: UK £17.30; o/seas sur £21; USA sur $28; o/seas air £39. Ham Radio Today, Subscrip-
tions Dept., Infonet Ltd Times
House, 179 The Marlowes, Hemel Hempstead, Herts HP1 1BB (tele: 0442 48432).
Ham Radio Today is normally published on the first Friday in the month preceding cover date. The contents of this publication including all articles, designs, Plans, drawings and programs and all copyright and other intellectual property rights therein belong to Argus Specialist Publications Limited. All rights conferred by the Law of Copyright and other intellectual property rights and by virtue of international copyright conventions are specifically reserved to Argus Specialist Publications Limited and any reproduction requires the prior written consent of the Company. (D 1987 Argus Specialist Publications Ltd. All reasonable care is taken in the preparation of the magazine contents, but the publishers cannot be held legally responsible for errors. Where mistakes do occur, a correction will normally be pullished as soon as possible afterwards. All prices and data contained in advertisements are accepted by us in good faith as
correct at the time of going to press. Neither the advertisers nor the publish-
ers can be held responsible, however, for any variations affecting price or availability which may occur after the publication has closed for press.
MAKE YOUR OWN PCBs
19
Doing it the professional way, with G3WPO
WHITE NOISE
42
A traditional Christmas ghost story, specially for radio clubs...
ATV PART 4
57
Get yourself on the telly with the final part of our series
.41Wil wit Alow
REGENCY SCANNER
15
The radio that reaches frequencies others cannot
SONY 7600D
24
Small box - big spec
NEW FT290
36
Not just a face-lift, but a brand new rig. Chris Lorek, G4HCL takes the covers off
KW CORSAIR
44
A CW buff's super -rig, emanating from the colonies
NEXT MONTH IN HAM RADIO TODAY
56
Free Readers' Ads
60
Classified Ads
64
Emporium Guide
65
Advertisers' Index
66
HAM RADIO TODAY JANUARY 1987
please mention HRT when replying to advertisements. 73 G4NXV
3
VHFIUHF FM
Handportables.
If you want a handheld with exceptional features, quality built to last and a wide variety of interchangeable accessories, take a look at the ICOM range of FM tranceivers. All ICOM handhelds come with an IC-BP3 nicad battery pack, flexible antenna, AC wall charger, belt clip, wrist strap and personal earpiece as standard.
,7-2ERIE, 2 metre and 70cm thumbwheel handportable. These popular handhelds from ICOM are still available. For those Amateurs who require a simple but effective FM transceiver the IC -2E and 4E take some beating. Frequency selection is by means of thumbwheel switches (with 5kHz up switch) and duplex or simplex facility. Power output is 1.5 watts or 150 milliwatts (2.5 watts possible with IC-BP5A batte pack).
-02E/04E 2 metre and 70cm keypad handportable.
These direct -entry CPU controlled handhelds utilize a 16 -button keypad allowing easy access to frequencies, memories and scanning. Ten memories store frequency and offset. Three scanning systems, priority, memory and programmable band scan, (the IC -02E now with an improved CPU retains duplex offset). These handhelds have an LCD readout indicating frequency, memory channel, signal strength, transmitter output and scanning functions. Power output is 3 watts or 0.5 watt in
low power position for the IC -02E and 2.5 watts or 0.5 watt for
the IC -04E. (5 watts is possible with the IC-BP7 battery pack or external 13.8V.DC.)
IC -12E 23cm Keypad Handportable.
The IC -12E has a 16 button Keypad allowing direct access to frequencies, scanning and memories. Ten memory channels store operating frequency as well as simplex/duplex and duplex offset. A priority function allows another frequency such as a repeater or calling frequency to be monitored. The IC -12E is equipped with a 1750Hz tone generator for repeater access. Frequency coverage 1260-1299.9875MHz with 5 frequency step rates. An internal power module provides 1 watt or low 100mW as standard.
' TELECOM
i* v. co
cran.,
toso, A4*
Also available for ICOM handhelds are a large range of
optional extras including a variety of rechargeable nicad power packs, dry -cell battery pack, desk charger, headset and boom mic, speaker mic, leatherette cases and mobile mounting brackets.
For more information on these handportables and other ICOM Amateur equipment contact your local authorised ICOM
dealer or Thanet Electronics Ltd.
0k
,
47 Cs
Seasons
ovreetings
tthoeICwOoMrldusoevresr
NEW! IC -MICRO TWO,
Mini-handportable.
This is the smallest handportable transceiver from ICOM. The MICRO -TWO, 2 metre FM measures only
148 x 61 x 31mm. with BP22 battery pack (not shown here). The MICRO -TWO is a hand -size transceiver which will equally fit most pockets.
Actual Size Photograph.
This shows the non-standard low capacity battery pack. N.B. Standard battery pack is normally the higher capacity BP22 as mentioned in text.
On the top panel a clear LCD readout gives frequency and memory channel number. Tuning is made easy using up/down toggle switches to select 1MHz,
100kHz or 12.5kHz steps as well as the 10 memory channels. Full repeater and reverse duplex operation facilities are featured including repeater access tone. An automatic power saving function reduces battery power consumption when in receive mode. Output power is 1 watt or 100 milliwatts (low) with the BP22 nicad pack.
The ICOM MICRO -TWO is the ultimate in 2 metre
miniature handheld transceivers, yet despite it's small size the receiver sensitivity and performance has not been compromised. This handy transceiver comes complete with the BP22 nicad pack (not shown here),
A.C. wall charger, helical antenna. Most existing ICOM accessories can also be used.
An optional extra, the BC50 desk charger will rapidly charge the BP22 battery in just one hour. Other
options include the BP23 long -life, low -power and BP24 medium -life, high -power nicad battery packs. Contact us
or your local ICOM dealer for more details on this exciting new product.
MICROWAVE MODULES LT
CONVERTERS
MMC50/28
6m down to 10m Converter
MMC144/28 2m down to 10m Converter
MMC432/28-S 70cm down to 10m Converter
MMC432/144-S 70cm down to 2m Converter
MMK1296/144 23cm down to 2m Converter
35.65 A 36.65 A 39.90 A 39.90 A 129.95 B
Just want to listen on a Band? See what it's like before you
buy one of our Transverters. Our converters are well proven, are excellent value for money and give reliable
service. A choice of popular 1.F's and inputs are available.
Designed to meet the most rigorous requirements the
new MMT144/28R and
MMT50/144 Transverters are guaranteed to give
satisfaction. Satellite
operation? Certainly our MMT432/28S is just what
you need. Perhaps the
challenge of 23cms appeals
to you. If so our MMT1296/ 144 will meet your require-
ments. Whatever your
needs be sure our Transverters are designed by
experts to the most de-
manding standards.
TRANSVERTERS
MMT432/28-S 70cm Linear
MMT1296/144-G 23cm Linear'
MMX1286/144 1268MHz Tra
MMT50/144
6m Linear Tn
MMT144/28
2m Linear Tn
MMT144/28-R 2m Linear Tn
WEATHER SATELLITE EC
70cms LINEAR AMPLIFIERS
MML432/30-L 70cm 30W Linear, 1 or 3W input MML432/50 70cm 50W Linear, 10W input MML432/100 70cm 100W Linear, 10W input
169.05 C 149.50 C 334.65 D
QRV on 70cms and need a
little more power? Our Linears provide the signal and quality you demand. The MML432/30LS has switched inputs for 1 or 3 watts (ideal for the FT708,
FT790R, etc). If you have a 10 watt TX and require a
modest output then the
MML432/50 will give you 50
watts. ORO? Our MML432/ 100 is just what the doctor ordered. Running a pair of
devices in the output a cool
100 watts is delivered to your aerial system. The 30 and 50 watt Linears both have receive pre -amps
fitted.
Our METROSAT equipment i; professinal market but we k friends have bought this super receiving signals from both the
the 1691 MHz band (METRO
lites around 137.00MHz (NOA, seen other systems demonstr and seen the best.
AMATEUR TELEVISION
MMC435/600 70cm ATV Converter, UHF output
MTV435
70cm ATV 20W Transmitter
Join the growing number of ATV enthusiasts. Our MTV
435 will give a full 20 watts peak signal. It has two inputs and an inbuilt test generator. To complement
this our MMC435/600 gives
you amateur TV signals on any domestic UHF TV. It all 35.65 A helps to keep you in the 197.80 B picture.
RF PREAMPLIFIERS
MMG144V 2m RF Switched GaAs MMG129623cm GaAsFET Preamr MMG16911690MHz GaAsFET Pre
Feedback is always necessary to stay on top if you have any problems or ideas please speak to our reps at any of the rallies or even one of our retail outlets. Club Lectures: Sorry if we haven't been able to answer all the mail or visit all the clubs. The response has been overwhelming. Hope to see some more next year. Best 73's Mick.
6
BUY THE BEST. A GOOD DI REMEMBER OUR PRC
Postage/Packing Charges: A = £1.84 B = £3.91 C =
VISA
MICROWAV
BROOKFIELD DRIVE, AINTRE
Telephone: 051-523 401 CALLERS ARE WELCOME
HAM RADIO TODAY JANUARY 1987
A SELECTION OF OUR PRODUCT RANGE FOR THE CONNOISSEURS OF AMATEUR RADIO
ransverter ransverter nsmit Up -Converter nsverter, 20W o/p nsverter, lOW o/p nsverter, 25W o/p
195.50 B 258.78 D 195.50 D 245.00 B 129.95 B 236.90 B
UIPMENT
PRICES ANTENAA 1691 MHz. GAASFET PREAMP 1691-1375 CONVERTER 137MHz
RECEIVER FRAME STORE 14" COLOUR MONITOR 137MHz AERIAL 137MHz PREAMP
333.50
129.95 145.00 424.35 906.50 286.35
69.00 46.00
designed and built for the now a lot of our amateur b equipment. Its capable of
geostationary satellites on AT), and the orbiting satel-
series, etc). You may have ated at rallies - now come
MICROPROCESSOR PRODUCTS
Learning C.W.? The MMS1 will help to achieve the pass slip you require. It sends letter, numbers or both, in groups of 1, 5 or 50 characters. Use the MMS2, and a key and it will even tell you
what you've sent! RTTY
enthusiasts will love the MM2001. It gives the full range of 45.5, 50, 75, 100
baud ASCII rates and will also provide 110, 300, 1200 baud ASCII range for computer systems. It plugs straight into your UHF TV
and gives superb results.
THE MORSE TALKER
MM2001
RTTY to TV Converter
MM4001-KB RTTY Transceiver with keyboard
MMS1
The Morsetalker
MMS2
Advanced Morse Trainer
MMS 1
189.00 B 299.00 D 115.00 B 169.00 B
Two meters must be the most 2 METER LINEAR AMPLIFIERS
popular VHF allocation to
UK amateurs and to meet
their requirements we pro-
duce a full range of linears
giving 30, 50, 100 and 200
watts output. Input powers
are 1 or 3 watts for the 30
watt linear, 10 watts for the
50 watts, 1, 3, 10 or 25 for the
100 watt range and 10 or 25 for the 200 watt unit. All of
our two meter linears are fitted with RF receive
MML144/30-LS 2m 30W Linear, 1 or 3W input MML144/50-S 2m 50W Linear, 10W input MLL144/100-S 2m 100W Linear, 10W input MML144/100-HS 2m 100W Linear, 25W input
MML144/100-LS 2m 100W Linear, 1 or 3W input
preamps.
MML144/200-S 2m 200W Linear, 3. 10, 25W input
94.30 B 106.95 B 149.95 C 159.85 C 169.95 C 334.65 D
All of our Transverters and some Linears come supplied with attenuators where needed. However, they are sold as a separate item, so if you need a 3, 7 or 10dB attenuator and just give us a ring.
ATTENUATORS
;FET Preamp )Iifier
amp
37.90 75.00 129.95
Are you unable to hear
all that's going on? Perhaps you feel that
your receiver is just a bit 'Deaf'. One of our preamps will soon
make amends. The two meter version is RF
switched and allows you to run 100 watts
through.
=AL ALWAYS MAKES SENSE.
)DUCTS ARE BRITISH
£4.60 D = £5.98
ALL PRICES INCL VAT 15%
MODULES Ltd
, LIVERPOOL L9 7AN, ENGLAND 1. Telex. 628608 MICRO G
PLEASE TELEPHONE FIRST
HOURS:
MONDAY -FRIDAY
9-12.30, 14.00 E & 0.E
HAM RADIO TODAY JANUARY 1987
MMR3/25 3dB 25 Watt Attenuator MMR7/3 7dB 3 Watt Attenuator MMR15/10 15dB 10 Watt Attenuator
19.95 A 14.50 A 14.50 A
CALL US NOW FOR DETAILS OF ABOVE.
7
IF YOU BUY a kit or module from us the chances are it will be from the top best sellers listed below. We are pleased to say that they just sell and sell and sell...
Shouldn't you have at least one in your shack?
70cms Modules
Assembled Kit
70FM05T4
500mW NBFM Transmitter 63.40 39.85
70FM05R5 70FM10 70LIN3/LT
NBFM Receiver 10W Power Amplifier 500mW Linear Amplifier
75.40 56.45 39.90
59.95 45.50 30.55
70PA2/S
RE Switched Pre -Amplifier 30.56 19.10
70PA5
GaAS FET Pre -Amplifier
23.60 14.75
TVUP2
70cms TV Converter
38.40 28.75
TVM1
70cms TV Modulator
11.60 7.25
24cms Modules
Assembled Kit
1250DC50
TV Down Converter
79.95
1250PA2
TV Pre -Amplifier
49.95
1240 TVT
Frequency Locked T'mitter 145.00
UFM01 VIDIF
420 MHz FMTV Exciter
41.25 28.25
IF Processor/Demodulator 63.75
SCT-2
Transmit Sound Modulator 16.50
SCR -2
Receive Sound De-M'Iator 24.95
VDBP1
Pre-Emp/De-Emp Module 10.50
2M Modules
144PA4
2M MOSFET Pre -Amplifier
144PA4/S
RF Switch Pre -Amplifier
144LIN25B RF Switched 25W Linear
17.20 31.20 49.20
10.75 19.50 35.75
General Accessories
TB2
Toneburst
7.50
4.70
PT3
Piptone
8.45
5.10
MPA2
Microphone Pre -Amplifier 6.25 4.60
All prices include VAT but please add £1.00 for postage and handling. Delivery is usually from stock or within 28 days.
A copy of our full list of modules and kits for practising amateurs is available for the cost of an A4 size SAE
Unit 12-13 Youngs Industrial Estate
Aldermaston, Reading
Berkshire RG7 4PQ Telephone: (07356) 71444
Telex: 846630
Access
WOOD Et DOUGLAS
VISA
VHF/UHF COMMUNICATIONS PRODUCTS
11 ,...411
NEW FROM SONY
AIR -7 MONITOR
AM 150KHz-2194KHz AM 108-136MHz WFM 76-108MHz NFM 144-174MHz
The new Sony Air7 is a superb new monitor having features so tar unmatched in a single hand-held monitor by any other manufacturer Its frequency coverage makes it deal for airband, public service or marine band monitoring, plus normal domestic use Highly sensitive, this receiver does everything you could ever desire in one package. The LCD digital display means clear frequency display even under bright illumination and the PLL circuitry ensures drift free reception Frequency is selected by keypad entry or electronic tuning and there is provision for disabling the keyboard 10 memories are provided for each of the 4 main ranges 110 in totall and comprehensive scanning is provided in the bands 106-170mHz Either full band or memory scanning is possible at a rapid rate Additionally, delays may be programmed into each memory channel, certain channels only may be scanned and any channel can be designated the TpnonN" channel. Accessories include BNC helical, battery cartridge shoulder strap etc. Options available - rechargeable battery cartridge 15.95; Mains PSU'
charger C13
PLEASE NOTE, unlike some versions on the market, these are not "grey imports" and therefore have both the full frequency coverage and the backing of SONY UK. No other amateur radio dealer in the UK can offer you this guarantee. Be warned,
SONY 2001D + AIRBAND OPTION & AC PSU!
Angus Mckenzie in Amateur Radio Magazine says "probably represents the best portable radio that one can get" and "far superior to anything that I have tried We can only agree with his comments It is a truly superb communications receiver that is completely portable covering 015-30mM/, Ph108mHzONFMI plus 116-136mHz AM air band. We can only touch on the features here such as Synchronous detector on AM for reduced interference, Switchable USB/LSB with separate filter, 55mHz first IF for good image response, both electronic and manual tuning the lamer with dual speed. signal metering, RF gain control, 32 programmable memones with scanning, search facility, 4 event timer, 24/12 hour clock, LCD readouts, mains power supply included. etc etc We have used this radio extensively on the office desk and it is a delight to be able to listen to the 00 on 11mHz, the natters on 3 5mzHz and the latest news from Radio Australia For home use an external aerial socket is provided and under these conditions it compares well with even the most exotic receivers. In stock now,
ALSO IN STOCK A.N-1 ACTIVE AERIAL KIT £49.00
CARRIAGE ON ALL ABOVE £2.50
JUST PUBLISHED 26-2250MHz No -Gaps!
THE COMPLETE VHF/UHF THE COMPLETE VHF/UHF
FREQUENCY GUIDE
* MARINE CHANNELS
FREQUENCY GUIDE
* CIVIL & MILITARY AIR
* POLICE, FIRE, AMBULANCE
* SPACE VEHICLES
* HAM RADIO REPEATERS
* UHF TV CHANNELS * FULL DUPLEX DETAILS
£4.95
* PMR
p&p 70p
* RADIOPHONES
At last the only "COMPLETE" vhf/uhf frequency guide available to the UK radio
enthusiast. Not just a collection of random frequencies put togethe in haphazard
fashion but a professionally prepared and printed guide based on he very latest
information available. 64 pages packed with a mass of information about this
fascinating part of the frequency range. Whatever you want to know, if its
between 26 and 2250mHz this guide will quickly take you to it. In fact it would be
difficult to imagine any enthusiast not having a copy of this beside him! The book
very clearly lays out comprehensive details of all the services that use this part of
the radio spectrum with their allocations and where applicable the separate
mobile and base station frequencies. It would be impossible to list everything that
this publication covers but it includes the following:- All UK marine frequencies
with coast station listings; civil airport and ATC frequencies; Military air including
air to air and air to ground including Red Arrows; Police; Fire and Ambulance
mobiles and base with duplex cross references; NASA voice channels; Russian
Space spot frequencies; Weather satellites, PMR; Outside broadcast channels
BBC/ITA; 2m and 70cm repeater listings; UHF TV channels; BT radiophones; new
band 3 PMR allocations and much more. There is no gaps (like some publications that have attempted to copy us and then got it wrong!); every part of the
spectrum is accounted for. No radio shack is complete without this invaluable
guide. Send or phone today for your copy.
- OTHER TITLES -
VHF/UHF AIRBAND FREQUENCY UST OCEANIC HF AIRBAND SUPPLEMENT WORLD RADIO TELETYPE HF FREQUENCY LIST
AIR TRAFFIC CONTROL
AIRBAND RADIO HANDBOOK WORLD RADIO AND TV HANDBOOK SHORTWAVE BROADCASTING GUIDE (times & frequencies)
0.95
£2.95
£3.95 £6.99 £4.99 £17.95 £4.95
ATE S
TANTON
RETAIL & MAIL ORDER:- 18-20, Main Road, Hockley, Essex SS5 4QS Tel. (0702) 206835, 204965
RETAIL ONLY 12, North Street, Hornchurch, Essex RM11 1QX. Tel (04024) 204965
Visa and Access by telephone. 24 hour securicor £6.50 extra.
8
HAM RADIO TODAY JANUARY 1987
TRIO KENWOOD 111751E
£525
ICOM R7000 25MHZ-2000MHZ
YAESU FT 290 MKII
A NEW VERSION OF THIS POPULAR PORTABLE
FRG moo £429
THE LONDON AMATEUR EMPORIUM
FOR EVERYTHING RADIO
TRIO KENWOOD
TS440
HF INC AUTO ATU
!CUE/H.1CW
0111.1111111M
£1050
VERY LATEST MINI -MOBILE 25/45 watts. RX 138-174MHz
£££ unbelievable value.
TRIO KENWOOD
TS940S
INC AUTO ATU
COMPLETE WITH FREE ARA 500 ACTIVE ANTENNA WORTH £129.00
£959
SONY ICF 76000
76-106MHz 162kHz-29995MHz MEMORIES, FM, AM, SSB.
SONY ICF 200ID
76-106 MHz 116-136 AIRBAND 160KHz-29995MHz FM - AM - SSB 32 MEMORIES INC PSU
FULL HF GENERAL COVERAGE TRANSCEIVER
+ 6M-2M+70cm £1395
SONY AIR 7
PORTABLE -AM -FM 144-174MHz 108-136MHz 150KHz-2194KHz
L
11
£1925 ALSO AVAILABLE
TL922 LINEAR INC TUBES £1225'
TRIO KENWOOD TS780
70cm-2 metres
Bressler
FOR TRW/KENWOOD
£950
ACTIVE ANTENNAS
A MUST FOR ALL SERIOUS SWLS dressier - ara 30 active antenna
200 kHz . . . 40 MHz
Professional electronic circuitry with very wide dynamic range. Meets professional demands both in electronics and mechanical ruggedness. .. 120 cm long glass fibre rod. Circuit is built into waterproof 2,5 mm thick aluminium tube. Ideal for commercial and swl-receiving systems.2120.00
D200 2 MTR 500W SSB
£858
D200S 2 MTR 750W SSB D70 70 CMS 550W SSB
£1018 £1030
- PRE -AMPS NEW MODELS
MODEL
FREQ.
NE
AIN
P 1 VVER
PRI E
NOW A NEW LOWER PRICE DRESSLER
ARA 500 ACTIVE ANTENNA
50MHz to 1300MHz Gain 17dB Typical TECHNICAL SPECIFICATIONS
FOR ARA 500
EW1296C EVV700 SMD EW200FB EVV2000GAAS EV2GAAS
1.25-1.3GHz 430-440MHz 144-146 144-146 144-146
0.9-1.2 0.5-0.9 0.6-0.9 0.6-0.8 0.6-0.9
16-18dB 100W 15-18dB 500W PEP 16-18dB 700W PEP 16-18dB 1KW PEP 15-18dB 100W PEP
£154 £117 £95 £105
£75
Gain
17dB Typical (14-17dB)
W INTERFACE FOR ABOVE PRE -AMPS
£31
Frequency Range 50-1300MHz
Noise Figure
1dB at 50-180MHz
15dB below 300MHz
2.0dB below 350MHz
2.7dB below 400MHz
3.0dB below 500MHz
3.8dB below 650MHz
£129.00
Operation is possible up to 1300MHz
with gain of 10dB
Noise
4-6dB
Intercept Point 3rd Order: +18dbm at Input
RECEIVE PRE -AMPS
MODEL
FREQUENCY
NOISE
GAIN
EWPA 560
50-600-1GHz
16.5dB-1dB
EWPA 560 (N) 50- 600- 1 GHz
1 6.5dB-1dB
IP3 order
+18dBM
17-18dB
ERPA 1296
1.25-1.30
0.8
15-18dB
ERPA 435
430-440
0.5
16-18dB
ERPA 144
144-146
0.7
PRICE
£79 £89
£114 £65 £60
OPEN: MON -
SAT 9AM - 5.30PM
INTEREST FREE
HP FACILITIES AVAILABLE
ON MANY ITEMS PROMPT MAIL ORDER
BARCLAYCARD
IMMO.
ASA 12
191 FRANCIS ROAD LEYTON E10
TEL. 01-558 0854 / 01-556 1415
TELEX 8953609 LEXTON G
0-IGHz
Masthead Antenna switch £59
dress er
HAM RADIO TODAY JANUARY 1987
9
1
RSGB - wrong
Dear HRT, Why do those who support the RSGB right or wrong, in reply to criticism of it, direct their comments not at the issues raised but at the individuals raising them. Is it that they are unable to respond to the issues?
We do need a strong RSGB but it must be 'open, 'responsible', democratic and 'accountable'.
At present the RSGB is none of
these.
Ian Abel, G3ZHI
. . . and right?
Dear HRT, Mr Ian Abel is of course fully entitled to air his opinions, but I feel that he has not given much time for the changes he wants to take place, either because of, or despite, his membership of RSGB.
He is however going too far when he mentions an RSGB staff who was presumably only carrying out her employers' instructions and who cannot reply, even if she wished to demean herself to do so. It is the lowest form of journalism to introduce personalities into the discussion, and I am surprised you published same, although you did add a postscript of your own.
As Ian probably knows only too well Ms Norman has been a loyal Society worker, for many years, and quite likely knows more about Amateur Radio than he does. She is not licensed, but the possession of a callsign does not mean that one is the fount of all knowledge, as Ian ably proves each time he applies ink to
paper.
I am delighted to learn that he intends resigning, then the time at the AGM can be spent on issues vital to our hobby like Interference and Planning Permission, rather than childish political squabbles about who wears the President's chain of office, and whether the elected Council should make decisions without canvassing members on each
occasion. Your other correspondent in the
December issue, Mr. Dick, is good enough to half -admit his mental state. He is dissatisfied over lack of attention by the RSGB to certain
views of his, but does not consider it relevant to let us know what they are, so we can decide who is being unreasonable. Having dismissed much of the contents of 'Radcom' as trivia, he has the cheek to suggest that failure to print his pearls of wisdom indicates a paranoid state of mind!
I have for some time considered that quality is more important than quantity, and feel that the RSGB in particular, and Amateur Radio in general, would be well rid of gentlemen such as this. They are welcome to form their 'liberal amateur radio society', whatever that means. They never tell us what the consititution of same would be, or what their intentions would be vis-avis the licensing authority.
They would however do well to do some thinking before they expect to
be taken too seriously. Just a couple
of points - although anyone can
contact his MP or a government Department, before they could claim credibility they would have to provide proof of how many amateurs they claim to represent. Also, they could not enter international contests or exchange QSL cards with bureaux worldwide, until such time as they were recognised by the IARU. These are the people who set themselves up as experts without any real in-depth knowledge, and it is rather laughable. I, and I feel most amateurs of any real responsibility, would much sooner leave the future of our hobby in the hands of the RSGB, despite its few warts, rather than a few malcontents who seem incapable of seeing beyond their own personal grievances and petty jealousies.
R G Sewell
Just like everybody else, both the RSGB and Ms Norman, are always welcome to air their views here in the letters page - however at the time of writing no such letter has been received.
As for the comment concerning introducing personalities into a discussion, it seems to me that if there were no personalities then there would be no discussion - hence the two are interconnected. It is far more dangerous for any organisation to
place itself above criticism than to participate in a discussion - which is why we publish letters which are critical of us here at HRT.
Asst Ed, G4IRQ
Kits and bits
Dear HRT, Thank you for your letter of 15th October relating to my inability to obtain a BF245 FET.
As regards your policy on 'single source' projects many of my friends and readers of Argus Specialist Publications feel that this policy smacks of pure commercialism.
As you are no doubt aware many Hams have quite a collection of components and can usually make up most projects without extra purchases except for one or two items and these are usually available (without postage) from local suppliers.
It is against all traditions of project building over the years in Amateur Radio to be so restricted and I think you will find that this deters 'would be' buyers of your mag.
Mr G Henshall, Liverpool
Unfortunately this is a 'heads I win, tails you lose' situation for us.
If we publish a project with no kit option then many readers are stumped because either they don't have access to PCB -making equipment or there are few (if any) component shops in their area. When we do decide upon a kit (and it is just an option, nobody is compelled to buy it!) then we find that somebody, somewhere will have local supply problems if they go it alone. As for the approach 'smacking of pure commercialism' I would point out that no supplier does it for free, whether it is a kit manufacturer or the shop 'round the corner. We would welcome comments from our readers on this topic - would you prefer to have the option of a project kit, or not?
Asst Ed, G4IRQ
QSL-ing with C5 - The
Gambia
Dear HRT, The RSTG regularly receives large numbers of QSL-cards
10
please mention HRT when replying to advertisements. 73 G4NXV
HAM RADIO TODAY JANUARY 1987
[iv-
11b
iit .cGz)
1
/14W/ -CciAsNCNc(a/,i
, 7(1\
-71-
- CQ RAZ
THE LAST
7
oR ..cg c Q.
CQ CQ " CONTACT /./ TIME .... ,/ ANY STATIONS
CALLING
tqt - ca - Cp.
APPREcIATEA fi/ife STK!' I 0 N
1 z---
ErOIN6-
_Is--- Q.RT
PLEASE REPLY-
csl..
/ 111;44 ) - ii(4
Ike
%._ M
/r(
A
7
cr (
r
,b de
a a ;-,--' DASH! fREQueicy is IN ()SE!!
,'-
come ON.-
.. HURRY IT UP :
' .01'
AI -4. Goof). AT LAsr. FREQUVIO/ CLEAR
«t '
4 (( - d
S
Aga& ,,
(
VI oertFR
Wirtie
for C5 calls, which for the one or other reason cannot be processed.
Most of the active hams here are expatriates, who come to The Gambia on short-term contracts rarely exceeding two years.
Cards sent "via the bureau" are normally forwarded by sea mail and may take a year or more to reach The Gambia. The risk that your QSLpartner has meanwhile left the country is therefore considerable.
The following suggestions may assist in obtaining confirmation of a C5 contact. 1. QSL only directly and by air mail 2. enclose a self-addressed envelope and 2 IRCs 3. check the validity of the C5 call worked in the latest International Call Book, it seems that the C5 prefix is a favourite with pirates.
All QSL cards received by the Radio Society of The Gambia will be distributed promptly to such members who either still are in The Gambia or whose forwarding address is known. All other cards can be returned only if return airmail postage (two IRCs) has been enclosed - there is no outgoing seamail from here, so cards will have to be returned by air.
The address of the RSTG is: Radio Society Of The Gambia, P.O. Box 2470, Serrekunda, via Banjul, The Gambia, West Africa.
Juergen Rosenstock C53CR
Do you know Goliath?
Dear HRT, I am engaged on a programme of research into a Very Low Frequency, transmitting radio station established in Germany late autumn 1941.
The station called "Goliath", was near the village of Kalbe (Saxony, Prussia) and partially straddled the River Milde.
I seek any information, no matter how small or seemingly trivial. Any drawings, photographs, technical details or personal memories by German or Allied personnel would be especially welcome. Any documents loaned to me would be treated with care and postage refunded.
My address is: Mr T F Bernacone (GOLIATH RESEARCH PROJECT) Teesside Polytechnic Borough Road Middlesbrough Cleveland TS1 3BA
T F Bernascone
TO: 'DISILLUSIONED G1', MANCHESTER
Your letter came as no surprise to me, my young friend - there will always be those who decry 'youth' - it may be that they feel superior having gone further in the process of natural decay or (more likely!) that they are jealous of your early prowess! I would suggest that you take no notice of them, neither derogatory remarks or evil 'jamming' activities - such tiny minds have little persistence, especially if no notice is taken of their behaviour! You, of course, don't have to listen to, or work them!!
Having encouraged and trained a vast number of young amateurs into the fraternity, might I suggest that you review your own operating procedures with a view to removing any grounds for their comment?
It isn't a particularly good point to stress your age (proud though you may be to have achieved a licence at a relatively early age!) leave the matter until you meet fellow Hams at club or social events, and at such take up the attitude of being 'all ears' on discussions and talks, there will be many future years when wider horizons may enable you to make comment and suggestions which will,
then, prove most acceptable! The great majority of amateurs you will find are keen to help the beginner and will always behave with courtesy and consideration towards others who manifest the true 'Ham Spirit'.
You are quite wrong to go QRT! giving into the offending types is no way to meet their 'tiny -mindedness' - get on the air, ignore their efforts, and QSO anyone who you can raise! I am sure you will find your detractors only represent a lunatic fringe and are not remotely symptomatic of the amateur fraternity as a whole!
In case you wonder at my grounds for writing this, I would explain that I have been in Amateur Radio for 70 years having built my first receiver at the age of 8! - the true OT would never behave as those you mention appear to do!
73 - keep your chin up.
Brian Herbert, G2WI
Ageist? Not us
Dear HRT, After reading the letter in November's HRT I felt I must write and say that by no means are all Amateurs ageist. I am now 17 and have been licenced since I was 15, and have had nothing but help and encouragement from all the local amateurs.
I do believe that it is in many ways harder for young amateurs to get on the air because of financial and many other reasons.
I hope that the 'disillusioned G1' will be able to continue with his hobby and have as much enjoyment in the future as I have had over the last two years.
If any other young amateurs would like to write to me I would be pleased to try and set up some link between young amateurs around the country.
Nigel Knapton, G1IKE
HAM RADIO TODAY JANUARY 1987
please mention HRT when replying to advertisements. 73G4NXV
11
23.586
The Matlock Mole does it again!
As you can see from the photo, we have been able to obtain much fuller information on the forthcoming Lowe Electronics
HF receiver which we brought to your attention last month. The new receiver, called the HF-125, offers continuous
coverage from 30kHz to 30MHz, on AM, USB, LSB and CW and sports a variety of filters even in the standard package - which is expected to sell for something in the region of £350. A 2.5kHz filter is used for SSB and there is a 400Hz audio filter for CW buffs. For normal AM reception you can select a 4, 7 or 10kHz filter to suit the conditions, with the
rig automatically selecting the appropriate filter for you when you change mode. So the 2.5kHz filter is selected on SSB and the 7kHz filter is initially switched in for AM, although
the user can 'interrogate' the rig to see which filter is in use and change to one of the others if desired.
Frequency readout is by means of an LCD (which also serves to show which filter is in use) displaying the VFO frequency in normal use or the contents of the 30 memory channels available. Initial selection of the MHz range required is by means of two Up/Down buttons with a conventional tuning knob acting as the 'fine tune' facility. The tuning knob is a good bit more 'intelligent' than this though, the stepping
rate being matched to the mode in use (15.6Hz per step on SSB/CW for example), and the stepping increment being increased as the rate of knob rotation rises - so there is no need to get out an electric drill to wind from one end of the band to the other.
Other features include a noise blanker, an RF attenuator, tone control and an overall size of 255(W) x 100(H) x 200(D) mm which is roughly 10x4x73/4 inches. Options available for the standard rig consist of the D-125 combined FM and synchronous AM detector boards, P-125 Nicad & charger pack with active aerial and the K-125 'Genie' keypad frequency controller.
Further details (which we must point out are provisional at this early stage) are shown in the table.
HF-125 Receiver -Provisional Specification
Frequency coverage 30kHz to 30MHz continuous coverage. Detection modes.... AM
SSB (USB, LSB and CW).
Tuning
FM and Synchronous AM (optional). By spin -wheel, continuous tuning in 15.6Hz
steps. Step size increases with faster tuning
rate. Megahertz quick selection by up/down
Memories
push buttons. Keypad frequency entry (optional). 30 frequency memories with lithium battery
back-up for approx. 10 years. Filter bandwidths 2.5kHz, 4kHz, 7kHz, 10kHz. 400Hz audio
filter for CW.
Sensitivity
SSB mode: 0.3uV for 10dB SIN. AM mode:
0.7uv for 10dB S/N (0 70% mod. (Typical
RF attenuator Noise blanker
Tone control
values for frequencies above 500kHz). User selectable 20dB attenuator. Permanent operation. 0.4ms blank period. Flat response at mid -point, with progressive
Dynamic range
HF roll -off at clockwise rotation and LF roll off at anticlockwise rotation.
Greater than 90dB at 50kHz from tuned
frequency (both inter -modulation distortion
Image/spurious responses Audio output
and reciprocal mixing).
Greater than 80dB rejection. 0.75W into internal loudspeaker. 1.25W into
external 4ohm loudspeaker.
Connections
Aerial input: 50ohm via SO -239 socket.
600ohm + Gnd terminal.
Active whip aerial (optional).
External loudspeaker output..3.5mm jack.
Headphone output (100mV) 6mm jack.
Record output (100mV)
3.5mm jack.
Power supply
12V DC power input
2.1nun jack.
External 12V DC supply at approx 250mA.
AC mains adaptor supplied. Internal Nicad
batteries and charger to give around 10 hours
Options
operation (optional). FM and Synchronous AM modes (D-125).
Nicad pack, charger and active whip aerial
(P-125).
"Genie" keypad frequency controller
(K-125).
Size
Approx. 255x100x200mm (WxHxD).
HF -125 " I
ANTENNA 600. WOE COO NC
O0 0
. 504/TLCM RECORD
CET
POWER
LEVEL
OUT
L!
12VDC
12
please mention HRT when replying to advertisements. 73 G4NXV
HAM RADIO TODAY JANUARY 1987
The Leicester show More of a Radio Yesterday feature now I suppose, but we would like to say 'thank you' to all the readers who came to visit us at the HRT stand and made the exhibition such a success. Both the Friday and Saturday were very busy with
Friday's pre -opening queue stretching back for some consider-
able distance and, we suspect, consisting of quite a few people who wanted to avoid Saturday's rush! Nevertheless there was enough room for everyone. Chris Lorek, G4HCL, was there terrorising the assembled multitudes as he gave live colour Amateur TV demonstrations using the `HRT' ATV system
- so many visitors enquired whether it was 'real ATV' or `just video' that we decided to stick a callsign on the camera!
- Great fun was had by all - see you there next year? TODAY
,0 ..,
47 114,7:
-4111111111111111111
........-
1111.1011.11.
Fast fuse and socket tester
Galatrek of Llanwrst, North Wales have brought out a 13 amp socket tester for those of use who spend the occasional weekend rewiring the shack. It's about the same size as a normal plug and can test for six different mains fault conditions - the price is £1495 including p&p and VAT. Unfortunately the model Father Christmas in the photo is not included and we can only assume that the top of his head is missing because he didn't use one of Galatrek's mains testers! Further information on the socket tester (and presumably Father Christmas too) from: Galatrek International Ltd, Scotland Street, Llanwrst, Gwynedd, North Wales, LL26 OAL. Tel: (0492) 640311.
'I dunno how to plug it in either!' Chris Lorek and Ads
Manager Dave Gadsden grapple with leading edge technology.
AX25 Packet for 1200 Baud modem for use on
Dragon
VHF costs £99 and the soft-
ware can be supplied separ-
Grosvenor Software have ately for £49. An HF adaptor
launched a new packet pack- (essentially a filter unit) will
age for owners of Dragon also be available in the near
32/64 and Tandy Color com- future at around £30, all
puters. Developed by Mike prices being inclusive of p&p
Kerry, G4BMK, the system and VAT. We have been told
is a complete implementation that there is a BBC Micro
of version 2 of level 2 AX25, version on the drawing board
but is also capable of com- which should be available in
municating with stations two or three months time.
using the earlier version 1 Further details can be
implementation. The com- obtained by sending an SAE
plete package consisting of to: Grosvenor Software, 2
software in either disc or Beacon Street, Seaford, East
ROM cartridge form, plus a Sussex, BN25 2JZ.
New Greenweld cat
Seems to be the time of year for new catalogues as the winter building season comes
upon us. The latest one is from
Greenweld of Southampton whose 1987 edition contains nine pages of bargain buys, a draw for a three day holiday and about 80 pages of electronic goodies for the enthusiast ranging from cornponents to computer accessories. Available from Green weld Ltd, 443 Millbrook
Road, Southampton, SOl OHX for £1 including postage.
NTS FROM ONE SOURCE ALL TOUR COMRON
1987 cATALOGUE
.,,,
a taw °,,`It'' mow et
Naha.
.
High power variables
Another seasonal touch comes from Telecomms of
Portsmouth in the shape of these elegant toast racks, which cunningly double as QRO variable capacitors. The TC-250 has a range of 13 to 250pF whilst its bigger twin-gang relative (the TC-500) covers the same range on each section. Both versions use 2mm air gaps which gives them a breakdown voltage of 7.8kV. The TC-250 costs £18.95 and the TC-500 is £22.42 - both prices include VAT. Further details from Telecomms, 189 London Road, Portsmouth, P02 9AE. Tel:
(0705) 698113.
Catch them young
Peter Beardow GLSHV, Communications Project Manager for the Virgin Atlantic Challenger II record speed run, casts a professional eye over two budding electronics engineers at the Surbiton District Scouts JOTA station GB2BG. Scouts visiting the JOTA station were invited to construct a simple device to obtain a credit towards qualifying for an Electronics badge. The kits of parts for the project were provided by the Wimbledon and District Radio Society.
[>
HAM RADIO TODAY JANUARY 1987
please mention HRT when replying to advertisements. 73G4NXV
13
Babani book bank
Well an index really! If you are interested in things technical then you will no doubt also be interested to learn that Babani Ltd will be happy to send you a copy of
their latest technical book list free, gratis and for nothing! Their address is Bernard Babani (pub-
lishing) Ltd, The Grampians, Shepherds Bush Road, London W6 7NF. If you really can't wait then you could phone them on
01-603-2581 or 01-603-7296.
Sorry about the misprunt!
It looks as though the brain and the fingers weren't con-
nected up properly again last month. We gave the wrong phone number for Techni-
bond Ltd in the 'Making Your Own PCB's' article.
The correct number is (0494) 448791 and not as shown in the article - our apologies to
the owner of the number
which we published, namely
Queen Hithe Press of Kings Square, High Wycombe.
WASR Award
Society, GM3BSQ, may be sub-
If you've been roamin' in the stituted for any one region.
Gloamin airwave, or taking the
If you think you qualify, send
high and the low ether roads, why a list of claimed regions and
not apply for the 'Worked All contact details, countersigned by
Scottish Regions' award? As you'd a radio club secretary or chair-
imagine, you'll have to be able to person, to GM4BKV, S. Suther-
show proof that you've had two- land, 67 Greenfern Road,
way contact with at least one Mastrick, Aberdeen AB2 6TP.
station in each of the Scottish The cost of the award is UK £1 or
regions sometime since May 1st IRCs to that value.
1975. And if you're not too sure of Whilst we're on the topic of
the Scottish regions, here's a list: Aberdeen Amateur Radio Society,
Borders, Central, Dumfries & who administer the WASR Award,
Galloway, Fife, Grampian, they'd like us to mention that their
Highlands and Islands, Lothian, club meets are at 35 Thistle Lane,
Strathclyde and Tayside. Contact Aberdeen, at 7.30 pm every
with Aberdeen Amateur Radio Friday.
AKD Move House
AKD - the RFI filter
people, have now moved to new premises in Stevenage and have also introduced the first of a series of new products. The new HFC1 HF converter is designed to fit the FRG9600 super -scanner to give it coverage of 100kHz
up to 60MHz. Using a
double balanced mixer and low pass filter combination, the unit simply plugs directly into the aerial socket and a flying lead takes power from the rigs 8v supply connector. The remarkable thing about the unit is its size, measuring
only 90(L)x25(H)x25(VV)mm (that's 31/2x1x1 inches) - the price is £49 exactly and can
also be supplied with BNC
type connectors instead of the PL259/S0259 combin-
ation. Also from AKD comes
the offer of a free EMC help-
line service which is available
from 10am to 12 noon every weekday on their usual telephone number. AKD's address is: AKD, Unit 5, Parsons Green Estate, Boulton Road, Stevenage, Herts, SG1 4QG. Tel: (0438) 351710.
1B. N. O. S.
ELECTRONICS
1986 PRICE LIST
2M LINEARS
70CM LINEARS
POWER SUPPLIES
LP144-3-50 LP144-10-50
L144-1-100 L144-3-100 L144-10-100 L144-25-160 L144-3-180 L144-10-180
LPM144-1-100 LPM144-3-100 LPM144-10-100 LPM144-25-160 LPM144-3-180 LPM144-10-180
125.00 125.00
172.50 172.50 150.00 230.00 270.00 270.00
197.50 197.50 175.00 255.00 295.00 295.00
NEW LOW-PASS FILTERS
F50-UU F70-UU F144-UU F144 -UN F432 -UN
24.95
24.95 24.95 28.50 28.50
L432-1-50 L432-3-50 L132-10-50 L432-3-100 L432-10-100 L432-25-100 LPM432-1-50 LPM432-3-50 LPM432-10-50 LPM432-3-100 LPM432-10-100 LPM432-25-100
6M LINEARS
LP50-3-50 LP50-10-50 LPM50-10-100
4M LINEARS
LPM70-10-100
195.00 195.00 155.00 295.00 295.00 255.00 235.00 235.00 195.00 335.00 335.00 295.00
135.00 135.00 195.00
195.00
12/6A
69.00
12/12A
115.00
12/25A
169.00
12/40
345.00
NEW PROFESSIONAL VARIABLE
VOLTAGE MODELS AVAILABLE
NICADS
Format
AAA N'
1/3AA 1/2AA AA
AA (Super) AA*
1/2A*
RR C D (SUB)
D'
F PP3
Capacity
(Ah)
0.18 0.15 0.10 0.24 0.50 0.60 0.50 0.45 1.20 2.20 1.20 4.0 4.0
7.0
0.11
1-9 2.23 2.00 1.50 1.20 1.23 1.35 1.25 1.40 2.38 3.10 3.25 5.75 5.80 8.63 5.25
Price 10-24 25-49 2.12 2.01 1.90 1.81 1.43 1.35 1.14 1.08 1.17 1.11
1.28 1.22 1.19 1.13 1.33 1.26 2.26 2.15 2.95 2.80 3.09 2.93 5.46 5.19 5.51 5.23 8.20 7.79 4.99 4.74
Available direct or from all good radio dealers. SAE for more details.
N those Delivery Free (For orders over £10) under add £1 to order total Securicor 13' available at £5 extra
MI
DON'T FORGET OUR NEW ADDRESS BNOS ELECTRONICS LTD. DEPT PW, STEBBING, ESSEX CM6 3SL. Tel (037186) 681
14
please mention HRT when replying to advertisements. 73 G4NXV
HAM RADIO TODAY JANUARY 1987
Regency HX2000
gGGTDOD
LD
Man is a naturally curious animal.
Some may say the more intelligent
one is, the more curious one becomes, continually wanting to
something I could easily slip into my
inner jacket pocket. As the
staliholder was watching and I knew
I wouldn't get away with it,
Handheld scanners are a bit of a rarity; Chris Lorek, G4HCL, looks at one of the few to make it to our shops, and probably into a few Christmas
stockings.
know more and more. Others may say they are just rather nosey! All around us the airwaves are filled with radio signals, amateurs are well
aware of this of course, but
capturing those hidden messages still remains a wonderous pastime, especially finding radio channels with something 'different' from the 'run of the mill' going on. Is it any wonder that many radio amateurs dream of finding a scanner receiver in their Christmas stocking!
Handheld Scanners
There are several scanner
receivers on the market, the majority
of which are designed for a fixed installation, drawing power from an external source. Three popular models have been reviewed in the
Oct 86 edition of HRT, which all give a wide frequency coverage but still
tie you down to a base or mobile installation. Miniaturisation of circuitry is always on the increase, with the result that scanners have
been getting smaller and smaller, but
until the last few years handheld
scanners have been limited to crystal controlled operation of a few user fitted channels. The first synthesised
handheld scanners were big and
bulky, they certainly made a bulge in your pocket and weighed you down a bit into the bargain. Not the sort of thing you could carry around an air
show comfortably. When I first handled the Regency HX2000 scanner at the Woburn rally I knew that it was something different,
pleasantries were exchanged and a sample was instantly provided.
Features
The set measures a small
77mm(W) x 175mm(H) x 39mm(D),
and weighs 420g with nicads
installed. It comes in a smart twotone grey case which could easily be mistaken for one of the modern portable cellular phones at first glance. A detachable belt clip is fitted to the rear. The frequency coverage is 60-89MHz, 118174MHz, and 406-495MHz, this gives coverage of the 4m, 2m, and 70cm amateur bands as well as many other two-way commercial and aeronautical frequency bands.
Twenty memory channels are
provided, each capable of storing frequency and AM/FM mode.
Any number of memory channels may be scanned for activity, for instance you may scan channels 4-18 inclusive, 15-20, 1-8 and so on, but not individually selected channels. You may however lock out any channel within the programmed range, which gives far greater flexibility. Scanning stops when a signal is found and dependant upon the setting of a 'Hold/Delay' facility, either permanently halts the scan or resumes a few seconds after the signal disappears. A 'Priority Watch' samples channel 1 every few seconds, locking onto it if a signal is found.
Scanning between any two
programmed frequencies is possible
in 5kHz, 10kHz, and 12.5kHz steps, with AM or FM selectable on any range. When an active frequency is found, the scanner will lock onto it either permanently, or resume sca-
ning a few seconds after the signal disappears - again depending on the setting of the 'Hold/Delay' function. You may if you wish enter the newly -found active frequency into one of the memories simply by
pressing the 'Enter' button followed by the memory channel number.
The display is a large, liquid crystal affair, with a switchable backlight for night use. It displays the
frequency, AM/FM mode, memory
HAM RADIO TODAY JANUARY 1987
please mention HRT when replying to advertisements. 73G4NXV
15
1 VHF LO
-165
118-174
VHF HI
1 406-495
20.945MHz 21.4MHz
UHF
UHF
O VHF HI
LO
427.4 516.4
139.4-195.4
81.4- 10.4
MC3357 CFX455E
SQUELCH CONT.
FM_
0
SELECT
BA4210
SELECT
LM386 AF AMP
DUAL -MODULUS PRESCALER uPD571
KEYPAD
TUNING VOLTS
SYNTH uPD2833
REF OSC
CONTROLLER uPD7514
-t O VHF LO VHF HI
.-4*-0 UHF -10-0 FM
-0-0 AM
Schematic diagram of the HX2000
LCD
The Regency HX200 Scanner
sx,,i
" .>":"''
\\'':\s\
V" -
channel number, search, scan, and
hold or delay modes, frequency incremental step in use, channel lockout, and on top of that finds room for a low battery warning
message too. Slider controls are provided for
volume and squelch, 3.5mm sockets
are fitted on the top to allow
connection of an external aerial and earphone. 2.5mm jack sockets on the side allow in -situ nicad charging and for the connection of an external 6v power source (more about his later). The set comes provided with a flexible screw -on helical, four AA size nicads and mains charger, a protective case cover, plastic belt clip, earphone, and instruction booklet.
Initial Thoughts
Despite the smart looking case, it does still look a little 'plasticky' in
construction, but then any alternative would no doubt make it far heavier so maybe I'm being my
usual fussy self. The plastic belt clip I feel would not last too long, though
I resisted the temptation to perform
a destructive test on it! I would have
thought that a BNC would have been
a better choice for an aerial connector than the jack socket
fitted, expecially at UHF. However
this could allow a more convenient
changeover beween fixed and
portable operation, saving you trying
to find somewhere to store the
disconnected helical. I liked the clear LCD display, and the slider controls
also were easier to use than the fiddly little knobs so often seen on small handhelds nowadays. The protective case cover is made from
a strange rubbery fabric which does not look particularly smart, but would give the set far better drop
protection than the usual plastic
cases often supplied. The nicad charger is a two -pin
wall plug type power supply,
requiring a shaver adapter for use in this country. It provides 6V at up to
200mA into a 2.5mm jack plug,
could this be right! AA nicads require
only 45mA charging current. I also
had a few worries about the identical
external power connector. A circuit
16
please mention HRT when replying to advertisements. 73 G4NXV
HAM RADIO TODAY JANUARY 198 7
diagram (separately requested) of the scanner showed that a current limiting resistor is fitted in line to the nicads to protect against excessive current, but also showed that the external power socket was connected through a diode to the nicad terminals. this would mean that the nicads MUST be removed before connecting an external power source, although this was not made clear in the operating booklet. However as long as you remove the batteries, this facility enables the charger to double as a base supply.
In Use
Apart from the points regarding the nicad charging, I found the
scanner very easy to use, 'user friendly' I believe is the current hi tech phrase. For instance, to
manually enter 145.750MHz FM into channel 10, you press 'Manual' followed by 1 4 5. 7 5 0, a flashing
cursor prompts you for each
successive digit, then 'Enter', 'AM/FM' flashes asking you for the mode, and the cursor blinks next to 'CH' prompting you to enter 1 0 the desired memory channel number.
Similarly when searching for activity,
flashing prompts for frequency,
increment and search makes operation childs play. In fact, even the
editor G1HRT was using the set within seconds of grasping it from
my hands, it was quite a while before
I managed to retrieve it - clearly showing its addictiveness!
The set was very light, it could easily be carried around almost without knowing it was there. The earphone facility allowed me to wander around on shopping trips or whatever whilst quietly scanning
around, it certainly makes a change from personal stereo listening! The set seemed fairly sensitive, com-
paring reasonably with the average
2m or 70cm handheld. This did
sometimes create problems though,
on the lower frequencies around 70MHz there was an abundance of
urban man-made noise which invariably stopped the scan sequence.
Walking past the many computer stores here in Cambridge using the set showed this up very nicely, but
even when operating at home into an
external aerial I sometimes wished for a tighter maximum squelch setting. I also found a slowly varying instability on VHF as the batteries
started getting low which again was
a little annoying, but then I'm
starting to be very critical again. The loudspeaker volume was
just about sufficient for normal handheld use, but operating in a
noisy environment did require use of
LABORATORY RESULTS
Sensitivity/Image Rejection
Sensitivity measured as uV pd to give 12dB SINAD, FM 3kHz dev; AM 80% mod. Image rejection measured as dB increase in image frequency signal needed to give 12dB SINAD on tuned frequency.
Frequency
(MHz)
60 68 78 87.5 118
128
138 145 160 170 406 430 440 450 460 470 490 495
FM Sensitivity
(uV)
0.31
0.29 0.30 0.32 0.18 0.18 0.17 0.21
0.21 0.22 0.67
0.34 0.33 0.33 0.34 0.46 0.95 0.97
AM Sensitivity
(uV)
0.72 0.69 0.67 0.71 0.47 0.46 0.44 0.59 0.59 0.61 1.9 1.3 1.3 1.3 1.3
1.7
2.8 3.0
Image Rej. (dB) 12 17 25 26
9 9 9 9
23 32
0 6
7 6 5 5
2 2
the earphone. For mobile use, an external speaker with a built-in
amplifier such as the type obtainable for personal stereo home use would be needed.
When scanning the UHF ranges, I found a strange buzzing signal was received on some frequencies, this turned out to be image reception of UHF television signals, 42.8MFiz above the displayed frequency. Also when operating using an external
aerial from home, I occasionally suffered with cross modulation breakthrough from local military aircraft that come down to 100ft AGL, terrifying the neighbourhood kids.
These are of course local effects but
they show that every receiver designed to cover so many fre-
quencies in such a small size must suffer one or two compromises.
Inner Technicalities
No circuit information is pro-
vided with the set, so the technically inquisitive please read on, others feel free to ignore the following totally! Fig. 1 shows the inner workings in a G4HCL-generated block diagram form. Three voltage -controlled oscillators covering low VHF, high VHF and UHF are diode switched under microprocessor control to generate
21.4MHz above the desired frequency in each case. A uPD571C dual -modulus prescalar together with a uPC2833 synthesiser, divide the VCO signal to a fixed reference where they are phase compared
with the crystal -generated reference frequency. These NEC IC's together take only 18.6mA of current and pro-
vide a state of the art method of
generating a spurious -free oscillator signal, previous generations of UHF dual -modulus divider IC's have been very expensive and power hungry, rendering a mixer -type synthesiser (with its inherent spurii problems) necessary in the past.
One of the three varicap-tuned signal frequency amplifiers is also diode switched into circuit, which amplifies the receive signal frequency range and applies it to a bipolar transistor where it is mixed with the VCO signal. A monolithic dual crystal filter provides broad selectivity and the filtered signal is
then passed to MC3359 and
BA4210A ICs for FM and AM detection respectively, each having further
filtering incorporated in its own
HAM RADIO TODAY JANUARY 1987
please mention HRT when replying to advertisements. 73G4NXV
17
associated circuitry. The selected audio output is diode switched and applied to an LM386 audio amplifier.
An 80 -legged uPD7514 custom IC performs all the housekeeping and memory functions whilst memory backup uses a two -cell nicad, hence obviating the need for lithium battery replacement every few years.
Laboratory Results
A sensitivity check was first carried out and this confirmed the
excellent results obtained on the air. At 490MHz and above the performance starts to drop off a little but this of course is the UHF TV band in
this country and hence is of little relevance here. The FM adjacent channel selectivity was surprisingly good for such a set. This degraded a little on AM, due to bandpass
tuned circuits being used rather than a ceramic 455kHz filter, but it was
still far better than some of the popular handheld crystal airband
receivers for instance. The good blocking performance
surprised me, as did the high cross modulation rejection, showing my
AM military aircraft breakthrough
due to extreme proximity effects. What was a little disappoint -
Unwanted Signal Rejection
Rejection ratio of interfering signal, modulated 400Hz at 1.5kHz dev
Cross Modulation Rejection
(FM), 30% mod (AM), causing 6dB 145MHz FM from 350MHz AM 90dB
degradation of 12dB SINAI) on - 450MHz FM from 120MHz AM 94dB
channel signal.
Current Consumption
Adjacent Channel Selectivity
Scanning, no signal 73mA
FM + 12.5kHz 51dB
Receiving, mid volume 83.5mA
- 12.5kHz 33dB
Receiving, max volume 102mA
+ 25 kHz 62dB
+ 25 kHz 59dB
Maximum Audio Output
AM + 12.5kHz 36dB - 12.5kHz 17dB + 25 kHz 47dB - 25 kHz 41dB
FM, 5kHz deviation received signal,
AM 80% mod similar, (2.5kHz FM, 50% of quoted output); Into 3 ohm load: 27mW;
Blocking rejection
Into 8 ohm load: 40mW; Into 15 ohm load: 56mW.
FM 78MHz from 80MHz 70dB Increasing load resistance above
FM 145MHz from 150MHz 68dB, 15 ohms reduced output level.
ing however, was the image rejection, ie reception of signals at the
'other side' of the intermediate
frequency difference. This explains
the UHF TV breakthrough, but also
shows the general failing in many
scanner receivers in this respect. The
front end selectivity stages are varicap tuned to track the programmed frequency and a high IF
helps, but without the use of several stages of high -Q front end tuned
circuits or a UHF first IF, the problem
remains.
The battery consumption was higher than expected although this still allows around five and a half hours of use following a nicad charge. The low audio output confirmed the effect noted in everyday
use, this is probably due to the audio
IC operating from a much lower vol-
tage than it is capable of using. The low battery indicator, which in fact
coincides with the set being
rendered inoperative, occurs at
4.68V which gives little margin
when using four 1.2V nicad cells.
Conclusions
Designing a receiver such as this
must impose many performance
limitations, but I feel that the
HX 2000 exhibits a good compromise in many respects, yet with performance exceeding my expectations in others. Only the image rejection lets it down, but to
be fair this is a common failing with
many scanners, only the use of
circuitry requiring more current and more space would get over this. I
was pleased with the overall
performance and it certainly proved
its worth by the sheer fact of its versatility. It kept me happily
occupied on several business trips! My thanks go to Garex Elec-
tronics for the loan of the review set
at such short notice.
18
please mention HRT when replying to advertisements. 73 G4NXV
HAM RADIO TODAY JANUARY 1987
If you want to produce a professional
looking PCB, either because you feel
the need, or are going to produce lots
of boards, or even publish something, then you will be looking at
have photographic reduction facili-
ties to be able to produce the final boards. Hence you will normally work at 1:1 - personally I find it
much easier at actual size as you get
Thinking of getting professional help with your PCBs? Tony Bailey, G3WPO, shows the way.
using pre-cut symbols and tracks of some description that are later photographically transferred to the PCB. This does involve some, ex-
pense but the results are well worth
it. Once you have had some experience in laying out circuits using
a pen, then you may well want to go over to this method anyway.
Whatever type of symbols you
use, they are laid out on a sheet of dimensionally stable, translucent polyester film, usually working over a precision 0.1" grid for accuracy.
The master layout, which is a positive, is then placed over some copper clad board which has been
coated with a layer of photosensitive
lacquer and which is also etch resistant. In amateur PCB making, you will be using a positive coating with unwanted etch resist being dissolved off when the board is developed. It is possible to have negative resists for certain
applications.
Two types of symbols are usually
used - one is similar to dry transfer
lettering where the symbols are held
on a thin film and transferred by
pressure to the polyester sheet, the other uses die -cut individual pads made from a pressure sensitive
crepe material and held in rolls on an adhesive backing. Tracks come in
both dry transfer types and crepe
rolls and all symbols are available in
many sizes and shapes. You can also have the choice of
working at 1:1 sizing or 2:1. For
commercial layouts, 2:1 is invariably
used as it gives much more accurate
and neat layouts but you have to
a better feel for component spacing
and sizing. Which type of symbols you use
is up to you. I don't like dry transfer
symbols because although they are
easy to apply, you can't move them once they are in place. You will almost certainly find that this has to
be done at some stage during a
board layout, especially when alter-
ations are needed after a first attempt doesn't work because you
left some components out. They are also fragile and disintegrate when
touched, and if you use crepe tracks,
the pressure sensitive adhesive on the back of the tracks will pull off dry transfers if you touch them. Hence I use them very infrequently.
The big advantage of die -cut symbols and tracks is that you can
move them around quite a few times (officially not recommended but it doesn't cause any problems for the
amateur) so a layout can be modified quite easily. One of the major sup-
pliers of symbols are Chartpack Ltd
and their products are available through several outlets. There is a vast range of symbol and track widths available and all sorts of shapes for specific applications. Symbols for IC's and other multi -
legged beasts can be obtained - in fact these are made on a pressure sensitive backing film which is left on the artwork so you don't get the same problems as with dry transfer
types.
The home constructor can make
do with a fairly small selection of
pads for his designs. I would suggest
pad diameters of around 2.03, 2.54,
3, 4.06 and 5.08mm, with track
widths of 0.7, 1.0, 1.5, 2 and 3mm
for general use. They are not cheap (a roll of 100 symbols is around £8
and tracks are about £1.50 per
16mm reel) but they do last a long
time and can be used again if you are
careful in the way they are applied.
As well as full rolls, you can get
smaller ones (Maplins supply these)
but they are relatively more
expensive - you will be surprised at
the speed with which they are used
up, expecially on double sided
boards!
You will also need a roll of 16 pin
D IL IC symbols (about £5 for 100) these can be cut down to 14 and 8
pin, or used end to end for 20 pin and larger - they are also cut down the middle so that they can be used for
0.6" spacing DILs. Other symbols available are edge connectors, transistor pads, teardrops and junctions.
An artwork knife (scalpel and
blades) is essential for laying out the
symbols and is used for moving
them around and cutting tracks. Die cut symbols can either be applied directly from the roll with pressure,
or (and I find this easier) they can be
transferred to a piece of masking
tape and then moved to their correct positions on the layout using the tip of the scalpel.
The crepe tracks (they resemble the very old fabric insulating tape) are quite flexible and can be laid in straight lines or curves to suit your
requirements. When cutting the tape
at a junction with a pad, do be careful not to apply too much
pressure with the scalpel blade. The
knack will come with experience and will avoid cutting right through the
pad and the symbol - besides
destroying the symbol for future use, it may also provide a 'track -break' when etching later. Make sure that the track doesn't obscure the central
hole in the symbol pad as this will provide the drill point later.
HAM RADIO TODAY JANUARY 1987
please mention HRT when replying to advertisements. 73G4NXV
19
More equipment . . .
Once you have produced your master artwork, you can use it to
transfer the track pattern to a photographically sensitised PCB
board. The best results are obtained by exposing a photographic image of the master because the thickness of
the pads and tracks does cause
some slight light diffusal around the edges when it is being exposed, so giving a slightly less sharp image on the PCB. In practice, providing the master artwork is held in intimate contact with the photoresist coating by pressure from foam, the results are perfectly acceptable. The photosentitive coating is normally Ultra Violet sensitive and for a positive resist, exposed areas can later be dissolved away in a developer, usually a dilute solution of sodium hydroxide, leaving the wanted track pattern.
The photosensitive board can either be purchased ready made in single or double sided form or made up at home using clean copper clad board and an aerosol or liquid photosensitive coating. The latter are obtainable from various sources, but I personally have never had much
success with them, there is a definite knack required to get an
even coating and I don't seem to have it. If you don't get the coating even, you stand the risk of having some of the tracks vanish later on. This method is worth a try, being much cheaper than the ready made boards, especially if you make a mess of a presensitised PCB and have to throw away several pounds worth of capital. It is also worth bearing in mind that ready made
boards deteriorate slowly and should be used within three months or so.
Exposure
Having got your board you have to expose it. This is where a bit more cost comes in as you really need a UV exposure unit and commercial ones are not all that cheap (£50 and up), but they do come with a timer covering the usual 6 to 10 minute period of exposure. It is possible to make your own in a wooden enclosure as the UV lamps are obtainable individually but you need to make
sure that the illumination of the
exposure area will be even by using
some reflective material and a
diffuser and of course you can time the exposure manually.
You can use a photoflood or even
sunlight if you want to put up with very long exposure times but these methods tend to be erratic and daylight without sun can require unusably long exposure times. Another possibility is to use a health type UV lamp; once a method for
holding the artwork and board
against each other has been worked
out, the exposure will always be constant as long as conditions remain the same each time.
To expose the board on a proper
UV lightbox, the black plastic
protective film is peeled off the board
and the master artwork is placed (track side up) against the photo -
resist so that the image is the correct way round. This is then placed face down onto the exposure unit, the lid
is closed using the foam on the
underside to give an even pressure and the timed exposure made. Some care should be taken when handling the sensitised board - as long as the light is subdued you should be
OK, but don't wave it around in
sunlight.
Developing the image
The next stage is to remove
unwanted resist using a developer, the exposure having rendered the exposed resist soluble. The developer is usually a dilute solution of sodium hydroxide, the board simply being placed in the solution and agitated whereupon the un-
wanted resist dissolves in a few minutes - don't be tempted to rub it with your fingers to speed things up as, other than dissolving your
finger, you are also likely to remove wanted resist.
Safety
Like ferric chloride, sodium hydroxide (otherwise known as caustic soda) is not nice stuff to get on you or your clothes, so handle it with care. If you feel a soapy liquid on your hands then wash it off immediately with lots of cold water and always seek medical advice if you should get some in your eyes.
Also, when making up the
solution to the specified dilution, always add the crystals or pellets to
the water, never the other way round
as the reaction is exothermic
(generates heat) and can cause
caustic solution to spit back over the user. Caustic soda is obtainable in
sufficiently pure form from Chemists
(Boots) as drain cleaner and is sold, quite cheaply, in tubs.
Try to make up the solution in
small quantities (roughly two level plastic measuring teaspoons added to 600m1 of cold water) as required and discard after use (wash away
with lots of water) as it rapidly
absorbs carbon dioxide from the air and forms sodium carbonate in the solution - effectively weakening it. If you do try to store it for a week or so, then use a plastic bottle full up to the top, do not use glass as the solution will attack it! If the solution
is too weak, the image will not
develop at all, and if too strong, all the resist including the wanted bits is likely to be dissolved away.
When all the unwanted resist has dissolved, pick up the board
using plastic tongs (being careful not
to touch any resist) and wash for at least 5 minutes under cold running
water to remove all traces of
developer, then leave to dry off. You may find on examination that there
are small areas where tracks are touching that shouldn't, or a bit of resist hasn't fully dissolved - these can be carefully removed using a pointed scriber or a compass point. It is worth checking the board
carefully before etching as it is much
easier to correct than when etched.
Any areas where there are track
breaks can also be touched up with an etch resist or spirit marking pen and left to dry.
The board is now etched in the
normal manner, washed and dried. I find it best to drill the board before the resist coating is finally removed
as you will have to clean it again anyway after drilling. There should
be pilot etched areas at the centre of each pad from the artwork so that
you get a properly centred hole each time - if you can see that some of these haven't etched out (as often
happens) a quick pop with a centre punch is called for. When all the holes are drilled and the board is cut
to the correct size, the resist can be removed with meths and thoroughly cleaned afterwards.
If you are in a screaming hurry
it is possible to solder directly at this
point as the resist will disappear as
soon as heat is appled - it leaves a bit of a messy result but the joints
20
please mention HRT when replying to advertisements. 73 G4NXV
HAM RADIO TODAY JANUARY 1987
are good. Alternatively, it can be tin plated using the electro-deposition method or sprayed with protective solderable lacquer. Tin plating has the advantage that it considerably
enhances solder flow during assembly leading to much better
joints.
Double sided boards
All the above remarks about
making PCB's using master artwork have assumed that the design is
single sided, so you may be
wondering how on earth you make a double sided board and get the two lots of artwork to line up? This is how you do it. Take a strip of spare PCB material of the same thickness as you are going to use, about 6mm wide and a bit longer than the board. Tape one piece of the artwork to it along the longer side with the tracks
facing away from the strip. The remaining piece of artwork is then taped to the other side of the strip so that all the holes line up. The sensitised PCB is then placed
between, taped in place (outside the track area) and exposed on each side separately.
UV light safety
Ultra Violet light (known as Ultra
Violent light in some circles!) is damaging to the human eye and under no circumstances should you look directly at the light source or operate a light box with the cover
off.
Ground planes
Those PCB's which utilise a
continuous ground plane on the top side require that you clear away the copper around component lead entry points that are not earthed. For small one off boards you can do this with
a drill of suitable size twisted
between the fingers, having deter mined which holes need clearing Wrapping a piece of Elastoplast around the shank of the drill will avoid blisters if you are doing a lot of holes. You can also purchase a
special tool that fits around the
outside of a 1mm drill and will route out a circle of copper for you.
The elegant way to do it is to produce another piece of artwork with all the clearance holes on it. This is normally done by using suitable diameter pads as though you were laying out another board, each one placed over a pad on the inverted track side artwork that
needs to be cleared. A (non UV) light
box over which you can work will
make alignment much more accurate
- again this could be made quite
easily.
When all the pads are in place,
the artwork is photographically
reversed so that the pads become clear areas and the rest opaque. This is quite easy to do at home as you can buy reversal film that is UV sensitive and can be developed using
a cheap aerosol spray (both from RS Components). With a bit of juggling, you can also produce combinational artwork that has both a groundplane
and tracks on it but this isn't
recommended for the beginner.
Complete PCB making kits
You can go out and buy
everything you need to make a PCB as a complete kit. There are two that I know of. The first is a Prototyping kit sold by Cirkit which includes a UV exposure unit, thus making it a bit expensive at first. It also contains a precision grid, developer, pre sensitised PCB's, etching chemicals and trays, plus a 12v drill, colletts,
bits, materials for making photo-
graphic labels/developer, rub -down
transfers and full instructions, all for around £146.
The other one is the CM100
system, obtainable from both Cirkit and Maplin, but cheaper at £70 from the latter. This does not require a UV
exposure unit but instead makes use
of Autopositive photographic film
which is exposed using a photoflood
supplied (also used for the UV
photoresist). It is intended for reproducing layouts that have been published in magazines and will copy these in positive form ready to use with the presensitised PCB supplied.
Thus you will have to buy any
symbols yourself if you are actually preparing any layouts. Included in the
kit is the Seno etching system
already referred to and various other
things required, including a liquid crystal thermometer.
I would personally tend to buy everything separately over a period
of time but you may prefer the
convenience of the kit if you can put
up with what you get. All the kit chemicals etc can be replenished
separately.
Suppliers of PCB materials
Cirkit Holdings plc, Park Lane, Broxbourne, Herts EN10 7NQ. Tel: 0992 444111. Stock: Plain/sensitised PCB's, symbols, chemicals, complete PCB making kits, drills, drafting film, polyester film, Seno system, Autopositive film. Catalogue available at W H Smiths.
RS Components Ltd - Electromail, Dept 101, PO Box 33, Corby, Northants NN17 9EL. Tel: 0536 204555. Stock: Plain/sensitised PCB's, symbols, chemicals, exposure units, tin-plating chemical, HSS/tungsten drills and stands, prototyping boards, UV sensitive reversal film. Tin coating 551-514 for 750g-41 of solution. Aerosol lacquer 554989. Invaluable catalogue costs £2.50.
Maplin Electronic Supplies Ltd, PO Box 3, Rayleigh, Essex SS6 8RL. Tel: 0702 552911. Stock: Plain/sensitised PCB's, symbols, chemicals, photosensitive spary, complete PCB making kit, exposure units, drills, Seno system. Catalogue available at W H Smiths. The phone number for Technibond (suppliers of TEC200 copier film)
was incorrect last month. The correct number is (0494) 448791.
HAM RADIO TODAY JANUARY 1987
please mention HRT when replying to advertisements. 73G4NXV
21
ETiICgf? rho0t0myEM7TweG7atoJres
The finished article - the 2 to 80m transverter.
In the final part of the Two to Eighty metre transverter project we show how to fit the PCB to the heatsink and give the transmit strip alignment
details.
Last month we looked at construction and alignment of the receive section. In this part we turn
to the transmit section by first
mounting the PCB on the heatsink and connecting the PA.
1. Drill the holes for the PCB
mounting and IRF120 PA device in
the heatsink as shown in the
drawing (page 31, December HRT). You can if you wish drill only the two T03 mounting holes and use the T03 insulating washer to mark the holes for the gate and drain. Be sure to get these two holes nearer the edge of
the heatsink. Deburr all holes on both sides and then clear off the
anodising around the area of the two PCB mounting holes on the ribbed side. 2. Solder into the PCB two one inch
lengths of tinned copper wire for
subsequent connection to the gate and drain of the PA device. 3. Insert a 6BA x 12mm long RH
screw into each of the PCB
mounting holes on the heatsink from the ribbed side and tighten up with
a lockwasher and two half nuts. Smear a small amount of heatsink
compound on both sides of the T03 insulating washer and place it in position on the ribbed side of the sink. Carefully place the IRF120 on top of the washer, taking care not to handle the gate pin during this and
subsequent operations (this is static sensitive. 4. Pass a 12mm x 6BA RH screw plus plain 6BA washer through the
outside IRF120 flange mounting hole
and insert an insulating bush into the
heatsink on the other side. Add a lockwasher and one nut to tighten. Repeat with the other hole but add
a solder tag on top of the insulating
bush before fixing. Bend up the tag. 5. Check with a multimeter that the
case of the IRF120 is isolated from the heatsink.
6. After checking that there are no protruding wires on the underside of the PCB, fit it into place and secure with a lockwasher and nut. Solder the tag of the IRF120 to the wire
coming from near T3 and cut off any excess.
7. Bend the source pin of the IRF120 close to the PCB and solder directly
to the top foil - it will assist the efficiency of the PA if this
improved by the
addition of a small piece of copper,
brass or tin foil to extend the
earthing area between the pin and PCB surface.
8. Solder one end of C52 to the IRF120 tag with as short a lead as
possible, then solder one end of R52 to C52, again with short leads and
finally the other end of R52 to the gate pin.
9. Connect a 50 ohm dummy load
and power meter to the HF antenna
connection and check that both RV4 and RV5 are turned fully anticlockwise. Place an ammeter in series with the power leads (capable initi-
ally of measuring up to 1 amp). Earth
the PTT pin to switch to transmit. Make a note of the current reading (should be around 200mA), then slowly rotate RV4 until the current has increased by 100mA. Then repeat with RV5 until a further 300mA increase is observed. These readings should increase smoothly with no jumps - any erratic jumps with RV5 either indicate a faulty
preset or that the PA is unstable, due
either to an incorrect transformer
winding/connection (T314) or other construction fault.
10. Remove the PTT connection and
22
please mention HRT when replying to advertisements. 73 G4NXV
HAM RADIO TODAY JANUARY 1987
increase the ammeter setting so that you can read up to 5 amps. Then
connect up the 2 metre transceiver. On FM or continuous carrier CW
with the power output set to between 1 to 3 watts, switch to
transmit on 2 metres at 144.65MHz. A power output of at least 15W or
more should be achieved. Adjust RV1
carefully until the power output
starts to drop by about 1 or 2 watts.
If the power doesn't drop then either
the 2m rig is delivering more than the
required power or the value of R45 will have to be increased (say to 150/220 ohms) to reduce the drive
to the mixer. Peak the cores of L6/7 to 144.650MHz. Total currrent consumption on transmit should be
approximately 4 to 5 amps at
maximum output and a supply of +13.8V DC. 11. If you cannot get any power output, make a careful check of all components and soldering in the driver/PA areas. If the PA or driver will not take any current when the
bias presets are adjusted, check that
around 5.6V is present on ZD1. If so and volts are present at one end of the 22k resistor feeding the gate of
either driver or PA, but no volts are on the actual gate, then it is probable that the gate has been punctured during assembly and the device concerned will have to be replaced. Otherwise, a logical fault finding progression and the services of an
oscilloscope should provide a location for the fault. High current
consumption with drive applied but no power output would point to T3/4 or some other part of the output circuit.
Voltage checks are provided but these are only a guide and may differ in practice, especially the gate bias voltages on Q9/10. A 30kohm/volt analogue meter was used for the measurements, which were taken on receive.
The transverter should now work on SSB - with the relays
changing over as soon as modulation is applied. The delay before changing back to receive can be set with RV3.
Note that due to slightly different hold -in voltages, all the relays will not drop out at exactly the same time. If you seem to have too much
drive on SSB, make sure that your rig
(if it is of a type with a Hi/Lo power switch) does actually reduce power on SSB and not on CW/FM only.
Applying 10W of SSB directly to
the PCB will result in the demise of
the input circuits. It is possible to use
a higher power rig to drive the board,
but the connection to the rig will
have to initially pass through a relay -
switched (controlled via the PTT pin)
external power attenuator to reduce input transmit power to 1 watt.
In use, the receive gain should be
set so that the 2 metre rig is not
overloaded at night when signals on 80 metres are at their strongest.
If transmit is controlled directly by the PTT connection rather than via the RF VOX, note that about 130mA will pass through the PTT switch from the relays - if this is too much, add an external PNP switching transistor to control the
PTT line.
A complete kit of parts for the transverter is available from Cirkit
Distribution, Park Lane, Broxbourne, Herts ENID 7NQ priced at £59.70
inc VAT and post. It includes a ready
drilled/tinned PCB and all com-
ponents required, including heatsink.
-A ELECTRONIC AND 0527 71 165
KELLY/COMMUNICATION EQUIPMENT
3 STOKE ROAD ASTON FIELDS BROMSGROVE WORCS B60 3EQ
BEST PRICES EVER ON ALINCO MOBILES & HANDHELDS
We will sell your equipment on commission basis. Part exchange trade in? 3 month warranty on all second hand
equipment sold.
Please ask for the best deal to suit you. We also stock, Microwave Modules, DRAE, Tal Aerials, RSGB publications, Mutek, Starmaster keys.
MANY SPECIAL OFFERS
RING FOR DETAILS
OPEN 6 DAYS A WEEK
EVENINGS BY APPOINTMENT
24hr Answerphone
VISA
Books for radio amateurs
AERIAL
r,cEsSORtES
RVSU
" MAANSDTS
ELLIOTT
THE `HAM SHACK'
ELECTRONICS
JAYBEAM APPOINTED AMATEUR DISTRIBUTOR ANTENNAS
osv
OLD MAN TO
1111111141."
RIGS, ANTENNAS, SWR BRIDGES,
POWER SUPPLIES, TEST GEAR,
COMPONENTS, MORSE KEYS, COAXIAL
CABLES, ROTATORS, MICS, PLUGS
AND SOCKETS, SWITCHES
Call us on (0533LOO ) 553293
OR COME AND
K AROUND AT
26/28 Braunstone Gate, Leicester
80m TRANSVERTER
As featured in this Issue!
An inexpensive method of getting onto the popular 80m band using your existing 2m multimode transceiver. This
kit is designed for use with a low power 1-3w 144MHZ input, making it a suitable compaion for such rigs as the FT290R. The transverter will provide a minimum of lOw output at 80m. Kit includes all components including PA.
transistor and heatsink.
Stock No. 41-03409 £59.70 inc. VAT. & Post.
Cirkit Distribution Ltd
Park Lane, Broxbourne, Herts EN10 7NQ Telephone (0992) 444111 Telex: 22478
HAM RADIO TODAY JANUARY 1987
please mention HRT when replying to advertisements. 73G4NXV
23
Sony ICFD7E6000
The thought of reviewing a small
receiver like the Sony ICF 7600D left
me a little sceptical. How could such a small package work well? Having
been brought up in the world of the AR88D and the CR100 where one needed a long wire and an ATU it seemed a little beyond me that a radio so small would be more than
many MHz. So we just press the
'FM' button on the front panel, select the frequency, press the 'Execute' function and away we go! However, here in the UK most of our medium and long wave broadcasters give
their wavelengths and not their frequencies, so if we programme in 197 (metres) we end up on longwave
You don't have to be big to be beautiful -Mick
Senior, G4EFO, gives a listeners -eye view of Sony's hi -tech portable.
a mere 'toy' on the shortwave bands.
This receiver measures 7 (W) x 43/4 (D) x 11/4 (H) inches and immediately puts paid to the old story that 'big is beautiful'. It is a portable receiver which has great versatility and I have reviewed it with the SWL and traveller in mind. In this review you will not find great lists of facts and figures that would baffle all but the most scientific mind and need a fully equipped radio laboratory to prove or disprove. It is an honest 'hands on' appraisal of a useful little receiver giving the user a big window to the world.
Frequency Coverage
On VHF the receiver covers from 76MHz to 108MHz and this covers the broadcasting band in the States and Western Europe. I find it a little puzzling why it goes only to 76Mhz,
because if it had gone down to below 68Mhz it would have been
very useful for listening to Eastern Block DX. On LF, MF and shortwave the coverage is continuous from 153kHz to 29.999Mhz.
The receiver is fully synthesised and the frequencies are programmed in from the front panel in a manner similar to operating a calculator. On VHF and shortwave this presents no real problems, after all we are all
used to our local radio station
announcing its VHF frequency in so
instead of the bottom end of medium wave. This, I must admit, is a small problem and I do notice that more and more stations are giving their medium wave frequencies as well as wavelengths.
The frequency coverage is
programmed in steps like most synthesised radios. Its steps and bands are listed below:
1. Longwave 153-519kHz in 3kHz steps
2. Mediumwave 502-1610kHz in 9kHz steps*
Photo. 1 The Sony ICF 7600D - front view
#fittole
ICF-7600
inftlefoali WNW%
>6Y OS4MM1SS OOOOOOOOOOOOOO somme**** MOSSSWNISSOM*SSiRS.S4**4 OOOOOOOO
esaesee*ss*e*e*e*m**a*s*a olonamse4 OVIIVORSOSSOS,WSS *************
MO
*** S *** 111000SOSSOP **** ****
0011111S7*S*MS OOOOOOOO SWOOts OOOOO
OOOO OP*MSOSS**StOltS OOOOOOOOOO OOOOO RSSOSUGSA, OOOOO OSSIISStsgS OSSIOSS6 OOOOOOOOO die OOOOOOOOOO
OOO O SSASKUSSON484(SV OO*O OOOOOO
3. Shortwave 1.615-29.995MHz in 5kHz steps
4. VHF 76.0-108.0MHz in 100kHz steps
*switchable 10kHz option available for receivers being used in the USA.
All of these 'steps' are inter-
nationally agreed channels, so there is no problem of not being able to listen to the station of your choice.
If you wanted to programme in
your favourite net on one of the amateur bands however, don't be
surprised when the receiver defaults to the nearest 5kHz. For example, your local club has a Sunday net on 3.712MHz, so you programme this in and what happens? Well the synthesiser defaults to the nearest 5kHz
channel and you end up on
3.710MHz. Although this sounds terribly alarming it's not that bad, one
of the function switches on the
receiver allows you to compensate for this and I will explain its operation later. So much for the frequency coverage of this receiver, it's 'channelised' as many things are nowadays, but in most cases it's very convenient.
4
0
24
please mention HRT when replying to advertisements. 73 G4NXV
HAM RADIO TODAY JANUARY 1987
Photo. 2 Left side
Functions
Photo 1 shows the front of the receiver with its various controls and below I have given a brief explanation of their functions. The instruction book supplied with the receiver is very comprehensive and covers all the operating points. 1. Clock. This operates in 24 or 12 hour mode and it also has an alarm function. 2. On/Off. Switches to control the
radio.
3. LCD. Display that tells you the fre-
quency mode of reception and
whether you are on short, medium, long or VHF. Alongside the LCD is a
tuning LED indicating maximum
signal strength. 4. Enter. This button allows you to enter your chosen frequency into the
memory.
5. Tuning. On this panel you can enter your chosen frequency mode
or select one of the 10 preset
memories. 6. Band Select/Tuning. By using just
the up/down tuning buttons the receive frequency is altered in
channelised steps. When the 'band select' button is used in conjunction
with the manual tuning buttons, various frequency bands can be
selected. These include: VHF, LW, MW and the 75, 60, 49, 41, 31, 25,
21, 19, 16, and 13m broadcast bands. 7. Start/Stop. This button allows you to scan any of the preset bands mentioned above.
Further controls are found on the
left side of the set (see Photo 2). The
sensitivity switch is, in reality, an attenuator. This allows the received signal to be varied by approximately
10 to 12dBs, and helps to reduce the
effects of cross modulation and
other strange mixes when operating
the receiver near to high power
transmitters. Next to the sensitivity switch is the external antenna jack socket which is used for attaching a longwire or perhaps an external VHF beam antenna. A point to remember
however, is when an aerial is plugged
into this socket it disconnects the internal LW/MW ferrite rod aerial, so
Photo. 3 Right side
you will not be able to receive broad-
casts on these bands. The tape
socket, which is next in line, allows the user to tape their favourite pro-
grammes. For the technically minded the output spec from this socket is .775mV (-60dB) into 1 kilohm. Next
to this is the earphone socket which allows personal reception of pro-
grammes - I wish more people
would use this function when out in public places! The socket has an impedance of 8ohms. The other socket on this side is for an external
power supply, its requirements are
6 volts, but don't worry, Sony supply
a PSU as standard with this receiver.
Photo 3 shows the right hand side of the receiver. The controls available on this side start with the volume control on the left, which gives an output of up to 200mW at 10% harmonic distortion. This may
not sound much but in practise there is more than sufficient output.
The tone control is a two-way slide switch, the circuit consisting of
a simple filter network which tailors the audio response for either music or speech. I mentioned the Mode/
Fine tuning control earlier in the text:
when in the 'norm' position the
receiver will tune its pre -selected
channels but when you select 'fine' and use the fine tuning control, the receiver frequency can be tuned plus
or minus 5kHz which allows the
receiver to be tuned in between the preset channels, although this function does not operate on VHF. The final position on this switch is for SSB/CW reception and is perfectly adequate for this use. The fine tune control operates when switched to
SSB.
Practical Tests and Observations
The manual supplied with this receiver doesn't give any performance figures and being a portable receiver it is difficult to conduct proper tests without completely dismantling the radio. I have however conducted some signal tests and these figures combined with practical evaluation results give a good indication of the receiver performance.
An early review in the WRTV
Handbook described the receiver as one of the best and I would certainly
go along with that assessment,
however the WRTV Handbook also says ". . . sensitivity only so-so. Early
The complete 7600 package, radio, handbook, earplug, aerial & PSU.
HAM RADIO TODAY JANUARY 1987
please mention HRT when replying to advertisements. 73G4NXV
25
samples unstable on SSB" which I
did not find to be the case. The
sensitivity is very good even when used with its own built in telescopic
aerial and the sensitivity and stability
were very good on the model that I had. The measured sensitivity was better than 4uV for 10dB S +N/N on the shortwave bands which translated into laymans terms, meant that whilst holidaying in Peterborough I was able to hear all the members of the Billinghurst and District net in Sussex on 80m with the telescopic
aerial. On medium wave the sensitivity drops to around 10uV, but this
is still good enough to hear the
Hilversum 3 network loud and clear on 675kHz from my home in deepest
Sussex.
The image rejection on AM was good and measured at better than 50dB - a further 10dBs being added when the pre -amp was switched out. The sensitivity switch operates
on all bands and gives a 10dB signal increase at VHF. On VHF the sen-
sitivity once again was good with plenty of French stations being audible on its own telescopic aerial. The measured sensitivity was better
than 1.OuV (S/N ratio 20dB). The only complain( that I would have about the VHF section is that the AM rejection is poor, I could hear my own local fire service transmitter loud and clear. When the receiver was put onto the signal generator it confirmed the initial practical findings, I certainly would not have expected this. Looking at it from the viewpoint of those people who like listening in to the emergency services it's very good. When external aerials are connected to this receiver the performance is really pretty good, with some promising DX being heard on VHF.
Summary
The recommended retail for this receiver is £179.99 inc VAT, which I feel is a little high. Perhaps around the £150 mark would make it more
attractive although talking to my
local Sony dealers they appear to sell quite a few ICF7600D's. In all, I think
that it makes an excellent companion for the traveller who wishes to keep in touch with the world or just listen to the local radio station. It's just about small enough to slip
into a jacket pocket, although its
weight of just under 11/21bs (including
batteries) does make it feel a little bulky. The receiver comes supplied with a receiving handbook, carrying
case, power supply, longwire aerial, earphone, 12v lead for use in the car and an external aerial plug. It is simple to use and its audio quality is good. Perhaps 9 out of 10 to Sony would be fair for this remarkable little receiver.
AK D TEL. 0438 351710
Unit 5 Parsons Green Estate Boulton Road Stevenage
Herts SG1 4OG
MAIL ORDER DEPT. Stock Items Normally Despatched within 48 hours,
21 days latest.
People said we had disappeared from the face of the earth. They were wrong WE MOVED!!
Our new larger premises allow us to hold bigger stock and to introduce Watch t j space over the coming months.
products.
Still going strong in its 4th year at the original price. How do we do it?
WA1
WAVEMETER
£24.95
7.1I7m7±mo
Our Waveabsorption meter for 2 Mtre transmitters meets
RP J licensing r'grmnts range
120Mhz to 450Mhz, very sensi-
tive, can also be used as field
strength meter within its range. Requires PF'3 type battery (not
supplied).
HFC1
CONVERTER
£49.00 GPA1
PRE -AMP
£24.95
For the FRG 9600965 our new HE Converter, connects to the aerial socket, and powered direct from the 8 Voft o/p of the FRG 9600. Tune from 100, 1Mhz to 160Mhz, gives tuning range of 100Khz to 60Mhz, uses double balanced mixer, with low pass filter on input * Can be supplied with BNC termination for other scanners *
2 Mtre RF Pre -amp using
BF961 dual gate FET 18 db gain: Low noise, 2Mhz Bandwidth SO 239 termination 25
AKD
Z.= GIPPt
watts through power. Failsafe
switching, can be left in line when not required, auto RF sensing
even at 1/2 watt can be factory tuned between 28-170Mhz.
* Can also be tuned for 6-4 mtrs *
A SELECTION OF OUR MOST POPULAR FILTERS (SEND SAE FOR FULL RANGE DATA SHEET)
RBF1 A range of UHF notch filters (for inner only) stocked at the following frequencies: 435MHz 170cms) channel 36 (for radar blips), 846MHz (RAF Boulmer interference) can be factory tuned from 420MHz tc
TNF2 A range of notch filters specifically tuned for the frequency of interference on inner and outer bandwidth >1Mhz (2Mhz above
100MhzI. VERY LOW INSERTION LOSS TYPICALLY <0.5db. Stocked
IDEAL FOR CLUBS OR EMC GROUPS FOR EVALUATION OF INDIVIDUAL
SITUATIONS
890MHz.
£6.75 each for the following frequencies: 14Mhz, 21Mhz, 27.5Mhz ICB),
To order quote RBF1/ followed by type.
HPF1 Low insertion loss high pass filter with capacitive braid breaker for
50Mhz, 71Mhz, 145Mhz. Also spot tuned at any frequency to
300Mhz.
£6.75 each
To order quote TNE2/ and the frequency.
DK1 FILTER KIT
Kit of all filters in our range (11 in all) except for RBF1/
846Mhz.
£41.70
use with UHF TV, VIDEO & PRE -AMPS. HPFS
£6.75 each BB1 Transformer braid breaker >25db at 30Mhz, often used with other WE ALSO STOCK TORROID RINGS 0,E2.50 PER PAIR.
High pass fitter with transformer braid breaker, better performance filters in our range for very severe interference. Ideal at the input of
than HPF1 but the insertion loss is a little higher. 1-2db best for VCR and PRE -AMPS.
£6.75 each
severe problems for UHF only.
£7.00 each
RSGB NOW STOCK OUR FILTERS AND MEMBERS CAN OBTAIN THEM AT A DISCOUNT FROM RSGB HQ.
ALL PRICES QUOTED ARE CORRECT AT TIME OF GOING TO PRESS AND INCLUDE
VAT, POSTAGE & PACKING
ALL OUR PRODUCTS CARRY THE USUAL 2 YEAR GUARANTEE
ALSO AVAILABLE FROM LEADING AMATEUR RADIO DEALERS
* EMC PROBLEMS *
PHONE OUR TECHNICAL HELPUNE ON THE ABOVE PHONE NO. BETWEEN item & 12 NOON ANY WEEKDAY.
Props: RT & VEL Wagstaffe. Technical Adviser: John Armstrong
26
please mention HRT when replying to advertisements. 73 G4NXV
HAM RADIO TODAY JANUARY 1987
:FARNBOROUGH COMMUNICATIONS
97 OSBORNE ROAD, NORTH CAMP,
FARNBOROUGH, HANTS
Your mail order enquiries for YAESU and ICOM range
of products are always welcome and are dealt with
promptly and politely. Call us now for that little extra
: service.
CD [1COM]
Stockist of Drae psu's, Jaybeam and Cue Dee
Antennas, Microwave Modules, Oskerblock SWR,
CDE, RSGB publications, quality cables, our own
TVI filters, Welz, Bencher, Mirage amps.
Open Monday to Saturday 10am-6pm
ACCESS + H.P. Available + BARCLAYCARD
Telephone: Farnborough (0252) 518009
RADIO SOFTWARE
48K SPECTRUM & SPECTRUM 128
RTTY
QSO Review, Printer Dump, Type Ahead, Memories, etc
Transcelve £8.50
Both Require Filter.
Receive Only £8.50
C.W.
Self Tracking 8/30 WPM, Type Ahead, Memories, etc
Transcelve £8.50
Receive Only £8.50
SLOW SCAN TV
Save to Printer, Brightness, Contrast & Inverse Controls.
Tuning Aid, etc
Receive Only £7.00
FILTERS
Unboxed RTTY Only
£6.00 C.W. Only
£7.00
Boxed RTTY/C.W. Switchable
£11.50
Ditto with Tuning LED
£13.50
TERMINAL UNITS
No space to fully describe this superb unit
£45.00
(Send for Full Details and Specification)
S.A.E. for full details of these and other Products.
J.E.P. ELECTRONICS LTD New Road Complex, New Road, Kidderminster, DY10 1AL
Tel: (0562) 753893
AMATEUR ELECTRONICS UK
G6X1314
GIRAS GBUUS
R.A.S. (Nottingham)
Radio Amateur Supplies
Tel: 0602 280267
Visit your Local Emporium
Large selection of New/Used Equipment on Show
AGENTS FOR:
F.D.K. AMEN ICOM
ACCESSORIES: Welz Range Microwave Modules Adonis Mics
DRAE products BNOS Linear, and PSUs
YAESU ALINCO
Mutek Pre -Amps Barenco Mast Supports
KENPRO
Agents for VODAPHONE & CELLNET
AERIALS: Tonna, Halbar, Jaybeam, New Diamond Range of Mobile Whips
Bring in your secondhand equipment for sale
JUST GIVE US A RING
Monday: CLOSED Tuesday -Saturday: 10am to 5pm
3 Farndon Green, Wollaton Park. Nottingham NG8 1DU Off Ring Rd, between A52 (Derby Road) & A609 (Ilkeston Road)
MORSE CODE PREPARATION
Cassette A: 1-12 wpm for amateur.
Cassette B: 12-25 wpm for professional examination preparation.
Each cassette is type C90.
Price of each cassette (including booklets)
£3.95
Morse key with separate battery (PP3) - driven solid-state oscillator and
sound transducer produces clear tone for sending practice.
Price of key with electronic unit
£8.95
Price includes postage etc. Europe only
MH ELECTRONICS (Dept H) 12 Longshore Way, Milton, Portsmouth PO4 8LS
FOR DISPLAY ADVERTISING
PLEASE RING DAVE GADSDEN G4NXV
01-437-0626
HAM RADIO TODAY JANUARY 1987
NEW BBC LOCATOR AND WORLD MAP
This program displays a world map with daylight and darkness zones updated every few minutes and realtime clock. Accepts an input of lat&long, QTH or Maidenhead locator, NGR or one of nearly 250 worldwide placenames.
Prints distance, bearing, VHF contest score (50km rings), reciprocal bearing and, distances over 1600km, the long path distance and
bearings. It marks the distant station on the map
and draws the great circle to it. Converts
locators and NGR to lat&long, and lat&long to Maidenhead locator.
Tape £7. For other computers we have our original locator program (no map) at the same
price.
TX -3 RTTY/CW/ASCII TRANSCEIVE PROGRAM
This is a really top -class program with almost every feature you could imagine. Full details are in the previous two adverts. It doesn't need an expensive T.U. (though it works superbly with one). For BBC -B and CBM64, tape £20. If you already have our RTTY/CW transceive program, return it with your order for a £10 discount.
TIF1 INTERFACE
Specially designed to reduce computer noise, this has 2 -stage switchable filters on receive and outputs for MIC, PTT and KEY on transmit. Kit £15 (assembled and tested PCB + connectors and cables but not MIC connector or box), complete assembled, boxed with all connections £25 (state rig). Using more than 1 rig? No problem, state extra rigs and add £3 for each.
For the listener we have the
RX-4 MULTIMODE RECEIVE PROGRAM
Lots of features and performance for receiving RTTY, CW, SSTV, AMTOR. Spectrum needs no hardware, BBC -B, CBM64 and VIC20 use TIF1 or a TU on RTTY and CW. Tape £25.
All our BBC -B and CBM64 programs are also available on disc at £2 extra. (BBC: state 40/80 track). Prices include VAT and p&p, 1st Class inland, airmail overseas, normally by return. Eire, C.I., BFPO deduct 13%.
technical software (HRT)
Fron, Upper Llandwrog, Caernarfon LL54 7RF Tel: (0286) 881886
A.
27
gMogiogaP
rse ti ecoder
Very many amateur shacks are now
equipped with some sort of
computer, and morse reading
programs are readily available for
most of the popular types. A
sending is displayed as a space, and
any unrecognisable characters are
displayed as an asterisk. Word
wrapping is prevented by printing a
CR/LF sequence if a space is
memory (RAM) is provided. This is unusual, but the Z80 itself contains sufficient register storage for our needs, provided that certain restrictions are understood. Firstly, there
A nifty gadget to decode and print morse (via a Centronics printer) from Phil Green, G4PHL.
can be no PUSH or POP's to the
stack. There can be no stack without RAM! Secondly, no subroutines may be used, since without a stack there
disadvantage of using the home
micro in this way is that the machine
is fully occupied for long monitoring
periods, preventing its use for other purposes. Few machines offer true multi -tasking, so the morse reader must be interrupted if any locator,
bearing, or logging programs need to
be run. By the time a station has been located and the beam set up accordingly, the contact may well
have finished.
This circuit can be regarded as a simple morse-to-centronics con-
verter which releases the main station computer for more
interesting tasks, and gives a hard copy printout for later perusal. The
decoded after the 70th character typed (the interrupt page register is used for this count!).
The software can track accurately between about 8 to 24 wpm, but as in any decoding program,
does need reasonable quality morse. It can therefore be usefully employed
as a training aid by attaching a
practise key to the input. All alphabetic characters, numbers, and punctuation signs are catered for as well as the barred procedural characters.
System Considerations
A glance at the memory -map
will reveal that no read-write
is nowhere to store the return
address. Similarly interrupts cannot be used, though this does release the I register for other purposes. In fact a trick method of calling sub-
routines is used, as follows:
LD IY,S +7
JP SUB //
//
; IY holds return address
; call the subroutine ; next instruction . . .
The subroutine itself would be
arranged as follows:
//
; code . .
// JP (IV)
. . . code ; Pseudo return
instruction
circuit hardware is based on an idea
from the Zilog handbooks, this being
the simplest Z80 implementation
+5V
imaginable. Comprising of only four chips, it is a well tried and tested
circuit with the benefit of having
very little to go wrong. Constructors
RI 820R
CI
R2
190
820R
17
*IT
R3
330R
24
6
A010
MREO 9
18
ADDR
+5V 21
with little experience in microprocessors can approach this project with confidence, especially since all the chips used have been seen on sale at various rallies for a fraction of the normal retail price. Never pay more than 50p for a Z80!
Operation
When the power is first applied, the power -on -reset operates and the
XTAL 4MHz CLOCK
+5V
R4 3k3.
NOTE IC1 = 7414 IC2 = 280A IC3 = 2716 IC4 = PIO D1= 1N4148
1C02 0q
6
ICld
IC1e
RD
0
IC2 DATA
IC3 DATA
IC1f
2
PORT B STROBE
0
STROBE
0
20 IORQ
26 RESET
7 MI
4 35
36 - CE RD DATA !OKI IC4
MI PO A PORT
+5V
PORT A STROBE
0
B/A 6 C/D 5
0=A1=A8O 0
Al
0
0 = DATA 1 = CONTROL
title "Morse to Centronics converter" is displayed on the printer. If good morse is then applied to the port A
KEY
r,VORATU
R5 10k
BIT 1
CENTRONICS DATA
input, using a logic low for tone, and
logic high for no tone, the decoded text will be printed out. A pause in
Fig. 1 Circuit diagram of the morse decoder.
28
please mention HRT when replying to advertisements. 73 G4NXV
HAM RADIO TODAY JANUARY 1987
+5V
TTL OUT TO PIO BIT 1
NOTE: IC5 = NE567
Fig. 2 Diagram of the decoder interface.
Provided the IY register is not used during the subroutine, this works fine. Remember we cannot PUSH IY to save it!
Construction
The four IC's used are the Z80 itself, a parallel input/output chip, a 2716 EPROM containing the morse reading software, and a 7414 TTL chip which provides the 4MHz clock and power -on reset.
Veroboard was used for all of the prototypes, however almost all the
tracks are cut adjacent to each IC pin, interconnections being individu-
ally wired. The physical layout of the board is not at all critical, and could be made a little larger if required. Wiring should follow the table provided, veropins being used for the power connections. Where two connections are made to one pin, for example the data lines and address lines 0 and 1, it is easier to thread
two wires through first before
soldering. Lay all the wiring neatly between the IC's rather than taking the shortest route between two pins.
0000 3E 4F D3 02 3E OF D3 03 AF ED 47 21 A8 Al 7E 23 0010 B7 28 OC D3 01 11 00 18 1B 7A B3 20 FB 18 EF 3E 0020 14 47 OE 01 21 00 00 FD 21 2E AO C3 E5 AO 30 40 0030 24 7C CB 3F CB 3F CB 3F B8 38 OB FD 21 42 AO C3 0040 E5 AO 30 DB 18 F5 FD 21 4D AO C3 E5 AO 38 El 2C 0050 78 CB 3F BD 38 10 FD 21 5D AO C3 E5 AO 30 FO 7C 0060 85 67 2E 00 18 CA 7C CB 3F B8 CB 11 26 00 18 09 0070 2C 7D CB 3F CB 3F B8 30 20 FD 21 80 AO C3 E5 AO 0080 30 EE 24 78 CB 3F BC 38 42 FD 21 90 AO C3 E5 A0 0090 38 FO 7D 8C 6F 26 00 18 D7 79 FE 01 28 16 FD 21 00A0 A5 AO C3 07 Al 11 00 OC 1B 7A B3 20 FB FD 21 B4 00B0 AO C3 07 Al 2E 00 26 00 FD 21 BF AO C3 E5 AO 30 0000 F5 24 78 CB 3F BC 30 FO C3 46 AO 78 CB 3F 80 BD OODO 38 07 78 85 CB 3F 47 18 07 FD 21 EO AO C3 07 Al 00E0 2E 00 C3 46 AO 50 59 06 05 OE 00 DB 00 E6 02 81 00F0 4F D9 08 01 8E 00 OB 78 B1 20 FB 08 D9 OF 10 EB 0100 79 FE 06 42 4B FD E9 79 D9 01 32 00 21 40 Al ED 0110 Bl 01 31 00 09 7E D3 01 D9 ED 57 3C ED 47 79 FE 0120 01 20 19 ED 57 FE 46 38 13 3E OD D3 01 11 00 OC 0130 1B 7A B3 20 FB 3E OA D3 01 AF ED 47 OE 01 FD E9 0140 01 06 17 15 OB 03 1D 09 1F 07 18 OA 1B 04 05 08 0150 19 12 OD OF 02 OE lE OC 16 14 13 30 38 3C 3E 3F 0160 2F 27 23 21 20 2E 6A 2D 4C 35 BA 7A 73 47 2A 52 0170 29 00 20 41 42 43 44 45 46 47 48 49 4A 4B 4C 4D 0180 4E 4F 50 51 52 53 54 55 56 57 58 59 5A 31 32 33 0190 34 35 36 37 38 39 30 3D 2E 2F 2C 40 2D 21 3F 3A 01A0 3E 29 3C 2A 00 00 00 00 47 34 50 48 4C 20 4D 6F 0180 72 73 65 20 74 6F 20 43 65 6E 74 72 6F 6E 69 63 01C0 73 20 43 6F 6E 76 65 72 74 65 72 2E 20 20 38 2D 01D0 32 34 20 57.50 4D 2E OD OA OA 00 FF FF FF FF FF 01E0 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 01F0 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
Fig. 3 Hexadecimal listing of the EPROM contents.
Insert the 7414 first, apply power, and listen for the 4MHz clock or a harmonic on your commuications receiver, to confirm operation. When inserting the larger chips, be carful
not to bend any pins under the chip.
The input/output connectors were fashioned from 16 pin turned
DIL sockets, by cutting them to form two eight -way strips. These can be
conveniently mounted directly alongside the PIO. Suitable plugs can be made in a similar manner by cutting a 16 pin header.
An alternative to Veroboard is
the specially designed PCB, available
through our Reader Services Department. Details of how to order it are available at the end of the article.
It is important the IC sockets are used for projects like this one since this encourages experimentation and allows for the occasional "blow-up" without too much disappointment. Junk box and surplus components
can be tested on the board without risk of damaging anything expensive.
4MHz crystals were used in all the prototypes since these were to hand, however 3.579MHz colour burst crystals would probably suffice
giving a reduced speed coverage of say 7 to 20 WPM without altering the software. If this is acceptable then by all means use them and save a little. 4.433MHz British colour crystals may work equally well for
CPU CONTROL
Z80 CPU pin -out diagram.
{DATA
PORTA.
mITIVNAtLuE
Z80 PIO pin -out diagram.
ID
HAM RADIO TODAY JANUARY 1987
please mention HRT when replying to advertisements. 73G4NXV
29
Memory and I/O Map
EPROM: 0000 - 07FF reflected at 2k intervals
I/O
00 - 03 reflected at 4 byte intervals
PORT A: data - 00 software configured for key or TU input control - 02
PORT B: data - 01 software configured for Centronics output
control - 03
Photos of the prototype decoder boards.
say 10 to 30 WPM. If in doubt about a crystal in the junk box, try it! Avoid spending a lot on simple projects. That way you can build more!
A simple NE567 type of terminal unit is sufficient, and a sample circuit is provided. Others have appeared elsewhere in magazine articles and there is scope here for further experimentation. In the absence of a signal the input port pin should be pulled high by, say, a 10k resistor if the TU does not default to this condition. Ouput is via a ribbon cable carrying 8 bits of data and a strobe signal. No busy signal is required from the printer due to the limited speed requirements.
Other Use,.
The board will adapt very easily to other uses simply by changing the EPROM, and has been used, among projects, as an RS232 to Centronics converter (and vice versa), a code converter, a musical box, an EPROM blower interface and a musical doorbell. The author can supply details of the software that is available if you send him an SAE at the address given below. Don't be frightened of microprocessors and associated chips, or regard them as useful only within a computer. They are after all only components, and cheap and readily available components at that!
EPROMs may be programmed from the hex listing shown, or preprogrammed EPROMs may be purchased from the author for £3 each at: 6 Yews Close, Worrall, Sheffield S30 3BB.
The author would like to thank Geoff Taylor, G4KPU, for building the
second prototype, and Stewart
Ward, G6BCM, for photographing both prototypes.
Special PCB
The PCB for this project is
available from our readers services department, price £9.40 including VAT and P&P. Orders should be sent to: Argus Specialist Publications Ltd, Readers' Services, 9 Hall Road, Hemel Hempstead, Herts HP2 7BH. Credit card orders can be placed on 0442 211882 (office hours only, for the present). Please remember to quote the board reference number, which is R8701-1, or you're liable to get the wrong PCB! Please allow up to 28 days for delivery.
30
please mention HRT when replying to advertisements. 73 G4NXV
HAM RADIO TODAY JANUARY 1987
a a
0a C
D
C
a
Ta C
IC2
0
0
a
a
a
a
0
a a
a
a
0a
a a
00
D
D 0 0
IC3
D
0 0
0
0
= THRU BOARD LINK TO OTHER SIDE
UNNUMBERED SUPPLY DE -COUPLING CAPACITORS = 10n -100n CERAMIC (VALUE NOT CRITICAL)
Fig. 4 Component placement for the decoder
a
a
D
C
0
C
DO
C
0
C
0
C
POWER
+V SUPPLY
D7
C IC4
C
C
C
DO
C
ST
a
ST
a
D7
a
C
o00
000
K TUB
0. DO
ST
AUDIO IN
OV
K = LINK FOR KEY TU = LINK FOR TERM UNIT
Components List
RESISTORS
R1,2
820R
R3
330R
R4
3k3
R5,R8* 10k
R6*
100R
R7*
12k
RV1* 4k7 preset potentiometer
CAPACITORS
C1
1n0
C2
100u 12V electrolytic
C 3*,C 4* 100n
C5
470n tantalum
C6
1u0 tantalum
SEMICONDUCTORS
IC1
7414
IC2
Z80A CPU
IC3
2716 programmed EPROM
105* NE567
IC4
280P10
D1
1N4148
MISCELLANEOUS
XI
4MHz (or close) crystal
Centronics printer plug; circuit board
(PCB or stripboard); wire, etc.
* Denotes an item used in the terminal unit - may be omitted if not required.
HAM RADIO TODAY JANUARY 1987
please mention HRT when replying to advertisements. 73G4NXV
31
Fig. 6 Underside PCB layout (full size).
32
please mention HRT when replying to advertisements. 73 G4NXV
HAM RADIO TODAY JANUARY 1987
QUARTZ CRYSTALS
STOCK CRYSTALS
CRYSTALS FOR 2 METRES
HC25 £2.15 FOR ONE CRYSTAL £1.96 WHEN 2 OR MORE PURCHASED
HC6 £2.15 FOR ONE CRYSTAL £2.05 WHEN 2 OR MORE PURCHASED
TX CRYSTALS
RS CRYSTALS
CHANNELS IN STOCK
HC6/U 8MHZ 30PF
44 MHZ SERIES RES
RO TO R7,S11, S20 TO S23
HC25/U 12MHZ 30 & 40PF
: 44 MHZ SERIES RES
: RO TO R7 S8, TO S23& S32
HC25/U 18 MHZ 25 & 20PF
14/15 MHZ 20 & 30 PF
RO TO R7 S8, TO S23 & S32
HC25
SCANNER XTLS (NOT SR9)
: RO TO R7 S8, TO S23 & S32
full lost available on request please send SAE.
4 METRE CRYSTAL FOR 70.26 IN HC6/U AT £2.40 each
TX 8.78250
RS29.78000
FUNDAMENTALS FREQUENCY RANGE 5 TO 50 kHZ
50 TO 150 kHZ 150 TO 500 kHZ 160 TO 999 kHZ
1 TO 1.5 MHZ 1.5 TO 2.0 MHZ 20 TO 6.0 MHZ
6 TO 21 MHZ 21 TO 25 MHZ
MADE TO ORDER CRYSTALS
OVERTONES
PRICE
FREQUENCY RANGE
£21.00 3rd OVT
21.00
T065.00 MHz
£11.00 5th OVT
60.00
T0110.0 MHZ
£7.80 5th OVT
110.00
TO 125.0 MHZ
£11.90 7th OVT
125.00
TO 175.0 MHZ
£10.75
£5.10 £4.75 £4.55 £6.50
DELIVERY
2.0 TO 175.0 MHZ 2 TO 3
5 TO 999.9 kHz 6 to 8 1 TO 1.499 MHz 3 to 4
PRICE £4.55 £5.10 £7.40 £10.00
weeks weeks weeks
70CM CRYSTALS £5.00/pr of £2.50 each
For Pye PF1 PF2 & PF70 series Wood & Douglas and FDK MULTI U11SUB(433.2)SU20 RBO RB2 RB4 RB6 RB10 RB12 RB13 RB14 RB15. ALSO for MULTI U11 ONLY SU16
Unless otherwise requested fundamentals will be supplied for30pf load capacitance and overtones for series resonant operation HOLDERS:- PLEASE SPECIFY WHEN ORDERING-else HC25/UsuppliedforXTLSabove3 MHz HC13/U
SU18
6.200 kHz HC6/U & HC33/U 170 KHz-175 MHz HC18/U & HC25/U 2-175 MHZ
CONVERTER CRYSTALS IN HC18/U AT £2.85 each.
DISCOUNTS: Price on application for10+ units to same frequency/spec or bulk purchases of mixed frequen-
22,000, 38.666, 42.000, 70.000, 96.000, 101.000, 101.500, 116.000 FREQUENCY STANDARD £2.75 each HU6/U 1000kHz 3.50MHz 5.00MHz 10.000MHz 10,7000MHz HC18/U 10000kHz 7.00MHz 10.70MHz 48.00MHz 100.00MHz Also HC6/U455kHz £3.25 each
des. We supply FREE xtals for use in U.K repeater& COMMERCIAL CRYSTALS: available on fast delivery and at competitive price& Please send for list stating interests EMERGENCY SERVICE: for XTALS 1 to 125 MHz. Add the surcharge for each XTAL Days refer to working days. 4 days +£12,6 days +£7, 8 days +E5. 13 days +E3.
TONEBURST, I.F. & MPU CRYSTALS IN HC18 £2.25 each.
CRYSTAL SOCKETS HC25 £0.20 es HC6 £0.25 ea MINIMUM ORDER CHARGE £1.50 unless ordered
7,168MHz {for 1750 HZ Tone), 10.245 (for 10.7 I.F.) 3.2768 5.0688 14.3180 15.00000
YAESU CRYSTALS for FT101's FT901 & etc £4.00 each Many available ex stock (A list is avaialble on request pse send S.A.E.)
with crystals TERMS: Cash with order post Inc to U.K & ireland Cheques& P.O.'s to OSL LTD. A stamped addressed envelope with ALL enquiries please.
P.O. Box 19 Erith Kent DAB 1 LH
ALL PRICES ARE
Telephone: 01-318-4419 24Hr Ansafone: Dartford (0322) 330830
EX VAT PLEASE ADD 15% Telex: 8817271 GECOMS-G (Attention QUARTSLAB)
8
SPECTRUM COMMUNICATIONS
MANUFACTURERS OF RADIO EQUIPMENT AND KITS
CB TO 10 FM CONVERSION BOARDS, suits all UK FM CB rigs to give 29.31 to 29.70MHz. Size only 63.40.13mm. Built and aligned board SC29 £15. Or send your rig and we'll fit it. £28 inc. return P&P for mobiles. £31 inc. for base rigs. MULTIMODE CB CONVERSIONS, send your 120 channel rig and we'll convert it to give 28.01 to 29.70MHz in straight sequences without gaps. Colt 1200DX, Cobra 148. Hy Gain 5, Multimode 2, Major M360, Tristar 747 & 777, Super Star 360, Concorde, etc., £62 inc. return P&P. Jumbo or Colt Excalibur 1200, £65 80Channel rigs such as Stalker 9 or Major M588 are modified to give 28.31 to 29.70MHz in straight sequence without gaps. £45.00 inc. return P&P. 200 Channel in 4 bands of 50 are converted to give 28.00 to 30.00MHz or 28.00 to 29.70MHZ as required. Super Hy Gain 5, Lafaeyette 1800, Super Star 2000. £45.50 inc. return P&P. Nato 2000 £52.50, Super Star 2000-5.40CH £70. Colt
1600, 4.40CH, £65.50. FREQUENCY MODEM adds FM to synthesized rigs with 455KHz IF. Type FM 455, PCB kit £6.50, PCB built £9.50. FREQUENCY DEMODULATOR adds FM to receivers with 455KHz IF, suits R600 & R1000, FRG7 & FRG7000. Type FD455. PCB kit £5.50. PCB built £730. FREQUENCY MODULATOR adds FM to synthesized rigs or rigs with clarifier, Type FM1000, PCB kit £3.00, PCB built £4.00. RECEIVE CONVERTERS 2, 4 or 6 Metre aerial input with 10 metre IF or 4, 6, 10 or 20 metre aerial input with 2 metre IF, 26dB gain, low noise with OSC output. Types RC2-10, RC4-10, RC6-10, RC4-2, RC6-2, RC10-2, RC20-2, PCB kit £17.25, PCB built and tested £24.50, Boxed kit £25.00, Boxed built and tested £35.25. TRANSMIT CONVERTERS, 2, 4 or 6 M, aerial output with 10 M. IF, 10 25mW to 1W drive 500mW output, matches receive converters. Types TC2-10. TC4-10, TC6-10, PCB kit
£16.50, PCB built £25.75, Boxed kit £25.50, Boxed built £38.00. TRANSMIT & RECEIVE CONVERTERS, combination boxed unit, 500mW output, types TRX2-10, TRX4-10, TRX6-10, Boxed kit £49.00, Boxed built and tested £89.50. TRANSCEIVE CONVERTER, single board version of receive & transmit converters, 500mW output, with repeater shift facility. Types TRC2-10, TRC4-10, TRC6-10, PCB kit £39, PCB built and tested £54, Boxed kit £54, Boxed built and tested £83.25. TRANSMIT AMPLIFIER, unswitched, suitable for Transmit Converters, Transceive Converters and MEON, 500mW in. 20W min output. Types TA2U2, TA4U2, TA6U2 PCB
kit £40.50, PCB built & tested £48.75. Boxed kit £45.00. boxed. built and tested £53.00. RECEIVE PREAMPS 2, 4, 6 or 10 metre. RF & DC switched, 0-2dB variable gain, low noise, 100W handing. Types RP2S, RP4S, RP6S, RP1OS. Also masthead version DC coax fed, types RP2SM, RP6SM. PCB kit £12, PCB built and tested £16.75, Boxed kit £20.25, Boxed built and tested £27.00 NOISE SQUELCH squelches rig when noise is high. Allows reception between noise bursts. Type NS1000, PCB Kit £7.25, PCB Built £10.25.
VAT & P&P INC PRICES Delivery within 14 days subject to availability. 24 hr answering.
UNIT B6, MARABOUT INDUSTRIAL ESTATE, DORCHESTER, DORSET. TEL: 0305 62250
Ill
Attention FT757, FT77 and FT707 owners . . .
z
f --.110:16M 1011
XI in OR 0 6
12 16 2.4
Ell 11111111
Modern solid state rigs designed to have a CLEAN output can not be 'flat topped' by screaming into the mic.But a vast increase in average output can be obtained without objectionable distortion
by using the DATONG AUTOMATIC RF SPEECH PROCES-
SOR - gives push button selection of up to 30db of clipping.
CALL IN AND LISTEN TO THE TAPE WE MADE with 2 FT75Ts and Si'signals - certainly with my voice the Datong
is more effective than any legal linear. Datong auto RF speech processor, £82.80 p.p. Ready wired for FT757, FT707 or FT77. With connecting lead - (no mic plug to solder!).
HEAR THE TAPE. (OR BUY THE PROCESSOR) AT:
RE
AMATEUR ELECTRONICS/ HOLDINGS, 45 Johnston Street, Blackburn BB2 lEF.
(0254) 59595.
AMATEUR ELECTRONICS LTD., 504 Alum Rock Road, Alum Rock, Birmingham B8 3HX. 021-327-1497/6313.
WEST LONDON COMMUNICATIONS
STORNO 800 PMR SETS EX MET
POLICE CHOICE OF 20
£90 EA.
CB RADIO CHOICE OF 20 £10-£16 EA.
AERIALS FROM
£2.50 EA.
STORNO CAR PHONES 900SA
CHOICE 20
£100
61 FAIRFIELD ROAD, WEST DRAYTON
West Drayton
447767 (STD 0895)
(10 Lines
3 MILES FROM LONDON AIRPORT
WANTED. Best prices paid for second hand equipment.
Please note it is illegal to operate a transmitter without a licence. The following equipment does not meet D.T.I. approval, all sets are sold without
crystals and sold as seen and without warranty.
SHOP OPENING SOON IN ONGAR, ESSEX 20th DECEMBER
PYE MOTORPHONE CHOICE OF 10
£15 EA.
PYE CAMBRIDGES AM/FM CHOICE OF 20
£10 EA.
PYE 2945 HIBAND FM
£200 EA.
PYE WESTMINSTER AM/FM CHOICE OF 25
£25 EA.
PYE F30 BASE STATION CHOICE OF 5
£50 EA.
PYE UHF BORESTATION TRANSMIT & RECEIVE £10 EA.
PYE VANGUARDS CHOICE OF 25
£3-£5 EA.
STORNO 700 EX CAR PHONES CHOICE OF 10 ..£20 EA.
GEC BASE STATION CHOICE OF 10
£5-£10 EA.
STORNO 600 EX CAR PHONES CHOICE OF 20 ..£15 EA.
STORNO FM LOW BAND SETS CHOICE OF 10 .. £25 EA.
PYE CAMBRIDGE BOOK MOUNTS AM/FM (CHOICE OF 20
COMPLETE WITH CONTROL GEAR)
£10 EA.
STORMO 700 DASH MOUNT LOW BAND FM . £30 EA.
CLEAR TONE SET HI -BAND FM
£25 EA.
OLYMPIC AM HI -BAND
£30 EA.
HI REPEAT HI -BAND FM
£30 EA.
HAM RADIO TODAY JANUARY 1987
33
1 T59408 N7 transceiver. Modes )USB, LSB, CW, FSK, FM, AM. Frequency range) transceive 180 to 10 metres, receive 150 kHz to 30 MHz. Power input) 250 watts PEP, AM 140 watts. Power supply) internal psu, 240 VAC. Features) 40 memories, 2 VFOs, provision for internal ATU, keyboard frequency entry, SSB IF slope tuning, CW variable band width, CW full break-in, IF notch filter, Audio filter, variable CW pitch, optional voice synthesizer etc.
a T89308 HP transceiver. Modes> USB, LSB, CW, FSK, AM. Frequency range) transceive 160 to 10 metres, receive 150 kHz to 30 MHz. Power input) 250 watts, AM 80 watts DC. Power supply) internal psu, 240 VAC. Features) 8 memories, 2 VFOs, optional internal ATU, CW till break-in, MB IF slope tuning, CW variable band width, IF notch filter, audio filter etc.
3 T84408 113' transceiver. Modes) USB, LSB, CW, FSK, FM, AM. Frequency range) transceive 180 to 10 metres, receive 100 kHz to 30 MHz. Power input)200 watts PEP, AM 110 watts DC. Power requirement> 13.8 VDC, transmit 20 amps. Features) 100% duty cycle, optional internal ATU, CW full break-in, IF shift, notch filter, 100 memories, keyboard frequency entry, manual or automatic bandwidth selection optional voice synthesizer etc.
4 234305 N7 transceiver. Modes>USB, ISB,
CW, AM and optional FM. Frequency range)transceive 160 to 10 metres, receive 150 kHz to 30 MHz. Power input>SSB 250 watts PEP, CW 200 watts DC, FM 120 watts, AM 80 watts. Power requirement> 13.8 VDC, transmit 20 amps. Features>8 memories, 2 VFOs, memory and programmable band scan, IF shift, notch filter etc.
5 TS58011157 transceiver. Modes) USB, ISB, CW. Frequency range) 180 to 10 metres. Power input) 220 watts PEP, CW 180 watts DC.
34
Power requirement) 240 VAC. Features) pair of 8146B valves in PA, variable band width tuning, notch filter, IF shift, RF speech processor etc.
8 1353087 N7 transceiver. Modes> USB, LSB, CW. Frequency range> 160 to 10 metres. Power input) 220 watts PEP, CW 180 watts DC. Power requirement) 240 VAC. Features) pair of 6148B valves in PA, IF shift, notch filter etc.
7 0311180 station monitor. Features) TX and RX waveform monitoring, trapezoid linearity check, two tone test generator, wide band oscilloscope, panoramic display (band scan) with optional BS8 unit having 40 kHz/200 kHz sweep width. Versatile and invaluable station accessory.
8 TL9AS NY linear amplifier. Modes) SSB, CW, RTTY. Frequency range> 180 to 10 metres. Power input> SSB 2000 watts PEP, CW 1000 watts DC. Drive> 80 watts or more for full output. Power requirement> 240 VAC, 14 amps. Features) class AB2 grounded grid amplifier using a pair of EIMAC 3-500Z valves.
9 T8870 Quadbandtransceiver. Modes> USB,
LSB, CW, AM and optional FM. Frequency range> 40, 15, 10, 6 metres. Power output) USB, LSB, CW, FM 10 watts, AM 4 watts. Power requirement)
13.8 VDC, 4 amps. Features> 80 memories, 2 VFOs, keypad frequency selection, optional general coverage receive board etc.
10 TX801A two metre mobile. Mode) FM. Frequency) 144 to 148 MHz. Power output) 25 watts. Power requirement> 13.8 VDC, 5.5 amps. Features) compact, 2 VFOs, 5 memories, priority alert, memory and programmable band scan, Hill repeater facilities, includes external speaker, mobile mount and up/down microphone.
11 TX4113 seventy centimetre mobile transceiver. Mode> FM. Frequency) 430 to 440
MHz. Power output) 25 watts. Power
requirement) 13.8 VDC, 6.9 amps. Features) digital code squelch, tilting front panel, 211F0s, 5 memories, priority alert, memory and programmable band scan, till repeater facilities, includes external speaker, mobile mount and up/down microphone.
1/1 TX2113 two metre version of TX4113 mobile transceiver.
13 T1588803 two metre mobile transceiver.
Mode) FM. Frequency range> 144 to 146 MHz. Power output) 45 watts. Power requirement> 13.8 VDC, 9.5 amps. Features) large display, illuminated keypad, optional digital channel link, high output power, optional voice synthesizer etc.
14 TH413 seventy centimetre handheld
transceiver. Mode> FM. Frequency range> 430 to 440 MHz. Power output) 1 watt or 150 mW. Power requirement) 7.2 VDC from supplied nicad pack. Features) compact, slim and lightweight, thumbwheel switch frequency selection, full repeater facilities etc.
18 THa l3 Two metre version of TH413.
18 TR880051two metre handheld transceiver. Mode> FM. Frequency range> 144
to 148 MHz. Power output) 2.5 watts or 0.3 watts in low power position. Power requirement) 8.4 VDC from supplied nicad pack. Features) compact and lightweight, 10 memories, memory scan, programmable band scan, keyboard frequency selection, digital code squelch, full repeater facilities etc.
17 TR38003 Seventy centimetre version of T328003. Note, does not include nicad or mains
charger.
18 TS7113 two metre base station
transceiver. Modes> USE, ISB, CW, FM. Frequency range> 144 to 148 MHz. Power output) 25 watts. Power requirement) internal
HAM RADIO TODAY JANUARY 1987
power supply 240 VAC or 13.8 VDC at 8.5 amps. Features) 10 Hz step dual VFOs, IF shift, auto mode selection, 40 memories retaining frequency, mode, simplex or repeater shift, tone burst. Programmable band scan, memory scan, free running or stepping VFO, digital code squelch etc.
19 T88118 seventy centimetre version of T87118.
20 TR7818 two metre mobile/base station
transceiver. Modes >1.735, LSB, CW, FM. Frequency range) 144 to 146 MHz. Power output) 25 watts. Power requirement) 13.8 VDC at 6 amps. Features) auto mode selection according to band plan, excellent receive performance, 2 VFOs, 12.5 kHz steps on FM, alert channel, all mode squelch, memory frequencies can be transferred
to VFO, optional digital channel link, optional voice synthesizer, full repeater facilities etc.
Al T8780 dual band base station
transceiver. Modes) USB, LSB, CW, FM. Frequency range) 144 to 146 and 430 to 440 MHz. Power output) 10 watts. Power requirement) 240 VAC or 13.8 VDC at 5 amps. Features) full coverage of two metres and seventy centimetres in one transceiver, 10 memory channels, 2 VFOs, memory scan, band scan, IF shift, full repeater facilities, VOX operation, free running or click stop VFO etc.
22 52000 general coverage receiver.
Modes) USB, LSB, CW, FM, AM. Frequency range) 150 kHz to 30 MHz. Power requirement) 240 VAC or 13.8 VDC. Features) optional internal VHF converter covering from 118 to 174 MHz, 10 memories storing frequency, band and mode. Memory scan, programmable band scan, all mode squelch, tone control, slow or fast AGC, high and low impedance aerial terminals, remote switching from internal clock (tape recorder), receiver muting etc.
17 18
22
4
7
3
8
19
15 14
18
20 Al
a
13
12
11
1
9
10
the TRIO range
from
LOWE ELECTRONICS LTD.
Chesterfield Road, Matlock, Derbyshire DE4 5LE Telephone 0629 2817, 2430, 4057, 4995 Telex 377482 LOWLEC G
HAM RADIO TODAY JANUARY 1987
35
Review
When Yaesu introduced the FT29OR
transceiver, they took a large share
of the 2m market, where a multi-
purpose set was very attractive to
both newcomers on the band as well
as seasoned operators of FM -only
sets who wished to give SSB a try.
It has many facilities and allows a
reasonable compromise for
operating mobile, fixed, and 'sling -it -
over -your -shoulder' portable. It was
inevitable that eventually a Mark II
version was introduced and 'Ham
Radio Today' have been fortunate in
obtaining one of the first models to
arrive in this country, just in time to Operators view of the new '290, bigger display
let you consider whether it is worth and cleaner layout make the rig more 'fumble -free'
twisting Father Christmas's arm!
- It may be the same size it may have the same
even switches on the dial lights for you! A mobile mount is of course
name, but don't let that fool you. Chris Lorek,
also available so if you wish you may
G4HCL, investigates this brand new rig from Yaesu.
leave the 25W unit in the car and simply slide the set in and out as
Vive le Difference!
needed.
at the block diagram (Fig. 1) will The LCD display is much larger and
show the increase in circuit hence easier to read, especially at
It's exactly the same size, the
same weight, covers the same frequency range with the same
complexity. The internal photographs
reveal a totally different construction
method has also been used,
odd angles as would sometimes be encountered in mobile or portable use. The front panel, although having
power and modes of operation, but employing chip components to fit all one less knob to twiddle than its
more expensive, selling at £399 at the new circuitry inside the box.
predecessor, sports a separate
the Leicester Show. So how does it
The aerial supplied is now clarifier control, no more pressing
differ? At first glance it appears to be
simply a cosmetic face-lift - even the specifications are roughly the
sensibly a helical whip, mounted at
the top of the set by means of a BNC
connector. How many FT29OR
buttons to use the main dial for this
purpose. A minimum SSB step size of 25Hz makes tuning easier and
same, but first impressions can owners are there out there with an allows far better FSK performance
certainly be deceiving. Many unbroken telescopic whip? An for RTTY etc, when using SSB.
amateurs moaned at the FT29OR for optional helical was the norm for
its 'fiddly' operating requirements. portable use, but this suffered from
What Does It Offer?
For instance, to switch on the dial the inconvenience of having to
light, the noise blanker or the low - unscrew it every time an external
As with its predecessor, the set
power mode required a fumble aerial was connected at the rear to around the back of the set, not the avoid damaging the PA. Many ideal thing to do on the road or amateurs operated the set mobile as
is described as an all -mode multi-
purpose transceiver. The equipment
is designed to allow it to be used
operating portable with the set in a well, which usually meant lots of either as a transportable, mobile, or
carrying case! Yaesu must have done messing around at the back of the base station set, operating from a their homework, as many of the set but not any more! With the Mkll battery supply of between 8-15.8v
shortcomings have been completely you simple unclip the battery pack DC. A plastic clip -on battery pack is
ironed out, the end result being a set and clip on an optional 25W stage, provided, which houses nine 'C' cells
offering much the same in the way this automatically disconnects the and a small PCB with switching
of facilities, but with a higher degree helical, makes RF and ALC (Auto- circuitry to allow charging of nicads
of operating ease. Internally the set matic Level Control) connections to or use of an external supply. An
is completely different and a glance the 25W power amplifier stage, and optional 25W amplifier, the FL2025,
36
please mention HRT when replying to advertisements. 73 G4NXV
HAM RADIO TODAY JANUARY 1987
may be clipped on in place of the
battery pack which transforms the set into a higher power mobile or
base set, not surprisingly you cannot
use the batteries with the amplifier fitted!
Modes of operation are FM,
USB, LSB, and CW. FM frequencies may be stepped in 50kHz, 25kHz,
and 12.5kHz increments, whilst the other modes use 2.5kHz, 100Hz, and 25Hz steps, controlled from the
front panel knob or from the
Up/Down buttons on the fist mike. Further panel -mounted buttons allow so-called 'Giant Steps' (!) of
100kHz and 1MHz. Two digital VFO's
are incorporated, each storing frequency, mode, frequency step, and TX offset information. Nine memories allow storage of frequency, mode, and TX offset and odd split -frequency working is
possible by using memories 1 and 2.
The standard 600kHz repeater shift is of course incorporated and full reverse repeater operation is available at the push of a button,
another improvement over the earlier set.
Any of the selected memories
may be scanned for activity, or the entire band searched in selected
steps when using one of the VFO's, the scan halting for a few seconds
on an unsquelched frequency before
resuming. Priority scan of memory channel 1 is possible, where that frequency is briefly sampled every
two seconds. A 'Call' button keys the transmitter whilst sending a 1750Hz tone (a 'phantom bleep'!) and the use of a second function control facility allows you to operate on low power and switch in an all mode noise blanker. A small meter, identical to the previous '290, gives an indication of receive signal strength and transmit power and indicator LEDs show transmit mode and receive busy' states. A nice touch is that the green busy LED doubles as a transmit modulation monitor and the TX LED starts flashing away when the nicads are getting low, whether you are on transmit or not.
In Use
Without further ado, the set was unpacked and connected up in the shack. Within a few seconds I had got used to operating the many functions, without needing to read the instruction book - showing that the
operating modes had been well thought out. About the only thing I had trouble getting used to was
manual stepping through the modes by repeated button pushing, I have
always been used to separate
buttons for each mode or a rotary knob. However I quickly learned that by keeping one VFO programmed to FM on the upper part of the band, and the other on SSB in the lower portion, I didn't have to touch the
Rear panel - the aerial socket has migrated to the front panel where it belongs
mode button at all. Tuning on SSB using the 25Hz
steps was a great improvement over the earlier set, the analogue clarifier was also easier to use in following drifting stations or for quick 'tweeks'
when in a net with the odd off
frequency station. The 2.5kHz steps were useful in quickly searching a frequency range for activity as well as getting from the calling channel to a working frequency. I found that I very rarely used the 100Hz steps, finding it easier to give the 'Up' or 'Down' buttons on the microphone a press instead.
On FM, the 12.5kHz steps were optimum for general tuning around,
but in my area and many others, local nets occur on wierd frequencies by today's standards, often on multiples of 10kHz from days gone by. It was
infuriating to be able to hear a
distorted QSO and not be able to resolve it - even if you tune onto frequency on SSB mode and then switch to FM the set jumps to the nearest 12.5kHz step! Also when
Top view - cleaner inside too, surface mounted nfttnnt-ot-mts are!list one of the new features
Unuet view - the trend towards dealer -only servicing continues
HAM RADIO TODAY JANUARY 1987
please mention HRT when replying to advertisements. 73G4NXV
37
RP IR/OUT I
RL Tea EAT ALC 0-A
ALC 60
06201
ATI
r3S, 2/
PA
0620/.06
L620/
n1302
T/R SR
COI.PLER
Lee
06202
2508820
an,
REG
1339M7
ALT CET
MR
133-14.81.2
-PA TRANSMIT
RECEIVE
-PA catOvOATC
scanning on FM, the set will only
stop when the signal is on frequency
- an off -channel signal, although strong enough to raise the squelch, will not halt the scan. These latter features could be considered very nice of course, but may not fulfill some operating needs. However after a little playing about, I found I
could tune in any frequency on SSB,
store it in a memory, recall the
memory, change mode and then restore it, hence gaining access to it in memory mode at least.
Because the memories store
mode as well as frequency, I
appreciated the facility allowing me to monitor S20 FM for local activity
while checking 144.300 SSB on
priority scan, giving the best of both worlds. The squelch operates on all modes which is very useful in this
respect.
On The Road
The set was then placed in my car to see how it performed mobile.
The FL -2050 amplifier was not available at the time of review, so operation was carried out both
barefoot and with a remote mounted A200 25W amp (HRT Sept '86) to get an idea of the 'balance' between receive sensitivity and Tx 'range'. After programming the memories with S20, repeater and local natter
channels, the two VFO's being set to 144.3 SSB and 145.25 FM, I set off
with great expectations. The toneburst button was reasonably placed, but after continually
fumbling around looking for the 'Rev'
button to check repeater inputs I decided to use this only from home
and programmed reverse channels in immediately following the repeater
channels, which gave an ideal arrangement. A press of the 'Up'
button on the mic was all that was
needed, at the expense of losing the
odd memory. Using the set barefoot, that is
with no external RF amplification, I found no problems in reception of DX signals but of course the low
power gave a weak signal into distant repeaters. Adding a 25W linear ensured good reciprocity, where received signals nicely
matched the reception of my
transmissions at the other end and
I did not feel the need for an external
preamp at all. SSB mobile was tested, although no QSO's resulted
- probably due to aerial polarisation
differences. The noise banker
reduced S5 ignition noise down to
inaudibility, resulting in receiving the
GB3VHF beacon either perfectly or completely drowned in noise. The
main knob was lightly detented, allowing easy SSB tuning under
bumpy road conditions.
The frequency display was very clear, at night the back illumination
worked well, but I really must have a moan about the tiny S -meter. Other Yaesu sets use a very clear
bargraph type display on their LCD's
so why could they not have
incorporated it into this one? Maybe
someone overproduced little meters!
Not very useful and it seems to me
still to be an afterthought in the
design. Having had my little grumble,
I must say it was still very readable
even at night, giving a fairly sensible
indication of signal strength although a little lazy on weaker stations. Adequate receiver audio
was available on all modes, but the
internal speaker did rattle a little on high volume settings, an external speaker at face level was used to
much better effect.
On transmit, audio reports varied
from woolly to superb, though noone whom I regularly worked commented on any difference from my usual high -spec commercial equipment audio until I told them I was using a different rig!
Inside The Box
Out came the screwdrivers and laboratory test equipment, to see what the real difference was. At first glance inside the set one gains an impression of 'there's not much in there!'. A diecast chassis
construction houses two main
analogue circuit boards, with further digital control circuitry mounted at
right angles on the front panel
moulding. The discrete components such as coils and filters are mounted
on the circuit boards topsides, but a
maze of chip resistors and capacitors
fill the undersides and the hidden
control boards. Eight separate sheets
of circuit diagrams are given as
compared to one slightly larger sheet
for its predecessor, need I say more?
A study of the block diagram shows a double conversion superheterodyne on FM, with IFs of 13.9885MHz and 455kHz, on
SSB/CW only the first IF is used. The received signal is passed through a
varicap-tuned dual gate FET bandpass front end amplifier (a 3SK122L) into the 3SK74L mixer, through two monolithic dual -crystal filters to give roofing selectivity and then to the noise blanker gating.
Here the signal is split two ways, on
SSB/CW it passes via the multi -pole
crystal filter and IF amplifiers to a
uPC1037H, where it is demodulated, the carrier injection frequency being altered to suit the mode. Note that a 700Hz offset is used for CW. The
AGC-derived squelch controls the
recovered audio gating and a uPC575 IC amplifier boosts the
i IWI.p
-
ingenious design but the plastic
hinge lugs are rather vulnerable
38
please mention HRT when replying to advertisements. 73 G4NXV
HAM RADIO TODAY JANUARY 1987
§(4
gg° a2g
--
F2t
ON
3
I
0
OO
OLL,
gig
7'E/3
IaIoo LE1J
a
-40---
goNO
3
0
6,9.8
25e
Asit
'611
0
cri
mfetl
Fi
;!
T 4T
tr
gig°
ry
04
ot
kgi
§-4
01
T
ury
At
Jn
§P
00
IF
g I
LEV
Op
p
O
H
r?.
in A
5
S
s
WV
o E
0 0
0
HAM RADIO TODAY JANUARY 1987
please mention HRT when replying to advertisements. 73G4NXV
39
Exactly the same dimensions and weight as before, but a completely new design
audio to loudspeaker level.
On FM, the first IF signal is
passed to an MC3357 IF subsystem IC (rather a strange choice as it is now getting a little dated), where the signal is amplified, downconverted
to 455kHz and passed through a
CFW455E ceramic filter and demodulated. Noise derived squelch gating is used and the audio is then passed
to the common audio amplifier
stages. AGC derived signal strength metering is used for all modes.
Frequency generation is performed by a Motorola MC145145 synthesiser under serial control from a custom HD61391A41 microprocessor, which also provides all the 'housekeeping' functions. A waxencapuslated VCO generates the final frequency minus 13.9885MHz. The synthesiser steps this in coarse increments, fine steps being performed by a digital -analogue converter driving a VCXO (variable crystal oscillator) mixing with the VCO signal to produce a lower 8MHz
nominal signal to be fed to the
synthesiser IC.
On FM transmit, a further
13.9885MHz VCXO is frequency modulated with the amplified and
clipped microphone audio to produce direct FM and this is mixed with the PLL generated frequency to achieve 145MHz. CW transmission employs on/off keying of this oscillator, simultaneously driving an audio tone oscillator, which is fed to the speaker to give CW sidetone. On SSB, the common receive carrier -oscillator is used with the uPC1037 to generate a double sideband signal, which is fed via the crystal filter to remove the carrier and unwanted sideband and mixed with the PLL signal to achieve
145MHz.
Clip -on Parts
The add-on battery case provided is made from a dark grey plastic, which hinges and splits into two sections to enable battery fitting. A very economic form of
construction is used which I feel lets
the radio down, the mechanical rigidity is such that I don't believe it will stand much rough treatment without breakage, particularly the
small securing tabs on the underside.
A very primitive, but novel, plastic extender rod allows the set's dial lamp to be switched on by mating with a similarly primitive rod inside the set which bears against a small push switch. However the battery
case design is such that the set may
be used table -top (or hill -top!)
portable with the set upright, resting on its base. This was not possible with its predecessor due to interconnecting plugs and sockets fitted
to the underside.
Although not tested, the matching FL -2025 amplifier may
also directly clip on the back in place of the battery pack. This houses a
block M57727 PA module with associated low pass filters, switching and ALC circuitry. The
ALC is usefully passed back to the FT29OR to control the peak drive power, although the RF input from the set is first passed via a power attenuator to reduce the input drive. RF is connected via a chassis mounted phono plug, the inner
conductor of this mechanically
switching the set's BNC RF feed out of circuit.
Laboratory Tests
The set was subjected to the rigours of signal generators and spectrum analysers to see how it would perform under demanding circumstances. The receiver strong signal handling was fairly good, as the laboratory results show,
equalling and sometimes exceeding
higher cost mobile sets. The
adjacent channel selectivity on FM would allow it to handle 12.5kHz spacing reasonably. On SSB, I was a little disappointed to see the filter selectivity broaden out at around the -45dB mark, three different signal generators were used to confirm this, each giving similar results. Further checks showed that this was
not due to reciprocal mixing, where synthesiser noise causes an apparent degradation, but due to the
filter passband selectivity and any IF signal hop -over occurring. In fact, Yaesu have slightly degraded their
SSB selectivity specification to 5.2kHz at -60dB, compared with
the original rig's 4.8kHz at -60dB.
This should not produce many
problems in normal 2m usage in the
majority of cases, but is worth
bearing in mind if you decide to use it with a transverter to get onto the
more crowded HF bands. The sensitivity was quite good, you
should not need to fit a preamp for normal use and was well controlled throughout the band, showing the
varicap tuned front end was doing its stuff.
On transmit, the output
spectrum was fairly clean in terms of harmonics and synthesiser mixing
products, the SSB two-tone tests showed the PA stages to be nicely linear with no excessive spreading
noted. Of particular interest was that
under ALC conditions, where the set
compensates for the operator
excitedly shouting into the mike, the
3rd order products actually reduced in level due to phase cancellation in successive stages. The power output with changes of frequency and supply voltage was very accurately controlled and the battery voltage warning LED started flashing at 8.55V, giving a useful warning that your nicads were about to breathe their last.
Peak FM deviation was too high
at low audio frequencies, though within reasonable limits at midrange. A rising pre -emphasis response up to 1.95kHz was noted, where the audio rapidly started falling off. This would account for the odd 'woolly' report noted on the air, but would help in keeping adjacent channel power down when using 12.5kHz offset channels.
0
-10
-20
-30
dB
-40
-50
-60
-70
-80
I
1
I
I
I
I
I
I
I
I
I
-4 -3 -2 -1 0 1 2 3 4 5 6 7 ,8
kHz
SSB/CW Simple signal RX selectivity
40
please mention HRT when replying to advertisements. 73 G4NXV
HAM RADIO TODAY JANUARY 1987
Conclusions
Japanese manufacturers are increasingly surprising radio users with their ability to squeeze more and more into small boxes. The FT29OR
Mkll is deceiving in this respect, possibly making you think it is just a cosmetic change where this is
certainly not so. The rig is far easier
to operate whilst offering a more rugged set through the use of chip
components. No servicing or adjustment details are provided with the set apart from circuit diagrams.
I was pleased with the rig; as with the original set it should be incredibly popular with amateurs looking for a multi -purpose 2m rig and transverter driver for the UHF bands. At just under £400, comparing its price with that of a separate mobile, portable and base station makes it an even more appealing compromise. I wonder when we will be seeing all the second-hand Mk l's?
Our grateful thanks go to
R. Withers Communications of Birmingham for the timely loan of the review set.
0
-
-20
Tx SSB Twotone intermod
'-
distortion:
E
+3dB into ALC `4.'
_._
_._
70
- 20
' -m-
1 -50
50 pp
70
%raft*, `Yam....
I
I
FREQUENCY-.
..... ........-...........11,.........
FREQUENCY ..
I
I
Tx SSB Two-
tone intermod distortion: onset of ALC
Laboratory Results Receiver
Sensitivity - Signal level in uV pd giving 12dB SINAD signal
Freq.
SSB/CW
FM
144
0.135
0.160
145
0.135
0.160
146
0.135
0.160
Adjacent Channel Selectivity:
FM selectivity - Level of increase in
interfering signal above 12dB SINAD ref, modulated with 1.5kHz of 400Hz audio
tone, to cause degradation of on -channel
12dB SINAD signal to 6dB SINAD.
Separation
Rejection
+ 12.5 kHz - 12.5 kHz +25 kHz - 25 kHz
52dB
44(1B
76dB 76dB
Blocking Rejection - Increase in interfering signal level above 12dB SINAD ref.
to degrade on -channel signal from 12dB SINAD to 6dB SINAD
Spacing
SSB/CW
FM
100 kHz 1 MHz
10 MHz
99dB 102dB
102dB
92dB 98dB 98dB
S -Meter Linearity:
S1
S5
S9 S9 +
S9+ +
0.41 uV pd 1.50 4.55
260.00 23.00 mV
Max. Audio Output: (Measured at onset of clipping) Speaker Load 3 ohm 8 ohm 16 ohm 5 kHz Dev. FM 1.2W 920mW 400mW
SSB/CW 670mW 670mW 520mW
Transmitter
Power Output and DC Current Drawn: (SSB PEP and CW/FM power outputs similar to within +/-0.5dB).
Freq MHz
144 145 146
10.8V
High
Low
2.68W/1.08A 2.68W/1.08A 2.69W/1.18A
0.38W/0.55A 0.37W/0.60A 0.35W/0.61A
13.8V
High
Low
2.68W/1.08A 2.70W/1.08A 2.70W/1.10A
0.38W/0.55A 0.37W/0.61A 0.36W/0.62A
RX DC Current Drawn lin mAI Dial lamp cu rent: 88mA extra
SSB/CW
FM
Squelched Vol Mid. Vol Max.
129 mA
191
456
108 mA
201 488
Intermodulation Rejection - Increase in
level above 12dB SINAD ref. of two
interfering signals to produce 12dB SINAD on -channel signal
Spacing
SSB/CW
FM
12.5/25 kHz 25/50 kHz 50/100 kHz
90.5d8 90.0dB 89.5dB
56dB 71dB 71dB
First IF Rejection: 81dB all modes Half IF Rejection: 99db all modes
Spurious Emissions
2nd Harmonic
3rd Harmonic 4th Harmonic 5th Harmonic
-65 dBc -67 dBc -82 dBc - 85 dBc
All other harmonics or other spurii: less than -85 dBc.
FM Deviation: 6.45kHz peak (at 400Hz), 5.3kHz peak (at 1kHz).
Toneburst Deviation: 3.20kHz TX Frequency Accuracy: +74Hz measured 20mins from switch on.
HAM RADIO TODAY JANUARY 1987
please mention HRT when replying to advertisements. 73G4NXV
41
Jan declared it was Duddy's fault and Duddy swore it was Frank's, but whoever, there we were, stuck with
a Bonk Hill Amateur Radio Clubnight on Christmas Eve. Our hall had been
prone until Duddy and Jan gave it the
kiss of life in 1975. Only Oliver has died and come back to life more often than the Bonk Hill Amateur
Radio Club, and I was, as you might
A Christmas ghost story for radio hams everywhere, by Trevor Artingstoll, GOJOE. Not for the squeamish!
booked "as for November" and that meant for four Wednesday evenings.
The fourth Wednesday in December was on the eve which Santa Claus gallops into the home straight on his toys delivery scam. The Manager was sorrowful but as firmly against
cancellation as he was against giving the Club its ackers back. "No way, gentlemen," he insisted. "The world an' its uncle want this hall Christmas
Eve an' the Club got first chance. Sorry!"
Came the night, it was as bad as the committee feared. There was Duddy, Hon Sec, never been known to miss a meeting; Chairman Jan,
flannelling away as per usual; Honest John Treasurer, always looking and sounding like a lost BBC gardening
expert; Frank Fanatic, the QRP CW DX-er extraordinary and reputedly a
household name in Chunking, where
I've heard they own one of the three amateur band TRx's in the whole of China; "Tinker" Bell the soldering whizz; and yours truly, telling this mournful tale. The other forty -odd members sensibly stayed by their
fireplaces waiting to nick Santa's christmas drinkies as soon as the kiddies went byebyes.
The club had been first formed in the early Twenties. Then, bottles
were black boxes and grizzled Fullerphone survivors from the
trenches sweated excitedly over the
latest in basket coils and prophesised the early demise of radio amateurism "as we know it" if bottles took over from spark coils.
They did and nowt much changed except that the club died in 1939, reincarnated in 1948, staggered on until 1955, died again and remained
say, in all of its deaths. Like many G2's in such clubs I like to sit back,
look as benevolent as anyone like me
can look, and let the lads get on with
it. Not so much a silent key as a
semiquavering key, you might say.
"Brrr-h!" shivered Jan, as I stood
behind him, both of us looking
through the glitterdusted window. "Seasonal, eh?" The others clustered around. Snow was falling
like a lorryload of mushrooms being
tipped against the black glass.
"Can't see my car, hardly." Frank pointed a nose like a
whippet's straight up my left nostril. "How about a carol and - and -,"
he hesitated, short of humour, "and a ghost story from someone, eh?"
Duddy trotted across the hall and waved his hands over the snoring
42
please mention HRT when replying to advertisements. 73 G4NXV
HAM RADIO TODAY JANUARY 1987
gas fire. "This hall's been up a hundred years. Should have a resident ghost after all that time."
"Was it always a meeting hall?"
asked Tinker curiously. "As long as I've lived here. And
that's about - let's see - thirty two. According to the odd minutes of meetings the Club's met here since
Hitler was a lad. Used to be an infant
school." "Ghosts!" snorted Honest John.
"I've yet to see one and I know I
never shall. Wouldn't believe it if I did see one. Go to a psychiatrist."
Frank snickered, looking in my direction meaningfully. "There could be a real evil one watching us right now. Maybe planning to materials and scare the bejeezus out of us. He swung_ away from the window and sat down. "I was here the night
Jimpy Bennet fell off the twig. Right there, where you're standing."
Tinker stepped quite quickly to one side, away from the hallowed spot. "It was on a Christmas eve!
One moment he was arguing about checking gain compression points with a tuned audio meter. The
next..:' here his voice fell full seven
decibels," . . . dead! Brain
haemorrhage!" "Dead?" echoed Jan, coming over
to us and dropping into an armchair.
"I never heard of any member dying -er- on the job, so to speak."
"Yonks back, that's why," replied
Frank, looking inwards and obviously
reading a few decades off the
timebase printed on his mind's screen. 'Just after the war it'd be; forty years ago. " Some mental picture made his lips turn down." We were in Special Ops together. He
was a hard man. No mercy in
him . . . Used his knife a lot . . . We called him The Butcher . . !"
Clearly still scanning the same
internal scene, he muttered very low, "Bled from every hole in his head. Nose; mouth; ears. Even his eyes
bled!" A respectful and rather horrified
silence fell in which Frank completed his peep into a grisly past. Arising, our grim historian moved towards
the door of the radio equipment store. " Think I'll play with the Frog . . . "The door opened, then closed behind him. Presently the
rustling of white noise signified that
he was snooping around the
radiospace of Chunking yet again. It
cut out as the earphone jack snicked
in.
Tinker swore. "Damm it! Left the
coffee jar." Jan and Honest John
arose as one from their chairs, being
fond of a hot tipple clubnights. "Wait
a bit though -"
"-Yes, in the kitchen. Saw a jar
as we came in," interrupted Duddy
helpfully. They all left like homing
pigeons, passing me as if I wasn't
there.
Drifting across the hall towards
the wall of the equipment store I
passed through it. "Frankieboy! Hey,
Frankie!"
He raised his head, adorned with
a big, rubber -padded cans, took me
in and started to howl terribly. One
after the other his screams came.
Like brakes screeching. Towards the
end it sounded more as if he was
gargling.
"Jimpy! 0 Christ! It's Jimpy! Go!
Back! Get away - for God's sake!
Ahhh-h! . . . BLOOD!!"
The blood . . .
I'm not so hard. I don't much like
giving it to people I know.
KW TEN-TEC CORSAIR II
NO FRILLS, "GIMMICKS", OR UNUSED FACILITIES - FOR THE SERIOUS PHONE/CW OPERATOR WHO WANTS THE LOWEST NOISE, CLEANEST
AND MOST SELECTIVE AMATEUR hf TRANSCEIVER ON THE WORLD MARKET
Price £1147.24 (including VAT and delivery) MADE IN U.S.A.
Other KW -TEN TEC winners
The KW -TEN TEC ARGOSY II ssb/cw transceiver £548.84
The KW -TEN TEC CENTURY 22 cw only transceiver £342.13 The KW -TEN TEC TITAN Linear Amp. 2kw pep, 1kw ccs, £2119
Plus The KW -TEN TEC RX235 Receiver, 300kHz to 29.999MHz £544 Model 920 Air band Walkie Talkie, Model 3100 series Mobile Whips 4229 2kw ATU Kit, 229 2kw ATU READY MADE,
MODEL 209 Dummy Load. etc.
KW TRAPS (original and best) for KW Trap Diple. KW TRAP DIPLE (now in 27th year of manufacture)
KW BALUN, KW ANTENNA SWITCH. etc.
ALL BACKED BY THE KW SERVICE (trusted by Radio Amateurs and Government Services for more than 30 years).
The above prices include VAT and UK carriage.
VISA, ACCESS
WRITE OR PHONE FOR DETAILS
Hire Purchase
KW TEN-TEC LTD
Vanguard Works, Jenkins Dale, Chatham, Kent, ME4 5RT Tel: 0634 815183 Telex: 965834 - A/B KW COMM G.
KW Ten Tec Ltd is an associate Company of Ten Tec Inc. of USA and a subsidiary of KW Communications Ltd.
HAM RADIO TODAY JANUARY 1987
please mention HRT when replying to advertisements. 73G4NXV
43
eEczzzonanoRroeview
OVK
OkRIC
PUT
VAST
.IOW
Tony Bailey, G3WPO, investigates the latest version of KW's Ten -Tee HF transceiver. Better than the
competition? - Read on!
Back in November 1984, we reviewed the `TenTec Corsair, an
American HF Bands transceiver for
those wanting performance but without all the (possibly unneces-
sary) frills that usually come with the Japanese black boxes. Since then,
the Mk11 version has appeared, offering improved performance and some extra facilities over that of the Mkl. It should be mentioned at this stage that although you won't find
the rig crawling with memories, synthesisers, split frequency operation
and all the other 'gadgets' of the
oriental designers, you will still have
to dig in your pocket for around
£1350 (inc VAT) for the privilege of
owning a Corsair and matching power supply. So, is this expense
justified by its performance?
First impressions
The review sample came with
the matching 240v ac power supply/
speaker (although the Corsair itself
does have an internal speaker), a full set of four IF crystal filters and the matching KR1B twin paddle keyer,
which in conjunction with the
Corsair has a simple programmable
memory. The appearance of the
transceiver has undergone a facelift since the MkI and although basically
the same layout, with one extra
rotary control, the colour scheme is
now two-tone grey with the light shade predominating. I like it - it is a refreshing change from the Japanese look-alikes and gives an
immediate impression of quality and
class.
The controls are all reasonably sized, well spaced and practical no miniaturised switches or fiddly concentric controls to hassle over. I
also have no doubt that the oriental
version of a Corsair would be accom-
modated in a box half the size of this
one, but to me, a lot of the appeal would then be lost. Incidentally, the appearance of the transceiver is not unlike that of some Drake equipment. On the front panel, there are the usual controls for AF gain, power on/off, RF gain and band select.
The Corsair II covers all the current amateur bands from 1.8
through to 30MHz with a basic
500kHz tuning range from the VFO
- thus 10m is covered in 4 segments. The mode switch selects
either normal or inverted sideband according to the normal amateur convention and has both a CW and a lock (Manual Tx) position. It does not offer inbuilt FM or AM facilities, nor are these available as options. This is a specific choice to maintain the performance on SSB and CW without concessions to the requirements of these little used modes on HF. I doubt that this will concern the buyer that the Corsair is aimed at.
Front panel functions
The main VFO tuning knob is
similar to that used on other Ten Tec
44
please mention HRT when replying to advertisements. 73 G4NXV
HAM RADIO TODAY JANUARY 1987
equipment and gives around 20kHz per revolution. I couldn't find any trace of backlash in the reduction mechanism, the only criticism being
that VFO tuning is very dead in feel and cannot be spun, although it did
its job perfectly well. The frequency readout is via a 6 -digit LED behind a filter running the length of the top of the front panel. The main MHz
and kHz digits are displayed in orange (previously red) but the
100Hz digit is still in green, a choice
which I find odd. It doesn't really add
anything to the display and if chosen to differentiate the 100Hz from the other digits, could have been better
achieved using another decimal
point instead. Also mounted along the display
section are the meter function select
switch (Ic, SWR, power and proces-
sing level) together with smaller rotary controls for noise blanker level, blanker width, ALC and pro-
cessing level. The width control is an additional function to the Mkl, and there is also a keyer speed control
which wasn't present before. The
VOX controls have been relegated to
the rear panel to make room for the extra front panel controls. As with the Mkl, PBT (passband tuning) is
offered, together with RIT (on Rx, Tx or both) plus two rates of IRT shift
(either -1.5/+2kHz or +/-4.5kHz).
AGC (hang type) can be set for fast, slow or off, and a pull switch selected attenuator offbrs 10dB of attenuation when operative; what actually
happens is that the front end RF amplifier is bypassed when the attenuator is in circuit.
A bank of five 3 -position lever switches controls the RIT functions,
plus filter select and AGC. The speed
at which the Rx/Tx changeover oper-
ates is also selectable between VOX
(for SSB only) and either fast or slow
for QSK (full break-in) CW operation.
This latter feature is one of the main
reasons that someone will purchase a Corsair. It has excellent CW faci-
lities in terms of break-in and is
operative for full listen -through when set to 'fast' up to speeds as fast as I could key it. The RF changeover circuit is essentially solid state using
PIN diodes to handle the 100W of RF,
thus being very fast and silent -
well almost silent as there is a relay
which clicks (quietly) over when you
first key and drops back a short while
after you stop. Its presence is a refinement from Ten Tec and dis-
connects the PA from the antenna during receive to make sure that no noise from the biased -off PA can get through to the receiver. Normally the PA is left connected with volts on it but biased -off so that it presents a high impedance state and doesn't load the antenna. An additional control is that for the audio filter which alters the skirt selectivity. When fully screwed in, it has a narrow bandwidth around 200Hz centred on 750Hz, and skirts of 24dB/octave.
Performance
To review the Mkll it is necessary
to repeat much of what was said about the Mkl, especially the fact that it boasts a plain ordinary down-
to-earth mixer type VFO system. No digital synthesiser here, so why do I say boast?
Well, if performance is what you are after (and on receive one major aspect is the ability to copy weak signals) then you avoid the digital synthesiser like the plague! The only reason I can see why the Japanese like them so much is a) that they are
cheaper to mass-produce than
mechanically orientated VFO's and b) that they can be used to offer memory/scanning facilities with little
10.....
Internal view from above.
problem. Unfortunately, the average digitally synthesised VFO also mass-
produces noises which will mask weak signals, and inflicts other side effects on the receive performance. These effects are often quite plainly audible when you listen to a CW
signal which has been modulated by the phase and amplitude noise from the synthesiser. The effectiveness of the crystal filters is also reduced with the skirt selectivity appearing to be worse.
With a mixer type VFO these effects are very much reduced and where time and trouble has been taken during design to keep phase noise low on the variable oscillator,
superb results are obtainable, achieving very clean mixer oscillator injection. This is the case with the Corsair and the results are immediately plain
when you listen to the superbly
clean CW reception that is obtained. The VFO itself covers 5-5.5MHz
and it is this which determines the overall stability of the rig. Rather than using the conventional capacitive tuning, it is instead permeability tuned, where the inductance is varied rather than the capacity of the circuit. The VFO output is mixed with an appropriate crystal oscillator to generate a frequency either 9MHz
.0111111
I 6*
HAM RADIO TODAY JANUARY 1987
please mention HRT when replying to advertisements. 73G4NXV
45
IF options
Underside view.
above or below the wanted fre-
quency. Each output from the mixer/ VFO module is filtered by bandpass
circuits to remove the unwanted mixer products, except on 20m where the VFO output is used directly with 9MHz to give
14-14.5MHz. The stability of the free running VFO is very good and given a 30 minute warm-up period stayed
well within +/-100Hz at any time.
Sensitivity and Filtering
Switched bandpass filters are used at the front end for each band
before the signal is passed to the RF
input circuits. Depending on the front panel switch setting, signals
are then either passed through an RF amplifier or via a resistive attenuator
using PIN diode switching. The manual gives the sensitivity as 0.25uV for 10dB S/N +N with the
amplifier in and 0.8uV with it out. For
most applications with a decent
antenna system, the RF preamplifier can be left out of circuit up to about 20m, but above this the preamp will
probably be needed. The best
dynamic range will of course occur with the preamplifier switched out and this was measured at 94dB for two-tone at 100kHz spacing (slightly better than the Mkl measured by the same method). This is a good result and indicates that the Corsair is unlikely to give problems arising from
strong signals causing in -band inter modulation products.
The first IF filter is at 9MHz and is used for both transmit and receive paths in conjunction with a bi-directional amplifier. This filter sets the overall bandwidth of the system and acts basically as a roofing filter as it is followed later by further (narrower) filtering if required, depending on the mode. The bandwidth at the first IF is 2.4kHz from an 8 -pole unit (the Corsair I had a standard 4 -pole unit with an 8 -pole option) which also sets the transmit bandwidth of the low level SSB signal.
Noise blanker
Following the filter, we move on to the noise blanker. This is a modi-
fied unit over the Mkl and has
variable width now as well as level settings. With the width control 'off', it is fixed at 400uS and this can be varied up to 5mS if needed, mainly for 'Woodpecker' type interference.
There is a clever bit of circuitry
which, when longer pulses are selected, only allows one such pulse every
80-100mS thus preventing lots of 'holes' in the received signal. As it happens, this is also the repetition rate of the Russian Woodpecker signals. The level at which the interference pulse will initiate the blanking action is set by the level control.
The main IF selectivity at 6.3MHz uses up to four further narrowband crystal filters. This rig
had all the optional filters fitted, but
a single 2.4kHz 8 -pole unit for SSB and CW is supplied as standard. The options are 1.8, 0.5 and 0.25kHz
bandwidths, all of which are
selected by PIN diode switching from the 'Xtal' switch on the front panel. Which set of filters you get (assum-
ing they have all been fitted) depends
on the mode, with the three widest ones in use for SSB and the three narrowest for CW. These filters are not of the hermetically sealed type
you get from Yaesu for example, but
are built up on small PCB's from individual crystals and cost about £52 for each complete filter unit.
Used in conjunction with the various filters is the 'passband
tuning' facility whereby a front panel
control adjusts the position of one of the second IF filters with respect to the fixed -position of first IF filter. With the wider SSB filters you effectively get variable bandwidth as the
filters overlap, and this can be done on the high or low side of the signal.
It becomes more difficult to use with
the narrow filters and you have to re tune using the IRT control to peak the signal in the centre of the pass -
band. The main IF PCB handles most
of the receive functions including RF gain, notch and bandpass facilities,
AGC and S -meter plus the transmit sidetone. Most of the RF circuitry is
based on discrete semi -conductors with IC's for the AF side. This does
mean that the RF part can be designed to do exactly what the
designer wanted, rather than what the chip manufacturer thought he would want!
The AGC system is audio derived
(as with SSB there is no carrier to provide a reference for the gain
controlling circuits and uses a 'hang' type generator. Those of you who have played with the Plessey chips such as the SL1621 will know that this system is very effective for SSB
and CW use, although some people hate it! What it does is to provide a
very rapid attack control voltage
which will hang at the same level for
about two seconds after the signal goes. If no signal reappears during this time then the AGC decays to zero in a few milliseconds, bringing
46
please mention HRT when replying to advertisements. 73 G4NXV
HAM RADIO TODAY JANUARY 1987
back full receiver gain immediately. It has the major advantage of remov-
ing noise bursts during speech
pauses and to some extent also acts as a noise limiter. The decay time can be altered from the front panel to only 0.2 secs if a fast release is
wanted. The S -meter derives its drive voltage from the AGC loop and is calibrated from S1 to S9+ 40dB
with S9 set at the standard of
50uV pd.
Spurii Any receiving system using mixers will generate unwanted signals which become audible as
sproggies when tuning around with no antenna connected. The manual actually lists the major ones where these are greater than 10dB S+N/N
which occur at 1.838, 21.3 and 28.98MHz. There are of course
others but none were found at levels greater than the minimum specified.
Transmit
No microphone is supplied with the Corsair and a Shure 444 was used for this review (directly plugging into the 4 -pin socket). Various microphones are available from KW ranging in price from 25-£38. You can use either PTT or VOX, with the latter having the usual adjustments now fitted on the rear panel. The VOX is very quiet in action of course
with only the sound of the small
relay mentioned earlier. The Corsair
features an audio -type clipper/ compressor processor with a front
panel level control, used in conjunction with a calibration level on the S meter. It works quite effectively in practice.
Rear view.
The transmit signal is generated quite conventionally firstly as DSB,
then filtered to SSB at 9MHz in the bi-directional first filter and thence
up to signal frequency. A driver stage
gives low level RF, controlled by the ALC system, and then amplified up to a final level of 200W input by a pair of MRF458's in the RF power
amp. The ALC control voltage is
derived from the SWR sensing board
and fed back to a diode attentuator
on the input to the low level RF stages. In use, the drive level is
adjusted until the ALC LED just lights
on peaks, or on key -down on CW (for
full power operation). The ALC control sets the threshold for operation - fully clockwise allows full power while fully anticlockwise re-
duces maximum ALC limited power to about 80W. A bank of switched low pass filters removes harmonics
before RF power passes to the antenna via the PIN diode switch
already mentioned. A few other controls not men-
tioned so far - 'Lock' puts the
transceiver into transmit for check-
ing SWR, tuning up etc, in conjunction with the built-in Power/SWR
meter forward and reflected calibrations on the S -meter. The notch filter functions at audio
frequencies and allows a steep notch
of some 50dB to be placed any= where within the audio passband
with very little practical effect on the
intelligibility of speech. On CW, heterodynes are easily reduced to very low or non-existent levels. There is a slight rearrangement of the rear panel over the Mkl, besides the re-
positioned VOX controls, the neces-
sary sockets for the optional keyer paddle have also been provided.
Power supply
This review model came with the matching Model 260 PSU but it can of course be used with an external PSU capable of providing upwards of 18 amps at 13.8v DC. Although the actual transceiver has
ALC as a method of preventing over-
driving, such a feature does not cater
for all possible conditions which could cause the output devices to take more current than is good for
them. Load conditions exist (such as
a highly reactive antenna which
cannot be made to absorb much RF power) which can grossly overload the PA transistors current capability and cause their early demise. The only protection against this problem is to provide a current trip feature in
the PSU itself which will remove
power immediately excess current is detected.
The Model 260 has a built-in breaker circuit and KW can also
supply the Model 1140 circuit
breaker separately for use with an
external PSU (priced at around £15) - if you value your PA devices then this is highly recommended for some peace of mind. The matching PSU comes in an identical style case to the Corsair itself and with a built-in
speaker. Using this disables the
internal Corsair speaker - it doesn't
sound a lot different but has the advantage that it faces you rather than the sound coming via the
louvres on the side and underside of the main rig.
Keyer
The optional keyer paddle (type KR1B priced at £52) is of the twin paddle type, housed in a smallish matching case. I am not overfond of the paddle design but it does work OK in practice. It also has a short memory feature capable of storing up to about 40 characters, operated by a slide switch on the keyer unit front paddle. It is perfectly feasible to use another paddle if you want, together with the memory feature, as instructions are given on how it operates in the manual. The nominal
speed range is 8 to 50 wpm
although this version only went up to about 32 wpm in practice. The keyer speed is set on the Corsair front panel although the speed setting is very compressed with most of the change happening over
ID
HAM RADIO TODAY JANUARY 1987
please mention HRT when replying to advertisements. 73G4NXV
47
about the top third or quarter of its travel.
The key is unusual in that the pressure is controlled by small solenoids pulling against each paddle, with a pot on the rear which varies the current and thus the pressure. To be quite honest, I didn't like the paddle 'feel' but others might. It
tends to be noisy in operation especi-
ally if you have the paddle pressure set high.
The memory function is good for calling CQ but has one nasty little feature. Without instructions to the contrary, the only way to initiate it after a recording had been made was
to quickly flip the program/send
switch to 'program' and back again. This sends the memory contents, but if you leave it in the 'program' setting for a little too long, it assumes you are going to program it again and the memory disappears!
In use
Like the Mkl, the rig was used over a period of eight weeks on both SSB and CW on most bands where there was some activity. Again, no problems were encountered and complimentary reports were received on the SSB quality. Not surprising since at full power the 3rd
order IMD products are some 40dB down on peak power, good by any standards. The QSK facility was a joy to use and the full complement of filters in conjunction with the PBT and notch filters made disposal of QRM very easy. If you can't afford the narrow CW filter options, the variable skirt selectivity audio filter is very effective on CW and can be
used with some limitations on SSB. It doesn't of course have the skirt rejection of a crystal filter but is still
a lot of help. You can also play
around with the selectivity using the PBT in the absence of the narrow filters.
The Noise Blanker is rather more
The Model 260 PSU
effective than the original version and coped very well with all the
normal impulse interference on 80m
with the width at minimum. The
Woodpecker seemed to be having a holiday whenever I was on so I can't
comment on its effectiveness
directly. However, a test pulse gener-
ator used to simulate the Woodpecker was blanked very well so it should work on the real thing.
All the other features did as
required and I can't really say much
more than that. The receive performance is very good, clean and free from IMD problems even on 40m for the reasons already explained. Sen-
sitivity was better than 0.25uV for 10dB S+N/N on all bands. The manual is excellent and contains
plenty of photographs, check voltages, circuits and alignment instructions, together with copious notes on operation and how to get the best out of the rig. Obviously written by experienced amateurs who know what you will want to know.
Conclusions
As a rig primarily for the CW
operator it can be highly recommended and has very good SSB capability as well. You may consider that its price is high for what you get in facilities and appearance compared with a Japanese black box but you will have to offset this against the performance and a different country of origin. Perhaps anyone considering a purchase ought to convince themselves by either paying a visit to KW and getting hands on experi-
ence, or finding someone with a
Corsair who will let them play with it. The standard Corsair Mk II costs
£1147.22 and the PSU costs
£203.09 - a total price of £1350.31 including VAT and delivery.
Corsair Mkll - front view with PSU.
Thanks are due to KW Commu-
nications for the loan of the Corsair
.M1111...36
and its accessories.
48
please mention HRT when replying to advertisements. 73 G4NXV
HAM RADIO TODAY JANUARY 1987
Igoo
(03.g7
In the mid 1970s, the rig in my shack
was the well known FT200. This was generally quite an effective
piece of equipment, but as the main mode of operation at GM3HBT has
always been CW on the HF bands,
the lack of a narrow CW filter in the
into service. This op -amp filter made
an enormous difference to reception of CW, but in experimenting with it
the following facts became evident:
(1) The filter had 4 switchable stages, providing bandwidths of approximately 180, 120, 95, and
A cheap and effective alternative to crystal IF filters for CW from Tom Hall, GM3HBT.
IF circuit was a noticeable drawback
and with the FT200 there was no option for adding one.
CW Audio Filters
However, at that time a reasonably priced audio filter was
available by MFJ, which was normally intended to be fitted
between the rig and the speaker so one of these was purchased and put
85Hz. In use, it became clear that, for me at any rate, the setting which was by far the most effective for all normal operating was a bandwidth of 120Hz, ie two stages of filtering. (2) Although the MFJ worked well
between the rig and speaker, I found that the optimum position appeared
to be achieved when it was inserted at the top end of the volume control.
(3) The only operating condition which the filter could not cope with
effectively was when there was a strong adjacent signal within the IF passband (2.4kHz). Even when that
signal was not itself audible through the filter, it had the effect of acting
on the AGC to suppress the received
signal in sympathy with the
offending adjacent signal, thus making reading the CW somewhat difficult.
Since those days, I have used the TS5205, TS5305, FT77 and now a
Corsair, all of which have had a
facility for fitting an optional narrow 500Hz CW IF filter which, in each case, had been fitted. Remembering my success with the MFJ (which had been sold with the FT200), I built a little two -stage switchable op amp filter on a scrap of Veroboard
and added it first of all to the
TS520S, which when used together with the narrow CW filter gave quite
superb results. So much so that each
C2
Cl
R1
C3
IN
R3
7
01
4
C4
ci
R4 R6
R
C5
2
7
Q2
4
R7 R8
'C7
COMPONENTS
R1,4 = 390k %W
Cl = 100n MYLAR
R2,5 = 820k %W
C2,3,4,5 = 2n2 POLYSTYRENE
R3,6 = 12k 1/4W
C6 = 1u0 TANT
R7,8 = 15k '4W
C7 = 4u7 16V
Q1,2 = 741 OP -AMP
Fig. 1 Circuit diagram of the CW audio filter
O+Rx 9-15V
AP. OUT
0 -Rx
HAM RADIO TODAY JANUARY 1987
please mention HRT when replying to advertisements. 73G4NXV
49
rig since has had my little homebrew filter fitted, not to mention an R1000, and FT7700 and the rigs of several
friends, all of whom have been
delighted by the results. I suppose a little pcb could be designed for the filter, but it is so easy to fit on a small piece of Veroboard that I never took the trouble to do so.
The Circuit
The circuit of the filter is shown in Fig. 1 and the method of inserting it into the audio circuit of a rig in Fig. 2. If the components are taken
from normal 5% tolerance stock, the
results are very good, but if you have access to measuring equipment and can select R and C values so that there is a closer match between the
stages, then so much the better. The
formula which gives the centre
frequency is:
1000 fc = 21TC
R1+R3 R1xR2xR3 Hz
Where resistance is in kilohms
and capacitance in microfarads. With the values shown, this is 740Hz. If you are a purist, then slight variation of the value of R3/R6 will result in a filter frequency which is exactly the
same as the rig sidetone - I have even made R3/R6 miniature pots to achieve this and find it a useful touch. The bandwidth is around
120Hz.
The circuit is built on a small piece of Veroboard, about 2.25" by 1.25". No layout is shown, as constructors
usually have their own favourite
methods of using Veroboard.
Fitting the Circuit
The completed module can be
IN
OUT
DISCONNECT ! ORIGINAL I
WIRING HERE
RIG VOL CONTROL
SW1
F = CIRUIT OF FIG.1 SW1 = SPCO TOGGLE SWITCH
Fig. 2 How to add the filter to an existing rig
fitted in any convenient small space inside the rig. I always use double -
sided sitcky pads for this, which
means that if subsequently deciding to sell the rig it may be returned to the as new condition without leaving
tell -tale holes. By doing this the
wiring can be easily returned to the
original, unless of course the
purchaser is so impressed that they want to keep the filter in!
I have nearly always been able to use a redundant front panel switch (eg an unused CAL button) to switch the filter in and out of circuit, if not then a little toggle switch fitted on the rear panel can be used. Wiring to the audio stages and switch should be in miniature screened audio cable and the unit can be connected into the nearest RX positive voltage point in the circuit.
Further Uses
Like many others, I have recently
built the neat little Howes DcRx
receiver for a QRP transceiver. This
has, in common with all DC
receivers, a not too spectacular selectivity, but with the addition of
a two/three stage filter as described
(switched to provide 'wide and nar-
row' selectivity), I have been delighted by the results. This
modification can be made by
removing the original connection
between the junction of R12/C13 and
the top end of VR1, then inserting a two/three stage filter as shown in Fig. 3. The DcRx now has virtually
the feel of a superhet - another
worthwhile project! I think it is a pity that very few
commercial rigs have the facility for
optional audio filters, when they can
make such a decided improvement in
listening to CW even when a narrow
CW filter is fitted. I am sure that anyone who is prepared to spend
under £2.00 on components and an
hour or two building and fitting this
simple unit will be more than
satisfied with the results. I am sure that you will find the reception of CW all the more pleasurable for
having done so.
DCRX CIRCUIT
JUNCTION R12/C13
>---I 0>
'WIDE'
1u0
1TANT
> 1u0 'NARROW' T+ANT
ow
SPCO SWITCH
'TOP END' OF RV1 NOTE: 01.23 = 3 FILTER STAGES AS IN FIG.1
Fig. 3 Adding the filter to a Howes DcRx transceiver
50
please mention HRT when replying to advertisements. 73 G4NXV
HAM RADIO TODAY JANUARY 1987
ul RgaoDGuDndupx,T
Quartz crystals may be as old as the
hills but they utilise state-of-the-art technology in their manufacture. They are widely used in amateur
radio as frequency determining
reliable and often find many uses based on these factors alone.
How do they Work?
Quartz exhibits what is known as
What's up to the minute yet as old as the hills? Ian
Poole, G3YWX, introduces some rather useful bits
of old rock.
elements in oscillators or filters and as their technology advances they are able to meet the more exacting
requirements placed on them.
Crystals with better specifications, higher values of Q, higher operating frequencies and lower ageing rates are now being produced. In addition to this the average cost per crystal is falling both in real terms and actual cost.
What is Quartz?
Quartz is a form of silicon dioxide
which has crystalised into a
hexagonal structure. Although silicon dioxide is the most common mineral on earth, it is found only rarely in the form of quartz. As quartz, it is a unique mineral exhibiting all the properties required to enable it to be used for frequency control or filtering.
Why Use Crystals?
Crystals are widely used because
they exhibit a combination of
properties required by frequency determining components. They possess exceedingly high values of Q often around and sometimes as high as 100,000, values which are unheard of for any other form of
resonator. This gives them an
extremely good performance when used in filters enabling them to surpass other components in terms of performance. They also exhibit very high degrees of stability with respect to temperature and time,
making them very useful 'as
resonators in oscillators. In addition
to this they are both cheap and
the piezo electric effect which
means that any mechanical stress applied to the crystal will cause a voltage to appear at its plates and likewise any voltage applied will create mechanical stress. The crystal
is cut so that mechanical resonances occur within it at precise frequencies
and these are translated to the electric circuit by using the piezo
electric effect. Therfore the crystal
can be made to become a high
quality electric resonator suitable for a variety of applications.
Crystal Manufacture
The way in which a crystal is made will determine many of its
characteristics. Therefore careful manufacture and the use of accu-
rately controlled processes is essential. Here, up to date
technology has produced dividends in improving both performance and the ease of manufacture.
The first stage is to cut a round
blank from the right grade of
specially cultured quartz. The correct
orientation of the crystal lattice
within the blank is essential as this will determine factors including the mode of oscillation and temperature stability. The most common orientation or cut is known as the AT cut which is used because it gives optimum temperature stability for most applications.
Once the blank has been produced it then has to be lapped to
the correct thickness as this
determines the crystal's resonant
frequency. The lapping is done using
a very fine paste so that an
extremely good finish is given.
However, even after lapping the surface is still not smooth enough due to discontinuities in the crystal
lattice which cause ageing and loss of activity. Therefore the blank is
chemically etched to give the
required finish.
The crystal then has to be
mounted both mechanically and electrically. This involves creating electrodes which are made by depositing silver or gold onto the
crystal surfaces. In fact the mass of the electrodes can be used to trim
the frequency of the crystal to
exactly what is required. All that then remains is to bond
the crystal to its mount. This is done in such a way as to keep losses to a minimum, thereby ensuring the highest value of Q. The crystal is placed in its holder which is then
either evacuated or filled with an inert gas to prevent any chemical activity with the edge of the crystal lattice which causes ageing.
Current Applications
Crystals are still used in great
numbers despite the fact that
synthesisers are almost universally used in VHF transceivers and sets
with banks of crystals are considered to be rather 'old hat'.
Nevertheless crystals are essential in
order to generate the reference frequency signals for synthesisers and they are also widely used in
fixed frequency RF oscillators as well as in microprocessor clock oscillators and a host of other applications.
In view of their cost and performance they will undoubtedly still be in
general use for many years to come.
HAM RADIO TODAY JANUARY 1987
please mention HRT when replying to advertisements. 73G4NXV
51
If you are into DXing you may find that offering your receiver a Beverage will help you reach parts other aerials cannot reach. As well as the 'Tropical
Bands; our eavesdropper visits Latin America, the Caribbean and the States - on medium wave!
So far in this series of articles, I have concentrated on what the average listener can hear in the way of broadcast stations on a fairly simple communications receiver, or without sophisticated antennas. By the time this is read though, we will be in the depths of winter and so this month we will look at DXing for broadcast stations on the LF bands, by which I mean the so-called 'Tropical Bands' at roughly 60, 90 and 120 metres as well as long and medium wave.
Do you have a suitable receiver?
highly praised, the CR100 and the B40.
Antennas for life
As far as antennas for the tropical bands are concerned, a
random length long wire will usually suffice, though if you get hooked on the bug of tropical bands DXing I would recommend something a little better. A half -wave dipole for the 60
metre band (cut for 4.8MHz -
roughly the middle of the band) is about 97 feet long and should give
very good results. A half -wave dipole
If you have a transistor portable
receiver covering these frequencies
you may hear one or two of the stronger stations, such as 'Africa
Number 1' in the 60 metre band, but without a reasonable quality communications receiver you will largely
be wasting your time trying to find
real DX stations on these fre-
quencies. Even the present range of amateur transceivers with general -
coverage receivers such as the Yaesu
FT757 or Trio TS430S, while excellent on short wave, tend to be very insensitive on frequencies below 1.8MHz. I used an ex -government communications receiver called an R206 for a number of years with excellent results on the LF bands
though it was very unstable on frequencies above about 14MHz! I
know a number of people who have had equally good results with such ancient receivers as the AR88, the AR88LF version being particularly
for the middle of the medium -wave band however, would be well over 500 feet long and is therefore clearly impractical! Again, a random -length long wire can be used on medium wave, though in this case a good ATU is a must as the wire will almost certainly be very short in terms of wavelength.
There are two main types of
specialist antennas used by medium wave DXers, both of which are direc-
tional. The first is the Beverage which also requires a lot of space. The theory books will tell you that
for a Beverage to work well it should be several wavelengths long, but in practice quite good results can be obtained from Beverages of only one half wavelength. For the middle of the medium wave, this still means they should be about 150 metres in length and this should be regarded
as a minimum. However the big
advantage over a half -wave dipole is that the Beverage works best when at a low height, typically about 8 to 12 feet above the ground. A dipole should be at least a half -wave high,
or about 500 feet, again clearly impractical! It is often possible to string out several hundred feet of
Rarities on the 60m band include Malaysian stations, but Papua New
Guinea is probably amongst the rarest
to be found in this area.
52
please mention HRT when replying to advertisements. 73 G4NXV
HAM RADIO TODAY JANUARY 1987
wire along the top of a wall or fence or even through trees where it would not be possible to put up a long wire
'in the clear, as long as the wire itself is insulated this doesn't matter. The Beverage is directional off the end of
the wire if terminated, or is bi-
directional along the axis of the wire if un-terminated. This statement is
very approximate and in fact for
Beverages which are short in terms of wavelength there are several lobes on either side. The impedance is typically several hundred ohms, so some sort of matching transformer is required if your receiver has a 50ohm input. The big advantage of the Beverage is that it is a very quiet antenna; static crashes which can be very loud on medium wave on other antennas are largely attenuated on the Beverage.
The second 'specialist' medium wave antenna and more practical for most people, is the frame or loop antenna. This consists of about 7 or 8 turns of wire on a three or four foot square wooden or plastic frame (or about 16 to 18 turns on a two foot square frame) tuned with a 400 or 500pF variable capacitor. Some experimentation will probably be required but given suitable values, it is possible to get the antenna to work and be resonant over the whole of the medium wave. It should be constructed on a stand so that the loop can be made rotatable, or it can be put on a rotator out of doors. The frame antenna is largely omnidirectional but has two very deep nulls, so it is used to null out inter-
ference rather than peak up the required signal. It works best of
course, when the interfering station and the station you wish to receive are at 90° to each other, but since the nulls are very sharp it can be made to differentiate between two stations co -channel with each other even when they are coming from almost the same direction (eg two North American stations in different states).
'Tropical' DXing in the winter months
To go back briefly to the tropical bands, DXing on these bands can be rewarding at any time of year. In the
summer for instance, very good
signals are often received in the late evening from African stations and from South American countries in the early morning, though both are often marred by high levels of static. It is generally only possible to receive stations in the Far East and Pacific area on these bands in the winter months, though. The main reason for
I ilimommiou
Noose Accept %es en Yew Confirm* el Yew Reeption fon W Time. 11.kni, Yoo for Li*, CHIEF NG NE
A
vE. TIUS ARMES IOU LISTENED 10; CHICAGO, ILLINOIS U.S.A.
1.000 tat 50 KW 0/4
Dowsers Drat Pi,
thanks Far IOW Report!. 73's
wt.
WiRraCIICA Ac:ITVAVINiscowWww...woms.
kosiN0 5T/1/4110N
ANtERASKGREAT
50.000 Watu
ye., tepee *PO.
11,111,
Yaw wooe
Spectacular medium wave DX is
possible during sunspot minimum as these QSLs show - in the past, even
Californian stations have been
confirmed in Southern England.
this is that it is necessary to have a darkness path between the transmitter and receiver on these frequencies and these conditions only
occur for a few months in the
northern hemisphere winter. The time to listen for Far Eastern and Pacific stations is at the time of so-
called grey -line propagation, ie from about an hour before local sunset until an hour after, and again around local dawn. In practice a good time is around 1600 GMT in the early and
late winter and as early as 1330
GMT in mid -winter. One of the best -received
stations from this area is Radio
Singapore on 5052kHz, which also
has the advantage that its pro-
grammes are in English, they sign -off
for the day with the Singapore national anthem just after 1600
GMT. For a number of years Radio Singapore has also been testing a second transmitter on 5010kHz, sometimes in parallel with 5052kHz, and this can be a useful check to be certain that it is Radio Singapore that you are listening to. There are several stations from Malaysia on the 60 metre band too: their English service is on 4985kHz from a 10kW transmitter at Penang which also signs -
off at 1600 GMT. If you are very lucky you may also hear Radio Malaysia's service in English from Kota Kinabalu, Sabah, in East Malaysia on 4970kHz, but this one
is very rare! Other English -language
HAM RADIO TODAY JANUARY 1987
please mention HRT when replying to advertisements. 73G4NXV
53
stations from this area are the
National 'Broadcasting Commission of Papua New Guinea (programmes
are in Pidgin English as well as more
standard English!) which is on
RADIO SRS soum AMEN FOUNDATION SURINAM 1120A6CASTIN6
AM 725 1CCS -SO IKW .FMFQTicTtuMvoCmbSoEdeSe0. 110fb/144
4890kHz, but note that they sign -off
at 1400 GMT. So it is a very rare
catch indeed and only really possible
for about a month around mid-
winter.
Finally, Australia has a frequency in the 60 metre band which it uses
for domestic broadcasting on
50kW can go a long way, but a frequency change by Radio SRS, Surinam to
4920kHz. Unlike the others men- 600kHz has made this already difficult station even more of a catch.
tioned so far, this one is more usually received in Britain in the early mornings, via long -path reception -
try around 0700 or 0800 GMT if conditions are very good. This frequency is a relay of Brisbane's
local radio service, presumably intended for the sheep -farmers in the outback of Queensland and it can be quite a thrill to hear local news about Brisbane, or what is on at the local cinema from such a vast distance!
DXing down on medium wave
On medium wave, arguably the most interesting target for DXing is North America. Canadian and USA stations can be found every 10kHz on the medium wave, from 540kHz to 1600kHz. They are therefore generally on different frequencies from their European counterparts, which are on frequencies that are exact multiples of 9kHz. So with a receiver having good selectivity, it is often possible to receive North American stations reasonably in the clear, depending on the frequency. For example, one of the most con-
sistently well -received North
American stations in Britain is CJYQ in St John's, Newfoundland, on 930kHz. It is comparatively well received for several reasons, firstly Newfoundland is the closest part of
the North American continent to Britain, but perhaps more importantly it is 3kHz away from the
nearest European stations, which are
on 927kHz. On the other side of
Britain, even when nulled out on a loop antenna. However, after the Dutch station closes down for the night, WINS can often be heard at good strength. Their format is 'all news, all the time' with plenty of adverts and station IDs (identifications). As on all frequency bands, conditions can vary considerably
from one day to the next. A good rule
of thumb is that if CJYQ is weak and watery by 2330 GMT, forget it, get a good night's sleep and try again the next night!
At the bottom of the sunspot cycle, ie around now, some fairly spectacular DX is possible on the medium wave. At least two Californian medium wave broadcast stations were heard in southern England during the last sunspot
minimum, and some people have the
QSLs to prove it. If you're lucky enough to be DXing on a night of good conditions, when there seems to be an American -sounding voice
every 10kHz along the dial, here are
some stations to look for: WSM, Nashville, Tennessee, on 650kHz;
WJR, Detroit, Michigan, on 760kHz;
WCFL, Chicago, Illinois, on 1000kHz; WOWO, Fort Wayne, Indiana, on 1190kHz and WOAI, San Antonio, Texas, on 1200kHz.
None of these stations will be there every day, indeed some may only be audible for one or two days a year in Britain, but if conditions are
good they should be audible at least
occasionally, and they are a lot more distant than the run-of-the-mill east coast stations.
Canada, the chances are it is Radio Monte Carlo in Montevideo, Uruguay, although beware: the lower -power
Radio Maracay in Venezuela is on the
same frequency! Yet another station also on 930kHz which sometimes
makes an appearance in Europe is Radio Antilles, a 300kW commercial
station on the island of Montserrat.
This broadcasts in several languages,
including English and French and it also relays BBC World Service and Radio Canada International programmes for the Caribbean area. Despite being much higher power than the other stations on the same frequency it is only rarely heard in Europe. Which stations are audible on any given night depends on the prevailing propagation conditions, although with a good loop antenna it is sometimes possible to differ-
entiate between different DX
stations on the same frequency.
Finally, two other stations in the Caribbean area deserve a mention, as they present quite a challenge to
the medium wave DXer. Firstly, Radio
Paradise on the island of St Kitts, which broadcasts mainly religious programmes in English, used to be
very frequently heard in Britain when it was on 1265kHz, despite strong interference from the Deutschland funk transmitter on 1269kHz. Now
however, Radio Paradise is on 825kHz and it is far less frequently logged. Another station that changed frequency, this time from 725kHz to 600kHz, is Radio SRS in
Surinam. This was a difficult station to hear at the best of times, but now
CJYQ the Europeans are on 936kHz.
CJYQ is generally the first North American station to fade-in in the
it is on the same frequency as more
Some Latin American and powerful Brazilian and Colombian
Caribbean stations
stations.
evening: the earliest I have heard it
I hope this introduction to DXing
is around 1930 GMT in the middle of
winter one year, although a far more
likely time is from about 2130 or 2200 onwards.
One of the best -received stations from the USA is WINS in
Sometimes, when conditions are
not particularly good for North
America, a number of South Ameri-
can stations can be heard. It is quite
easy to log stations in Brazil (especi-
ally), Venezuela and Colombia,
for broadcast stations on the lower frequency bands has inspired a few people to have a go at this fascinating aspect of the hobby. You can learn a lot about propagation and
also get quite a thrill out of listening
New York, on 1010kHz. The main problem here is interference from the Dutch station on 1008kHz, which is extremely strong in most parts of
though some of the other South American countries are a bit more tricky. If you hear Spanish on
930kHz though, instead of CJYQ in
to stations thousands of miles away which are broadcasting only to a
local audience. Good luck and good listening!
54
please mention HRT when replying to advertisements. 73 G4NXV
HAM RADIO TODAY JANUARY 1987
Your at -a -glance guide to what's happening around the clubs, on the air and in general radio -wise.
1 Dec
2 Dec
3 Dec 4 Dec 5 Dec 8 Dec 9 Dec
10 Dec 11 Dec
Basingstoke ARC: Clandestine Radio, by
G 3VA.
Felixstowe DARS: Computer evening. Welwyn Hatfield ARC: AGM. Braintree ARS: Film Show. Central Lancashire ARC: Xmas junk sale and AFS 2m contest planning. Todmorden DARS: Social with talk by George Dobbs (mems only). Worcester DARC: Talk on RAYNET. Worksop ARS: junk sale. E. Lancashire ARC: AGM. Fylde ARS: equipment construction competition. Wakefield DRS: On the air. Warrington ARC: Talk "Chirpsound and frequency management" by CPO McDonald of
HMS Inskip. Fareham DARC: Talk "Decoding Morse With A
Micro" by G6TJT. Spen Valley ARS: The Breathalyser(!) N. Bristol ARC: Natter night and Committee
Meeting. S. Lakeland ARS: Film show. Horsham ARC: AGM. Shefford DARS: Constructors Contest. Maltby ARS: activity night on air. Dunstable Downs RC: Junk sale. Coventry ARS: Talk "All about RAYNET". Harrow RS: Activity Night. Southdown ARS: AGM. Milton Keynes DARC: Radio and Radar Navigation Aids. Sheffield ARC: Christmas Social. S. Cheshire ARS: Annual Social. Dartford Heath DFC: Pre -hunt meeting. Midland ARS: Christmas Party. Chester DRS: Your Questions Answered. Wakefield DRS: Mastermind Quiz. Warrington ARC: Talk "Computer Security", by
G3NFB.
Verulam ARC: Activity Night. Dunstable Downs RC: Junk Sale. Crawley ARC: Fish & Chip Supper. Stockport RS: AGM. Chiltern ARC: Xmas Party. Trowbridge DARC: Main Meeting. N. Wakefield RC: On the air. Edgware DRS: Grand Junk Sale. Pontefract ADARS: Video, Visit to China.
12 Dec 13 Dec 14 Dec 15 Dec
16 Dec
17 Dec
18 Dec 19 Dec 23 Dec
Bredhurst RTS: Talk "An HF Vertical" by Mac,
G3ZHZ. Southgate ARC: AGM. Maltby ARS: A direct conversion receiver for 80m. N. Bristol ARC: Region 20 rep visit. Coventry ARS: Night on air. Three Counties ARC: Christmas Party. Dartford Heath DFC: DF Hunt. Milton Keynes DARS: Long Range Navigational Aids (USAF). Felixstowe DARS: Family Social. Welwyn Hatfield ARC: Christmas Social. Braintree ARS: Christmas Social. Worcester DARC: Xmas Skittles Night. Pontefract DARS: Club Party Night. Stourbridge DARS: Talk "QPR Kits" by G3ZOM. Braintree ARS: Christmas Party. Worksop ARS: Computer Night. Dartford Heath DFC: EGM at the Horse &
Groom. Biggin Hill ARC: Christmas Dinner. Chester DRS: Construction Contest. Wakefield DRS: Bermuda by G4JMT. Chichester DARC: Christmas Social. Fylde ARS: Hot Pot Supper. Verulam ARC: AGM. Warrington ARC: Open Forum. Hastings ERC: Christmas Social. Fareham DARC: Lecture "VSWR Facts and Fallacies".
Burton Upon Trent DRS: DF. Cheshunt & District ARS: Cheese & Wine & Video Evening. South DARC: Test Gear Demo. SE Kent (YMCA) ARC: Christmas Social. Bredhurst RTS: Christmas "booze -up". Solihull ARS: Christmas Social. Spen Valley ARS: Anti -Christmas Anti -Social. S. Lakeland ARS: Christmas Night Out. Shefford DARS: Chairman's Social. N. Wakefield RC: Christmas Dinner. Maltby ARS: Annual junk sale and Xmas buffet. N. Bristol ARC: VHF Activity Night. Coventry ARS: Social at Bull & Butcher. Chester DRS: Christmas Buffet. Wakefield DRS: Christmas Social. Warrington ARC: Social with food.
HAM RADIO TODAY JANUARY 1987
please mention HRT when replying to advertisements. 73G4NXV
55
29 Dec 30 Dec
2 Jan 5 Jan 6 Jan
7 Jan 8 Jan
9 Jan
13 Jan
14 Jan 15 Jan
Felixstowe DARS: Social. Wakefield DRS: On the air. N. Bristol ARS: Xmas Party. Maltby ARS: Activity night on air. N. Bristol ARC: Xmas Party. Todmorden DARS: Construction Competition. Loughborough DARS: Cross band working from home QTH. Fylde ARS: AGM. Warrington ARC: Open Forum. Chester DRS: AGM.
Trowbridge DARC: AGM. Three Counties ARC: Talk "SEB Telecoms" by Steve Frost G4VNM. Pontefract DARS: AGM. Bredhurst RTS: Talk "Antique Sound Recordings" by Colin Johnson of Radio Kent. Horsham ARC: Homebrew Evening; Edgware DRS: AGM. Spen Valley ARS: Rifle Shooting. N. Bristol ARS: Talk (to be arranged). Coventry ARS: The (indoor) direction finding game.
Wimbledon DARS: Social Evening. Maltby ARS: Building a multimode transmitter for top band. N. Bristol: Talk (TBA).
Loughborough DARS: Magazine reviews. Walsop ARS: Duff Xmas Present Sale. Warrington ARC: Talk "All at sea with electronics" by Jim Phillips GW3PRA. Chester DRS: Talk by the winner of the construction contest. Fareham DARC: Morse Testing. Pontefract DARS: Film "The Electronic Mountain".
16 Jan 20 Jan 21 Jan
22 Jan
23 Jan 26 Jan 27 Jan
28 Jan 30 Jan
Coventry ARS: Night on the air. N. Bristol ARC: VHF Night in the morse room.
Loughborough DARS: Forum - Computers in Ham Radio.
Hastings ERC: Talk on British Rail Traction Engines by Brian Cornwall. Fareham DARC: AGM.
Three Counties ARC: Treloar Hospital Radio by Paul Le Feuvre GODBS. Spen Valley ARS: Talk - Development of Sound Recording, by Tom Anderson G6DLA. Pontefract DARS: Annual Junk Sale. Bredhurst RTS: Junk Sale. Coventry ARS: Annual Dinner. Bredhurst RTS: Christmas Dinner/Dance. Maltby ARS: Computers in Amateur Radio. Felixstowe DARS: Visit to Hospital Radio Ipswich.
Loughborough DARS: Construction Evening. Worksop ARS: Talk on home brew solid state, by Bernard, G4SHU. Waterside SWC: TBA. Fareham DARC: Talk "Satellite update" from David, G6XHR. N. Bristol ARS: AGM. Coventry ARS: Night on the Air. Maltby ARS: A simple absorption wavemeter for 144MHz & higher. N. Bristol ARC: AGM.
Will club secretaries please note that the deadline for the February 1987 segment of Radio Tomorrow (covering
radio activities from 1st February to 1st April 1987) is 17th December.
The contacts list will appear next month.
If an advertisement
is wrong we're here
to put it right.
NEXT MONTH
If you see an advertisement in the press, in print, on posters or in the cinema which you find unacceptable, write to us at the address below.
The Advertising Standards Authority.
ASA Ltd, Dept 3 Brook House, Tomngton Place, London WC1E7HN
BINDERS
FOR YOUR VALUABLE COLLECTION
OF HAM RADIO TODAY
I. "Ps
MAGAZINES
£5.20 t
SMART EASY TO USE TOP QUALITY -I inc
1
To ASP Readers Services, PO Box 35, Wolsey House, Wolsey Road, Hemel Hempstead, Hefts HP2 4SS (0442-41221)
% aim°S
I Please supp-""ly". @ £5.20 inc. P&P
Ham R7dri:74di; Binders -
Total ..... (Please make cheques payable to ASP Ltd.) I
I Years Required - 198 198 198 198
FT290 Auto -tone
A multi -mode multi -mod
Desert Island DX
Setting up a DXpedition - even to near shores can be a lot of hard work!
HF Rx Project
Use the winter evenings to build your own all mode multi -band receiver
Famous Names First of an occasional series on the people who
really made radio
Co -ax Aerials For UHF Make robust radiators for 70cm
Note: whilst all the above articles are in an advanced state of preparation, we cannot guarantee they will actually appear due to restrictions on space, etc.
MINIM I
fafVISA
Name Address
Please allow 21 days for delivery
link =I
56
please mention HRT when replying to advertisements. 73 G4NXV
HAM RADIO TODAY JANUARY 1987
z_t_m4itul:,/e9L)2
tul4R7/ P5000(00
A transmitter is of course no use
Don't try plugging the UHF each other, enabling you to fit the
without some method of generating output from the Spectrum into your buffer in the original modulator case,
video signals to transmit, your transmitter, it doesn't work very hence providing a neat set-up.
contacts would of course like some- well! You must tap off the baseband thing to watch wouldn't they? If you video feed to the internal UHF modu-
Cirkit Test Card Generator
own a video recorder and are lucky lator and then feed this to your trans -
If you don't own a suitable
Chris Lorek, G4HCL, rounds off his ATV series
computer or if you would like an
instant test source without the need
with a look at the various options for generating video signals. Take your pick from a purpose built
for program loading each time, the Cirkit test card generator kit has proved popular with many ATVers.
test -card generator, a low-cost camera or a humble microcomputer!
There however are one or two very important points which you should note concerning its construction.
enough to have some home videos to transmit, then by all means make
use of them if the remainder of family approve! Most video
machines give a 1V p/p output plus a separate audio output at the rear. Twisting the arm of a friendly ATV
operator with a camera could set you
up with a small collection of
recorded material or several video rental outlets will hire you a camera for the weekend. Remember the licencing requirements for periodic callsign identification though!
For a 'stand alone' ATV station
there are several methods of video generation, the easiest being the
once -mighty, but now possibly little
used, home computer.
Worthing Group's Spectrum program
mitter via a suitable level setting potentiometer. This has been successfully accomplished by some amateurs, however the Spectrum
circuitry sometimes objects to being
presented with a low impedance
Apart from being impressed at the good packing and instructions that come with the kit, you will not I feel be too impressed when you try
it out! Firstly, there are two wire links
described as being necessary on the board but link 'A is not required and in fact the board will not operate if this is fitted. Secondly, several
amateurs have found that their boards exhibit a 'race' condition between the data latch and multi-
plexer select lines. By delaying the
select line for a few nanoseconds, by
placing a small capacitor of
100-470pF between IC1 pins 12 and
1, you can get over this problem. The
third 'quirk' concerns the width of the sync. pulses and subsequent
positioning of the testcard. The turn-
Sinclair Spectrum Use
load and a small buffer circuit is re- off characteristics of Q2 sometimes quired for correct interfacing. Fig. 1 cause the pulses to be extended,
This is undeniably the most shows a suitable buffer and thanks fitting an 820R resistor (not 180R as
popular home computer with are due to G8DHE for this 'fix'. sometimes recommended) between
amateurs in this country, there is Depending upon your soldering Q2 base and emitter will correct this.
even a specific amateur radio users dexterity, component leads may be
Building the board requires a fine
group for them. Keen program trimmed short directly soldered to tip soldering iron and much patience,
writers will certainly be able to
generate many useful video sources from them. For the remainder of us
who don't relish all night 'bug hunting', the Worthing Video
Repeater Group have produced an
excellent program for the 16K and 48K Spectrums, providing a multi-
FROM VIDEO INPUT TO
MODULATOR
D1
D2
+5V RAIL FROM SPECTRUM
ank BC108 OR EQUIV
NOTE. 01,2 = ANY LOW.CURRENT SILICON DIODE eg 1N4418 or 1N4001 RFC1 = 1 TURN ON FERRITE BEAD
,II-'----oVIDEO OUTPUT
Tho
RFC1
100R
tude of test cards, maps, station
details and so on. These are available
from G8XEU for £6.00
OV
Fig. 1 Video buffer for the Sinclair Spectrum
HAM RADIO TODAY JANUARY 1987
please mention HRT when replying to advertisements. 73G4NXV
57
it took me around two and a half hours to ensure a good job was
made. The end result was worth the
effort though and more than one
23cm repeater is known to be using this board due to the good results obtained. A plug-in Eprom is required to give the final image and this is not supplied with the kit but that enterprising Worthing group can supply a range of eight different styles costing £5.00 each, as well as addon accessories for the unit.
The VK4901 Camera
Now we've got you started, let's move onto making you a TV star. As
The Cirkit test card kit, built up promised in Part 1, here are details
of this little unit which are now
becoming available and look set to
take over from where the 'Lynx'
camera left off. The VK4901 should
be easy to obtain, Astley Video
Services amongst others are already known to have had them for sale at rallies. The camera operates from a 12V supply normally fed via the coax cable and was introduced several years ago to be used in small closed circuit TV security applications. It
has an automatic light sensitivity control (obviating the requirement for an iris adjustment) and operates from 3 to 30,000 Lux, so you won't need floodlights in your shack any
more! It gives a VHF AM modulated output with 6MHz FM intercarrier sound which in itself is of little use, but read on . . .
Inner Workings
To produce the modulated carrier the unit must of course first generate baseband sound and vision, Fig. 2 shows the basic line up. 2V peak to peak video is generated which is fed via an emitter follower to R3140, a
220R potentiometer. The slider of R3140 is connected to the output of the 6MHz intercarrier FM sound generator and is then applied to the VHF modulator via L5160. By removing L5160 and tapping off at the R3140 point we may feed the output to a transmitter and have instant 23cm video combined with inter -
carrier sound. The source impedance
here will be in the order of 50-
100ohms, hence matching reasonably well into most 75ohm video systems including the DC 24 FMS transmitter.
Surplus cameras are normally
preset to 6MHz sound which is the most commonly used standard, but you can tune L5238 to 5.5MHz if you wish. Fig. 3 shows other adjustment points and the location of the components involved in our modifications. If you do not want the inter carrier sound facility simply remove
C2236, a 5p6 capacitor feeding
R3140. In this case amplified audio
from the built-in microphone is available acorss C2230, a 47p
capacitor.
Power for the camera can be
supplied by feeding it up the coax as originally designed. However, this
requires the PSU to be well de -
III
a aamwwaimnn
The Cirkit test card on -screen result coupled for RF and overall a separate
power feed is recommended. 12V DC is normally tapped off from the modulated RF in the camera by L5171, remove this 4uH7 coil and apply +12V nominal directly to the
original connection point at the opposite side to the coax socket connection of course. An internal
regulator circuit is used to provide a stabilised 9V supply as the absolute regulation of the applied voltage is not of great importance. The current
MIC AMPLIFIER MIC
C2330
9V
L5238
C2236
INTERCARRIER SOUND FM
MODULATOR
C2136
9V TO CAMERA CIRCUITRY
9V REG
CAMERA TUBE
VIDEO GENERATION
CIRCUITRY
R3140
VHF AM MODULATOR
Fig. 2 Simplified diagram of the VK4901 CCTV camera
L5171 3 4FZEORVN
58
please mention HRT when replying to advertisements. 73 G4NXV
HAM RADIO TODAY JANUARY 1987
drawn in operation is 200mA
maximum.
Final Thoughts
This concludes the series on starting 23cm ATV and I hope that it may spur a few amateurs to have a gow on a mode which is increasing in popularity. Equipment can be
relatively cheap, aerials are far less
obvious than for other bands and as more TV repeaters are set up ATV activity is on the increase. Finally, if you're within range of GB3PV you'll be able to see how ugly my shack looks!
Suppliers
The Astec modules, received motherboard and complete kits of
L5202 MASTER OSC
VERTICAL AMPLITUDE
ct.)
R3171
BEAM CURRENT
R3214
ELECTRICAL FOCUS
R3216 R319111
9V ADJUST
fir:3_1;9 Fri:!2_21
VHF OSC BALANCE
VHF OUTPUT
® ® L5162 L5161 024103,6 L151:170
L5164 0 n 4L5171
C22300
C2236 L5238 6MHz
SOUND
BLACK WHITE TARGET LEVEL CLIPPER VOLTAGE
Fig. 3 Internal detail of the VK4901
AGC VIDEO MOD OUT BALANCE
parts are available from Comex Systems Ltd, Comet House, Unit 4,
Bath Lane, Leicester LE3 5BF (0533 25084).
Members of the BATC may obtain reciever PCB's at low cost
from the Membership Services Dept. The 23cm TV preamp kits are
available from Camtech Electronics,
8 Wortham Place, Haverhill, Suffolk, CB9 OHP (0440 62779). Kit price £22.50 +£1.00 p/p.
The DC 24 FMS transmitter is available from DC to Light, 15, Bursley Way, Bradwell, Newcastle -
Under -Lyme, Staffs. ST5 8JQ (0782 639406).
Spectrum programs and Test
Cards Eproms from the Worthing and
District Video Repeater Group, Mr. R.
Stephens G8XEU, Toftwood, Mill Lane, High Salvington, Worthing, Sussex. (0903 67228).
Surplus surveillance cameras from Astley Video Services, 34 Withington Dr, Astley, Manchester. M29 7NW (061 790 4649); also Topline Trading Techniques, Audley
House, High Street, Horningsea, Cambridge. Tel: (0233) 861153.
Test card generator kit available
from: Crikit Holdings PLC, Park Lane,
Broxbourne, Herts. Tel: (0992)
444111.
HAM RADIO TODAY JANUARY 1987
please mention HRT when replying to advertisements. 73G4NXV
59
_e_et
III/
1 2,IIII
N
9° .
o%)' 6
ezk ot<%
o-ea \)1'' 0 't(% 1/4
#
IIII
Readers' ADS
°'(04)
.(k0
e .69G7`ail Buy, sell or exchange your gear through
e#
our free service to readers.
1. These advertisements are offered as a free service to readers who are not engaged in buying or selling the same equipment or services on a commercial basis. Readers who are should contact our advertising department who will be
pleased to help.
2. Advertisements will be inserted as and when
space becomes available. 3. The insertion of advertisements will be on a
first come, first served basis, subject to condition 2. As a result, it will not be possible to guarantee the insertion of a particular advertisement into any particular magazine.
4. Readers should either write out their advertisement in BLOCK CAPITALS or type it. The first word will appear in bold. 5. The magazine cannot accept any responsibility for printers' errors in the
advertisements. However, we will do our best to ensure that legibly written advertisements are
reproduced correctly. In the event of a gross error,
at the Editor's discretion, a corrected version of
the advertisement will be printed (at the
advertiser's request) in the earliest issue in which
space is available. 6 .The magazine or its publishers will not accept
responsibility for the contents of the advertisements, and by acceptance of these
conditions, the advertiser undertakes to
indemnify the publisher against any legal action
arising out of the contents of the advertisement.
7. The magazine reserves the right to refuse to accept or to delete sections of advertisements where this is judged necessary. Illegal CB equipment is not acceptable unless specified as suitable for conversion to amateur or legal CB frequencies.
8. Advertisements are accepted in good faith;
however, the publisher cannot be held responsible for any untruths or
misrepresentations in the advertisement, nor for the activities of advertisers or respondents.
9. Advertisers must fill in their names, addresses
and (if available) telephone number in the space
provided, and sign the form to indicate
acceptance of these conditions (forms returned without a signature will not be used).
10. All that is to be reproduced in the
advertisement should be entered into the space provided on the form printed in the magazine. A photocopy is only accepted if accompanied by the corner of this page. All advertisements must give either a telephone number or address for
respondents to contact or both - these must be included in the advertisement.
11. Advertisements must be 40 words or less in length including the address or phone number
information. Telephone numbers normally count as two words, exchange or exchange code plus number.
Name Address
I accept the conditions above. Signature
Send this form to: Free Readers Ads, Ham Radio Today, I Golden Square, London, W1 R 3AB
ENTER YOUR ADVERTISEMENT HERE:
60
please mention HRT when replying to advertisements. 73 G4NXV
HAM RADIO TODAY JANUARY 1987
ReadereADS!
YAESU FRG 7700. General coverage receiver and FRT 7700 tuner, both boxed, little used. £240. Yaesu LF filter
FF5 unusued. £5. YW-3 SWR power meter unused. £10. Phone 0253 68981 (Lancs)
DATONG AD270 indoor active
antenna, complete, £25. No 1
Kent Gardens, Hetton Le Kent,
Tyne Wear, DH5 9LA. DRAE slow scan transciever mint cond. £250. Ring Worcester 775206. 2 MTR's FM mobile transceiver, standard C8800, 1 or 10
watts, fully synthesised,
mobile mount, ideal base or
mobile, scan on rig and mike,
memory. Excellent condition. £115. Phone evenings, or weekends, Chas 764 6767.
TRIO TH21E with original packing, used twice only.
Nicads, charger, BNC adaptor.
£145. G1010. Phone 044 46
42122. TRIO TS820S and complete station, mint condition. £600. Also Trio TR2400 2m hand held with accessories £195. Tel Ayr (0292) 285281. SONY stereo amplifer tuner TA1630, 100 watts per channel, £70. Trio 94S9DS receiver, good working order.
£40. KN Viceroy serves Mark
3, paintwork bad needs
overhaul, schmatic included no mic, £70. Phone Ian, Dundee 0382 623500. ADVANCE 052200 mainfraim oscilloscope, not working, £45.00 ovno, AVO transistor and diode tester, £15.00 ono. BBC model B computer with Sanyo colour monitor, dot matrix printer and cassette
recorder, includes all manuals
and some software, £475.00
ovno. Mr K. L. Phillips, 01 743
0811.
RS COMPONENTS 1986 data update pack, only £5.75, in-
cluding p&p. 01 751 0940,
Paul G1GMZ. EDDYSTONE S770R receiver
for sale 19 Mc/s-165 Mc/s 6 ranges with muting CW. AM NFM FM, later model black facia Eddystone lighthouse emblem on top, unmarked, pristine condition. Re -valved, re -condensed, re -aligned,
works, standard. £90, buyer collects. Eyles, Malvern 62385. TRIO LF30A. Low pass TVi filter, brand new in the box, unused. £20. Tel Chris 0562 754388, (Kidderminster, Worcs). COMMUNICATION receiver, realistic DX302 0.15-30MHz, USB/LSB AM digital readout, mains, battery. Morse practise output, triple conversion, wide, narrow, IF selectivity, as new. £110. C. J. Graham, 8 Oaktree Drive, Ecclefechan, Dumfries, DG11 3EH. Telephone 057-63-494.
YAESU FT290RH handheld rig
for sale, rave reviews in press,
complete with MMB21 and FBA5 with FNB4 nicad pack, costs over £300 new, will accept £200. Contact Dave on Plymouth (0752) 263276.
Handheld scanner considered
in PX with cash balance.
IC505 6m transceiver, boxed, as new, £250 ovno. T5430S HF transceiver, few minutes use, RX only, boxed, as new,
unmodified, £495. AT230
ATU, £95. Generator 1.2kVA 110/220V ac, 12V dc, hardly used, £120 ono. Telephone Dunstable (0582) 606983.
TOWER self standing 40ft lattice, £100; Teletype computer terminal, £20; FTDX401, top
band mod, external VFO, speech proc, offers! Wanted - cheap RTTY terminal eg
ZX81 plus software, hardware. Brunel University Ars, c/o Students Union, Brunel Uni-
versity, Kingston Lane, Uxbridge, Middlesex UB8 3PH.
YAESU FT707 transceiver for sale, £315, excellent condition, see it to believe it, 100w
output, 3.5-300MHz, AM, SSB, CW/W/N not a scratch. Please phone Adam, 01 874
2142, GOFJJ. ADVANCE Q1 signal gener-
ator, 7.5-250MHz, £25.
5BM254M pa valves, £1 each, gun brass pounder key with
slate base, £25. Racal RA17L handbook, £6; HRO series handbook, £4; Pye Bantam HP1FM handbook, £5; Pye Westminster W15FM hand-
book, £5. Phone 0437 2015,
evenings. AMT -2 terminal unit, as new,
AMTOR, RTTY, CW, plus soft-
ware for Apple IIE micro, £195. Tel Southport (0704)
69410. HAM INT Jumbo Multimode,
vgc, boxed, 240v ideal for 10m, £110 inc p&p or exchange for as new Sigma IV plus cash adjustment. Mr P. Hawkins, 4 Albert Road,
Cinderford, Glos.
1KW FOUR valve 240v linear amplifier, two meters, plate and load, SWR adjustment
control variable output fan etc,
£200 with two spare valves or
exchange old mechanical one
armed bandit/s. 021 747 6842, Birmingham.
KENWOOD TR2500 case spkr
mic, needs new display, £150;
2M (MM) converter, £15;
FRG7 receiver, £80; 5/8 mag
mount, £10, JVC TMP3 3" colour monitor, new, £150; Marantz CD54B, new, £150; Technics SUV4X, 60 plus 60w, £125. Call Bob Ingatestone, (0277) 35 43 78. SOMMERKAMP FT2772D like the 101ZD, good condition, DC converter, microphone, just had new valves.
Buyer tries and collects. £425 ono. Also a matching ex speaker SP901 at a reasonable price to the buyer of the FT2772D. Warwick 497497,
anytime.
TS700 2M multimode TX/RX,
FM, AM, SSB, 10w VFO and 2 Xtal chanels, RPT shift. 250v or 12v. £220. Phone 021 327 0606.
934MHz COMMTEL transceiver with mobile antenna
and extras, £330 ovno. Buyer
collects or pays postage + in-
surance. AR88D receiver, £60, buyer collects or ex-
change for Revco PA2 in -line pre -amp. Trio 120V-HF
transceiver, £270. SPC-300D
AJU, £170. Tel (0704) 892088.
YAESU FRG7700 receiver and
FRT7700 antenna tuner as new condition, original pack-
ing, manual and WRTV hand-
book. Warminster (0985)
215230, evenings. £250.
YAESU FTG7 communications
receiver in mint condition, complete with the Partridge variable frequency antenna system, £76. Griffiths, 97 Hunter Street, Briton Ferry, Neath, West Glamorgan. 0639 812377. FT79OR 70cm multimode complete with nicads,
charger, case and accessories,
vgc, £285. Bob, G 40AC
QTHR, Rochdale 50174. TRIO R-600 synthesised re-
ceiver, £210 ono. Also Yamaha
PSS401 portasound keyboard,
31/2 octaves + octave down,
10 voices, 6 rhythms, £65, or both for £260, to include 100
miles delivery. Tel: Bury St Ed-
monds (0284) 704152, even-
ings, weekends.
TRIO R-1000 communications
receiver, 200KHz-2MHz coverage, handbook, £150.
Can be seen. Edinburgh, Midcalder (0506) 880279. HAVE PHOTO relay alarm module with infra -red pulsed beam, seperate emitter and
receiver heads, control module, 250v AC, internal relay, brand new. £20 post
paid. Phonw (0207) 544342,
evenings, weekends.
ICOM IC24G 2m 10w FM transceiver, as new, boxed
with manual, plus 7/8 mobile
whip, £180. Tel 0475 673748, evenings and
weekends. HYGAIN TH3JNR three ele-
ment beam antenna, 10/15/20
metres and CD45 rotator complete with 25 metres
8 -way control cable, excellent condition. Buyer collects. £320. G4MBP. Phone Cheltenham (0242) 527651.
PYE PF5UH 70cms crystalled
R6, ni-cad, leather case, £43.00. Pye PF2 UB, three channel (less crystals), speaker/mike, ni-cad, £40.00.
Or £70 the pair ono. Both excellent condition. Technical details/information, etc includ-
ed. Please telephone: Roy GOBZT on Sedgley (09073) 78792. MICROWAVE modules, 25 watt linear amplifer, suit FT207/8, FT290 etc. 3SK88 front end. £30 ono. Phone
HAM RADIO TODAY JANUARY 1987
please mention HRT when replying to advertisements. 73G4NXV
61
Mike G4JXX, 021 773 8139.
FRG9600. All mode scanning
receiver, 60-900MHz, 5 months since new. £300.
Telephone Bishop Auckland
663324.
FOR SALE. Tono 550 com-
munication terminal, manual,
12 Novex monitor, PSU books,
RTTY Today World Press Ser-
vices, Radio Teletype Press
Broadcast, Introducing RTTY,
all 2 -year old, good condition.
£275 ono. Buyer collect, phone Chelmsford 0245
356531.
SALE: WPO DSB-2 transceiv-
er, fully built, tested c/w digital
display, £100 ono. WPO VHF
Minisynth, all crystals, built,
tested, £45. Pye W15AM
70.26MHz, £30. Pye Bantam,
FM 156MHz, untested, £20.
Ex -WD MF156 transceiver c/w
accessories, £40. G3VKM
QTHR. Tel 050277 622.
ICOM 745PS15 mint, SH6,
£820. Telephone Robby, 0698
459301, after 6 pm.
FOR SALE. 2 ele tribander
10.15.20, full size aerial, £120.
6 months old. 021 354 2877,
Birmingham, phone after 6pm.
COLOUR GENIE computer, us-
ed once, ready to go on air,
RTTY/CW, split screen, type
ahead new recorder, b/w TV.
£140. Will split or exchange
for KW2000A or KW2000B.
Pay difference, buyer collects.
III health forces sale. G3ZLN,
Ipswich 49139, Noel.
HEATHKIT SB104 solid state
transceiver.
SB604
P.S.U./Spkr. SB644 remote
V.F.O. SB634 SWR/PWR, 24hr
clock, console. £375.
Heathkit Apache TX -1,
Mohawk RX-1, SB19U side -
band adapter, one comple TX1
spares or repair. £95. DX200
receiver, mint. £75. Richard-
son, Becksyde, Cowmoor
Bridge, Stockton Lane, York
Y03 9JA. Tel 424817.
HW101 PSU, GWO, £80.
Minox B camera, £60. Mar-
coni TF144G signal generator,
sensible offers over £30. ICZE
sp/mic, nicads, vgc, £140. All
items buyer collect. G3GZH,
telephone 0582 872407.
Whipsnade.
D.N.T. B4OFM 40 channel CB
ideal for 10 metre conversion,
£25. Complete b/w darkroom,
enlarger, electronic timer,
dishes, chemicals, etc. £35.
G3GZH, telephone 0582
872407. Whipsnade.
U.S.A. ImA meter 2 3/4 " round -
body, £3; others flexible drives
71/2", 101/2", M,F 1/4" ends, £2
each. YAESU FSP1 8ohm
speaker, mobile, extension,
£4.50. Wanted - Service
manuals F.D.K. expander 430
(late) and 750E. Can post. G3MBL (Bury St Edmonds) 0284 60984.
YAESU FT726R. 2m + 70cm narrow CW, filter fitted with 90 watt tono linear, pristine
condition, boxed with
manuals. £650 ono. Tel even-
ings (0203) 456128,
Coventry.
FOR SALE. Oscilloscope, Hitachi dual beam model
V -152F 15MHz, probes, carry
case, vgc. £175. Phone 031 668 3451, after 6 pm. SUPERSTAR 2000. Mint con-
dition, offers over £130, also Cobra 148 GTL PX 20+ -KC shift no gaps!, G.W.O, £95 ono. Tristar 777, G.W.O SKCSHIFT. Offers around
£90. W.H.Y. Tel 0934 511604.
IC7LOA TCVR amateur bands
plus general coverage RCVR, vgc, used regularly. £550. Tel
East Grinstead (0342)
312374, GOCJU.
FT29OR YAESU 2m portable
transceiver, complete with carry case, ni-cads, charger and rubber ant. Boxed, one year old, used very little, £255. Phone Leic (0533)
875192 (Evenings).
FOR SALE. AR2002 receiver,
as new £350. London. Tel 228 4835.
OSKERBLOCK SWR/Power meter ohm, 75/52 ohm, £22.
2 meter converter, £12. Semi-
automatic bug Key KY102, £8.
Pair 7.1 Wight traps, £7. 8 years Rad/Com 1978-1986,
£6 per year. All post paid, Trio TL911, 2KW HF linear amp,
revalved. £300 + carr. GM3CAN QTHR. Phone Bonnybridge 8124269.
3 WATT amplifier's. £2.00. Tel
383380. 16 Low Hatters Close, Downham Market,
Norfolk.
AR2002 scanner, almost new,
boxed, £360 or would ex-
change Realistic DX400 plus
£200. Cash adjustment, buyer
collects. Phone Blackpool (0253) 27406.
BRITISH NATIONAL Radio and
Electronics course for sale or WHY. Cost £50; never used,
ring Stan, Carvell 021 744
9371, daytime 021 459 4913.
FOR SALE. CWR610 RX unit CW/RTTY. Prince Green
monitor, £175 complete. Tel Don 0227 721400.
FRG9600 25-905MHz mint
condition, £375 ono. P.
Spencer, 39 Fen Road, Heighingon, Nr Lincoln,
LN41JL, Tel 0522 792640.
WANTED
WANTED. Yaesu 7700
receiver or similar, reasonable
price please. Mr Harris, 6 Pan-
dy View, Trelewis, Treharris,
Mid Glam, S. Wales. Tel.
Treharris 411664.
A FREE GIFT. Can anybody
supply me with a copy of the
Complete
Frequency
Coverage for the Whole Audi-
ble Radio Range and it's
Allocation. Please, I will copy
and return or you copy for me,
I will pay all expenses, and will
give yo a free gift for your help.
Please call Brian, Brighton
(0273) 559373.
WANTED. 902DM with hand-
book, etc. Fair condition, fair
price. G3ICG. QTHR. Phone
Ipswich 0473 688491,
anytime.
WANTED. COBRA 148,
superstar 360, Hy -Gain V.
Must be in perfect condition.
Tel Belfast 795783.
WANTED. EDDYSTONE EC10
MKII manual to buy, borrow or
copy. Geof Tonge, 19 Long-
meadow Road, Saltash PL12
6DW. 075 55 3533.
WANTED. Ham Radio Today, February 1983 edition. Ex-
change C -scope 3000 ADC
metal detector, cost £250 for
HF, VHF, UHF, WHY? Phone
Colin, Sedgley 64486.
WANTED. Urgently by han-
dicaped operator. Kenwood
T -599S TX, either cash or ex-
change for my converted
Cobra 148 GTL-DX 28.0MHz
to 29.7MHz, m/mode, inc CW
or any of three 2 mtre FM,
Mobile rigs, Peter G1TX1, 2
Mayes Close, Norwich, NR5
9AR.
UEL COB. Handheld AM/VHF
transceiver, does anyone have
circuit details or technical in-
formation that I can borrow to
copy? or will pay for copy and
postage etc. Phone George,
Runcorn 09285 75904.
WORDPLEX word processor,
technical information and/or
circuit details required. Borrow
to copy or pay for copy and
postage, etc. Phone George on
Runcorn 09285 75904.
WANTED. Operators manual
for Yaesu FR DX 400 or photo-
copy. Tel Burley 2447. QTH 33
Warmes Lane, Burley, Hants
BH24 4EH.
WANTED. Good Multi band receiver, capable of receiving marine, air, emergency services etc. Age not important, also person willing to teach raw beginner amateur radio.
Willing to pay modest amount,
please contact A. M. Guy 16
Goulbourne Road, St Georges
Shropshire TF2 9LE.
STINGY FATHER desperately
needs cheap 2m hand-held or
2m mobile multimode for
son's 18th birthday. Phone Jeremy, Berkhamsted (04427)
71386.
WANTED. Service manual for
W15U Pye Westminster, original or photocopy, also April 1986 edition of Ham
Radio Today. Please write to Mr A. Holmes, 61 Surtees St,
Bishop Auckland, Co. Durham.
DL14 7DJ. WANTED. Quality receiver, by
enthusiast returning to hobby,
RA71 or similar etc. Cash
waiting, will collect, N.W. area.
Please phone Rob (051) 263 3026. WANTED. Yaesu FT78OR 70cms mobile. Phone evenings, Chas, 01 764 6767. WANTED. Integrated circuit type MC1349P, G3ADS, 21 Newcome Road, Farnham, Surrey GU9 9DJ. Phone 0252 710501. WANTED. Heathkit AFM:TI tuner (working); 533H amplifier (spares, cheap); General coverage receiver,
working, (Eddystone, Marconi,
Hallicrafters, etc) must be cheap. Avometer model 8 or
similar, cheap. Have Pye L75B battery (90v +11/2 v) receiver.
Sale or exchange. Birmingham (021) 770 9510.
WANTED. Top quality loop antenna for medium wave. Good price for best available. Ring (0772) 704009, after
6pm.
WANTED. RACAL MA144
ATU, condition not important, but must be original and no
mod's. Top price paid, will col-
lect, distance no object. £1 or G. Land. Also RA63G SSB adaptor. Write or phone. G.
Fitz -Gerald, E16DP. 40 Maigue
Way, John Carew Park, Limerick, Ireland. Tel
061-43584.
WANTED. KW109 Super
match ATU, must be ex cond.
Tel Pete, Nuneaton 343680.
WANTED. Free standing exter-
nal digital display for FRG7 plus instructions. One was by
MG Communications, approx
62
please mention HRT when replying to advertisements. 73 G4NXV
HAM RADIO TODAY JANUARY 1987
year 1980. 31 Edward Ave,
Jacksdale, Notts. NG16 5LB. WANTED. Discone antinna, 25MHz 500MHz, good condition. Phone 0476 66047.
WANTED. General Coverage
Communications receiver JRC NRD525 or JRC NRD515 or
Panasonic RF900 or Sony CRF
330/320 or Sony ICF 2001D. Either one in good condition. Tel Bristol (0272) 570330 or 663222.
WANTED. Trio all band SSB
transmitter, model MOTX 310.
Ring John 0772 715045. WANTED. FTV901 complete with all module if possible.
Phone after 6pm (0268) 24453 or day (0268) 3040
extn 637 Ron.
WANTED. Buy or borrow handbook on Heathkit DX -100v. G4VGS QTHR
02774 4177. D. A. Whitbread,
284 Perry St, Billericay. WANTED. Pye Westminster model W15U. Serviceability immaterial but must be com-
plete. Phone 0689 29116
(Kent).
WANTED. Sommerkamp 788DX or 30-40 HD PSU or any F707 accessories or
SPC3000/TU SPC300UTU in exchange for 48K Spectrum, micro drive, interface I, book and leads, boxes and casset-
tes, b&w monitor 12". Also have Plustron TVRDL TV, radio and music centre com-
bination, portable, will exchange. All or most if offers
good equipment and genuine deals. As well as reasonable financial offer I would like to swap a KW107 for a SPC300 or the KW107 plus KW227
ATu for a good working
SPC300. G4XPP, QTR.
WANTED. Any information on NDI HC1400 2m FM TXRX owners manual, service info required. Also mobile moun-
ting bracket for above rig.
Please contact Jerry, GOCUO
QTHR 091-4107884 (Co
Durham).
QUALITY digital general
coverage receiver required. Will consider up to half original
cost. Offers to Mr Welsh, Maldon (0621) 54547
(Essex).
RADIO/RADAR EQUIPMENT
WANTED by private collector:
Receivers CR100, BC348, HRO Senior, Collins 75A4, APR4 and tunint units, and any radar surplus units including transmitters, receivers, modulators, indicator
units, etc. Will collect. R Bristow, 6 Finmere, North Lake, Bracknell, Berks.
WANTED. Ham Radio Today,
December 1984 or photocopies of part 4 Alpha Transceiver and Project Omega, money will be refunded.
WANTED. Front panel (Plastic
and fascia) Cobra 148GTL DXII. D. Jones, 6 Ashfield Road, Shotton, Deeside, Clwyd CH5 1AQ. WANTED. Pye model M78F
personal battery receiver. This
set has the Pye rising sun emblem with a black and
cream plastic case. Fair price paid. Please contact Stan, G3XON, 14 Dagden Road, Shalford, Guildford, Surrey
GU4 8DD. Tel Guildford (0483) 36953. WANTED. FP707, FP700, FP757 HD or similar 20amp commercial power pack.
G3KNA, phone 0274 873122.
WANTED. Doctor DX cartridge
for C-64. Must be in GWO with instructions. Phone after
6pm, Andrew, G1SKT, 0902 753567 (Wolverhampton). WANTED. Yaesu FRG7 or
FRG 7700 receiver, reasonable
price for blind son. Phone (0272) 657666. (Bristol) WANTED. IC211E, preferably
with Mutek front end, must be in very good condition, with
manual. For sale FM03 FM IF strip for IC720/A. New with CCT and all instructions. £40
(Cost £80 from Thanet)
G4CTE QTHR. Phone Grimsby
(0472) 840367. HRO. Can you, with love and
devotion, mend mine? Phone
Julian 01 876 8113, Kew, Sur-
rey, evenings.
WANTED. HF linear amplifier,
commercial or home brew. Any condition considered. Tel 0608 811102.
WANTED. Lowe Mk1024 elec-
tronic keyer with memory, also
Sony TV-511UK and Sony KV-9000UB. Must be in first class condition. Phone 0206-394336. Essex.
WANTED. Good quality used equipment, HF, VHF, UHF WHY? Cash waiting for the right article. I have lots to sell,
swap and part ex. Phone
0924 495916 or write Martyn
Bolt, 112 Leeds Road, Mirfield,
West Yorks, WF14 OJE
(G4SUI).
HF TRANSCEIVER wanted
with or without general
coverage receiver. Also any associated equipment, late
model/s, 2m rig also. Please call after 6pm. G3GZT. 0273 503869, giving details and prices.
WANTED. FT225RD, cash
paid for rig in any cond, prefer
with Mutek and memory unit.
Also 144MHz QRO valve
linear home brew considered. Also Mirage MP2 meter. Will collect any distance. G4JBH
QTHR. 0935 23873,
evenings.
WANTED urgently, KW EZEe
match antenna tuner, your price paid, all letters answered. Art Smyth, 8 Cleave Crescent, Morwenstow, Bude, Cornwall EX23
9J H.
txCHA
EXCHANGE Sanyo video
5000, mint, Beta, low mileage,
incl 5 tapes for FR5OB or
9R590S or FR100 or JR500 or CB multimode or sell for £78. Ring 0634 63752 or 660037. EXCHANGE Mint Trio 9130,
10 hours TX only, plus 100 watt mm linear for good HF
transciever + ATU or sell £550. Colin PO Box 79,
Gloucester.
EXCHANGE BBC B computer, boxed, unused, 2 x Sony ICF
7600D receivers, 48K spectrum Plus, lots of software, hardware, waffer drive, Datong active atenna, RC oscillator, Harrier base station CB. WANTED 2M base rig,
FT209 R/H, NC15 base
charger, 2M + 70cm linears, UHF wave meter, 23cm ATV gear or WHY. G6RBK 0923 662817, after 9pm. EXCHANGE Yaesu FT7 HF
transceiver plus FP12A PSU in
nice condition for Trio TS700G, 2 meter, multimode
transceiver or similar rig. Don't be shy, give us a ring. Allness 882941 or write G. Matthew, 2 Old Milnafua Road, Alness,
Ross -Shire IV17 OTW. EXCHANGE Prinz Compere
Super 8 projector and Chinon Classic 722 auto 200m lens
cine camera all as new for
medium duty rotator or HF TX, ATu 100W +. Mr J. Graham, Clintpark, Ecclefechan, Dumfries. Phone 057 63 615.
EXCHANGE Eddystone 640C
receiver 1-30MHz BFO etc and Pye pocket fons 2PF WFMB with batts, mics, etc, will convert to 2M or Marine, G.W.O. Swap for compact VHF/UHF receiver or Murphy CB home
bse and H/base mic. Phone
Mike, after 6pm, 0243 56523.
VOIGTLANDER VSL 3-E
1.8/50 power winder, Tamron
mount, 2x converter, Tamron
28-70 wide angle, new.
Tamron 80-210 macro zoom,
Vivitar 2500 bounce zoom thyristor flash, Hitacon auto 3000C cut off bounce flash,
mint; EXCHANGE for modern
digital communiation receiver ie. Yaeso 4-600.
EXCHANGE Ham International
Jumbo compatable for 10mtrs
swap for Yaesu FRG 700.
Phone evenings, 01 783 0521, ask for Adam.
PENTAX ME Super 35mm SLR camera, with 135mm, 28mm lenses, flashgun, and tripod. All as new. Will exchange for 70cms multimode
transceiver. Phone Stuart
(Gippy) after 5pm weekdays,
anytime weekends 0604
847009. EXCHANGE Spectrum 48K new condition, with RTTY/CW
program for HF amateur band,
RX in good condition, FL200B,
FL400B, WHY. Chris, Falkirk (0324) 26210.
EXCHANGE TS430S PS430 for HF TXCR preferably Icom to operate Amtor RTTY. S. Hudson (0480) 53775. 70cms TRANSCEIVER wanted, exchange for 3Y2"
reflector telescope. F460 Pye base station, UHF, tuned 456MHz. Requires retuning to 432MHz. £40 ono. G8BSK, 290 Priory Road, St Denys, Southampton SO2 1LS.
EXCHANGE. Wanted Commodore 64 or 128, also disk
drive. Exchange for Ham International Concorde II and HI
TW232 DX microphone,
and/or fully automatic electronic GGG incubator. All as new and boxed with instructions. (Never been tampered with!). Phone John 084 82
314.
EXCHANGE ATV station,
microwave modules MTV435
transmitter and ATV converter. RCA2000 camera 16mm lense. KGM 12 inch monitor with maintenance handbooks, for 70cms
multimode transceiver. Phone Johnstone 24930.
EXCHANGE. Inflatable yacht
tender complete with floor boards, anchor LJ's etc, with
2hp Suzuki ob engine, all as
new. Worth £250 for good HF rig, cash adjustment if re-
quired. Tel (0562) 67026 (Kid-
derminster) anytime.
HAM RADIO TODAY JANUARY 1987
please mention HRT when replying to advertisements. 73G4NXV
63
Lineage: 48p per word VAT inclusive (minimum 15 words) Semi Display: (minimum 2 cms) £7.35 per single column centimetre. Ring for information on series bookings/ discounts. All advertisements in this section must be prepaid. Advertisements are accepted subject to the terms and conditions printed on the advertisement rate card (available on request).
lv
01-437 0699 Ext 289. Send your requirements to: Ham Radio Today Class. Dept., ASP Ltd., 1 Golden Square, London W1R 3AB
COURSES
COILS AND
CARDS,
RADIO AMATEUR LICENCE
Start training now - No previous knowledge required. Study for 3-6 months. Post Coupon now for free brochure - without obligation:
Radio & Telecommunications Correspondence School, 12 Moor View Drive, Teignmouth, Devon.
Tel: 06267 - 79398.
(HRT/J)
-CHOKES
MAXI
COILS AND CHOKES PREVIOUSLY MADE
BY DENCO SAE PRICE LIST
8 BRUNEL UNITS, BRUNEL ROAD,
GORSE LANE IND ESTATE, CLACTON,
STICKERS
G4TJB qsl cards Personal ana standard designs. SAE Samples. 100 Matt colour DIY £2.50, Gloss £3.50. LOGBOOKS £2.20 (mobile £1.20). BURO ENVELOPES £1.00 (20). NAVY SPECIAL MOBILE AND BASE HF ANTENNAS. SAE for
details: G.C. PATTERSON G4TJB. 24 Portishead Road, Worle, Weston Super Mare, Avon BS22 OUX.
OSL CARDS. - try me for quality and price. S.A.E. for samples. A.W. Bailey (G3YNI) Breandown Press, Wick Lane, Lympsham, Somerset.
NAME
ESSEX C015 4LU. TEL: (0255) 424152
ICOM PORTABLES
ADDRESS:
POST CODE
FOR SALE
AERIALS
ANTI-T.V.I. Aerials, traps beams or wire aerials, baluns, kits etc. Data 26p large SAE. Aerial guide El . G2DYM Uplowman. Tiverton, Devon EX16 7PH (03986)
215.
NEW SHOP LUTON: Come to us for your aerial requirements! We also repair, install and calibrate
COMPUTER EQUIPMENT
68008 SINGLE BOARD COMPUTER, contains:- Disc Interface, Colour Display, 8K Monitor, Megabyte RAM, 2 Serial/
Parallel Ports, RTC, runs SK -DOS 68K. Bare P.C.B. or built. Also 6809 Micro -Set System. S.A.E. Ralph Allen Eng, Forncett-End, Norwich.
G3LLL'S 6M BARGAINS
FT69OR £329 p.p., 6M units for FTV 901
£139 p.p. J -Beam 4 El. (Callers only) £43.
Valves type approved Yaesu
Mkt -8
6JS6C NEC £30.75 p.p. FT 401 6KD6
(Green banded) NEC £33 p.p. 6146B G.E.
FT 901/101ZD £27.25 p.p. NEC 12BY7A
£10 p.p. Improve your FT 101 MK1/E.
Double balanced mixer £17 p.p. 3 band
WARC kit £16 p p State Model.
HOLDINGS/AMATEUR ELECTRONICS,
45 Johnston Street, Blackburn BB2 1EF
Tel: (0254) 59595.
ICOM PORTABLES
MRZ DESK TOP PSU FOR ICOM PORTABLES:
2E/4E/02E/04E
Incorporating overvolts protection; overcurrent shutdown: £61.95 x £3.00 carnage.
(Reviewed page 8 July 'HRT') Models available for PMR/Marine !corn's.
MRZ 6 amp (continuous) 12v. DC PSU: £59.95.
MRZ FOR ICOM 8 YAESU EQUIPMENT, MRZ COMMUNICATIONS LTD. 248, Uttoxeter Road, Longton, Stoke on Trent. ST3 SQL Tel: 0782-619658 (24 hours)
MISCELLANEOUS
amateur equipment. Wide range of CB & p.m.r. also available. Ring 0582-458310.
CB AND ACCESSORIES
SERVICE MANUALS
Our next copy deadlines are
as follows: March Issue
HEATHKIT U.K. spares and service centre. CEDAR ELECTRONICS, Unit 12, Station Drive, Bredon, Tewkesbury, Gios. Tel: 0684 73127.
INSTRUMENT REPAIRS,
THE NORTH's Leading C.B. Distributors including 934 Mhz equipment. Please ring 0388-528464. Ian Fisher Communications, CB Works, Stanhope, Co. Durham
rDL13 2YT.
SERVICE MANUALS. Amateur radio, test, audio, TV, video etc.
Thousands stocked. SAE
enquiries. Mauritron (HRT), 8 Cherrytree Road, Chinnor,
Oxon.
23rd December April Issue
28th January
Oscilloscopies, generators, multimeters and more. Viking Electronics, Potkins Lane, Orford, Suffolk IP122SS Tel:
0394 450006
1
CLASSIFIED COUPON
Lineage 48p per work (inc VAT). Minimum 15 words. Semi display £7.35 per single column centimetre. (Minimum 2cms). No reimbursements for cancel-
lations. All ads must be pre -paid.
(HAM RADIO TODAY) Classified Ad Dept. ASP Ltd,
No.1 GOLDEN SQ. LONDON W1R 3AB.
Name
PLEASE DEBIT MY ACCESS/BARCLAYCARD No. Address
II
Tel. No. (Day)
EXPIRY DATE
FOR £
FOR
INSERTIONS
El FOR SALEID COURSES
VISA
Signature
COILS &
1-1
CHOKES U AERIALS ACCESSORIES U Please state
Date
NMI
64
HAM RADIO TODAY JANUAHT 1987
BIRMINGHAM
AMATEUR idarrh ELECTRONICS I IL, LTD
510-512 Alum Rock Road, Alum Rock, Birmingham B8 3HX. Tel: 021-327 1497/6313 Ciai7
YAESU DISTRIBUTORS TO THE UK.
BIRMINGHAM
CENTRE ELECTRONICS
345 Stockfield Road, Yardley, Birmingham B25 8JP Specialist in the sale and service of Ex Govenment
and Vintage Radio and Test Equipment. (Many spares in stock).
Telephone enquiries to 0676 32560
Special delivery service
Shop open Thursdays, Fridays and Saturdays
ESSEX
SELECTRONIC
The UK's leading suppliers of 934MHz personal radio equipment
203 High Street, Canvey Island, Essex Tel: 0268 691481
(Open Mon -Sat 9-5.30) Amateur radio equipment also in stock
KENT
ELECTRONICS 2 Stanley Road, Herne Bay, Kent
Tel: (0227) 369464
Open Mon -Sat 9-5.30pm
O except Thursday 9-1pm 0
I
BIRMINGHAM
R. WITHERS
c
COMMUNICATIONS
584 Hagley Road West
Oldbury, Warley B68 OBS (Quinton B'Ham) Tel: 021-421 8201/2/3
Opening hours 9-5.30pm Late nights Thurs-Fri. Send just .£1.00 (refundable against purchase) for latest catalogue our exclusive products & used list.
BIRMINGHAM
HEWARD'S HOME STORES LTD.
(Est. 1963) 822/4 Kingstanding Rd., Birmingham B44 9RT.
Tel: 021-354 2083 G4RJM with 38 years in The Radio Trade
Ham Equipment urgently wanted! Open: Mon -Sat 9-6
CHESHIRE
LANCASHIRE
AMATEUR ELECTRONICS/HOLDINGS G3LLL.
YAESU. JAYBEAM. DRAE. DATONG. BLACK STAR COUNTERS.
- - ETC. FT 101 EXPERTS.
6JS6C 6KD6 12BY7A Original type approved valves F. our own Double Balanced Mixer and new band WARC Kits for original FT 101 MK1 -E S.A. E List. Full Yaesu range 15 mins Junction 31 M6 Free parking Call and consult G3LLL without obligation 45 JOHNSTON STREET. BLACKBURN 912 1EF. 10254159595. CLOSED THURSDAY.
LEICESTERSHIRE
ELLIOTT ELECTRONICS
for the Radio Enthusiast
26-28 BRAUNSTONE GATE, LEICESTER. TEL: 553293
Open: Mon -Sat 9.00am to 5.30pm
LONDON
DW ELECTRONICS G3 XCF
Amateur Radio Supplies 71 Victoria Rd, Widnes enlICOMI
Tel: 051-420 2559
Open Mon -Sat 9.30-6 (closed Thurs)
We supply Yaesu, Icom, Tonna, Jaybeam, Microwave Modules, Datongs, etc.
UK LTD
AR?DR1E91SFrSanLcisERRd., Layton, E10
Open 9-5.30 Monday -Friday 10-5 Saturday
Authorised dealers for: Dressler, Yaesu, Icom, Standard, Kenwood, Datong, SCM, Microwave Modules, Tonna Tel: 01-558 0854/556-1415 Telex: 8953609
DEVON
AGRIMOTORS
Merton CB & Radio Centre
Merton Garage & Post Office, Merton. Nr. Oakhampton EX20 3DZ. Open 6 days 9-6 (Sundays by appointment) Specialists in 934MHz
Suppliers of al127MHz and 934MHzequipment
HAM RADIO TODAY JANUARY 1987
MERSEYSIDE
ARE Communications Ltd
FOR - YAESU, ICOM & KEN WOOD Phone us for the best deals on all amateur radio equipment.
38 Bridge St., Earlestown, Newton -Le -Willows, Merseyside. Phone: Peter G4KKN on 09252-29881 Opening hours Tuesday -Saturday.
10am-5pm
NORFOLK
D.P. HOBBS (Norwich) Ltd
13 St. Benedicts Street, Norwich Tel: 815788
c.-4-7
Open Mon -Sat 9-5.30
Thurs 9-1pm.
IICOMI
Stockists of:
YAESU, FDK, ICOM, JAYBEAM & Electronic Component Specialists
NOTTINGHAMSHIRE
SP ELECTRONICS
48 Limby Road Huckhall, Nottingham
Tel: (0602) 640377 Open Monday -Saturday 8.30-5.30
N. IRELAND
where it will be seen. Ring 01-437 0699 for Advertising details.
SCOTLAND
JAYCEE ELECTRONICS
JOHN GM3OPW 20 WOODSIDE WAY, GLENROTHES
FIFE KY7 5DF Tel: 0592 756962
Open: Tues-Sat 9-5 Full Range of YAESU & TRIO Goodies. Quality Secondhand Equipment in Stock. JAYBEAM - MICROWAVE MODULES - LAR
SURREY
GUILDFORD COMMUNICATIONS 34 Aldershot Rd., Guildford
Open Mon -Fri Sat 8am-5.30pm
com
ASDEN
C=I Secondhand wanted VISA 0483-574434
N. WALES
NORTH WALES AMATEUR RADIO MART
AMATEUR RADIO - CB RADIO - MARINE RADIO - P.M.R.
25 ABBEY STREET RHYL
Open Monday -Saturday: 11am-5.30pm All repairs and accessories available ex
stock. Mail order welcome. Tel: 0745-51579
65
Etif0111111161110E
W. MIDLANDS
.
DEWSBURY ELECTRONICS
RXs, from YAESU. JRC, ICOM.
'tockists of microwave modules. EN.O.S., M.E.T.
GAMMA DATONG, ICS, TASCO.
Open Mon -Sat, 9-30-5.15
176 Lower High Street EniStourbridge (0384) 390063
WORCESTERSHIRE
A. KELLY
Electronics & Communication equipment. 3 Stoke Road, Aston Fields, Bromsgrove,
Worcs 860 3EQ. RSGB Publications, Mutek, DRAE, Microwave Modules, Star Masterkeys, TAL aerials, Alinco.
OPEN 6 DAYS A WEEK EVENINGS BY APPT. 0527-71165.
YORKSHIRE
Amateur Electronics UK Alan Hooker
42 Netherhall Road, Doncaster
Tel - 0302 25690 Large stocks of electronic
components.
GUIDE COG /1011
Price per insertion (+ VAT): £16.80 for 1-5, £16.00 for 6-11, £15.25 for 12 or more. Please enter details of your retail business below:
COMPANY NAME ADDRESS
TELEPHONE NO: OPENING HOURS:
OTHER INFORMATION (briefly)
ADVERTISERS INDEX
AKD Allweld Engineering Amateur Electronics BNOS Cirkit Dewsbury Electronics Dressler UK Elliot Electronics Farnborough Communications Garex Electronics JEP Electronics A Kelly
KW Ten-Tec
26
67 Lowe Electronics
43 MH Electronics 14 Microwave Modules
23
34, 35
27 6, 7
33 Quartz lab
33
68 R.A.S. Nottingham
27
9 Spectrum Communications
33
43 Technical Software
27
27 Thanet Electronics
4, 5
67 Waters & Stanton
8
West London Communications 33
27 Ray Withers Communications
2
42 Wood & Douglas
8
66
HAM RADIO TODAY JANUARY 1987
roce-.."-...zo"...."-orsoccezr...0.0 A R
JIL SX-400
THE PROFESSIONAL SCANNER * Basic coverage 26-520Mhz AM, NFM & WFM Expandable from 100kHz to 1.4GHz with SSB and CW Computer control options IF output terminals * Specifications set by professionals
£649_,
ExTHE SCANNER_,..,
SPECIALISTS
REGENCY MX -8000
THE WIDER RANGE SCANNER
The receiver with the most Megahertz for your money * Covers: 25-550MHz, 800MHz-1.3GHz * AM & NFM & WFM on all bands * Computer interface socket 20 memories * Compact size 12v dc operation Up/down step control knob
(111111
£487 Q
REVCO RS -2000E
REGENCY HX-2000E
Q0
THE VERSATILE SCANNER
THE HAND-HELD SCANNER
Covers: 60-180MHz, 380-520MHz
Covers: 60-90MHz,
till
AM & NFM on all bands Search & store of active
118-175MHz, 406-496MHz AM & NFM on all bands
Milli
channels Channel activity counter
Full scan & search functions 20 memories
(till
70 memories
Nicads, charger & whip antenna
`chill
" 12v dc & 240v ac
£279
included
£279
0 0
JIL SX-200N
THE SUPERIOR SCANNER
DON'T FORGET THE ANTENNA!
0
Q
All receivers need a good antenna and the deal one fora scanner Is the
REVCONE. a 16 element discone Made in Bntarn by Revco a company that has
The choice of the professionals Proven reliability
been manufacturing quality antennas for the last 25 years the REVCONE covers
50-500MHz. is extremely well made and very good value al psi
£29.95
Also available - the RAOAC dipole nest 25-500MHy with extra
till
Covers: 26-88MHz, 108-180MHz, 380-514MHz
performance
PRE -AMPLIFIERS
E69.95
0
AM & NFM on all bands
Broadband antennas usually have no gain. so pre -amps are often desirable. One
Positive action keyboard 16 memories 12v dc & 240v ac
mounted at the masthead amplifies the weak signals but not the noise generated
in the feeder cable The REVCO PA2 in-rine masthead pre-amolifier gives usel ul gain froml0MHz to over 1 OHS
Includes special mains psu
C49.95
The MUTEK BBBA500u is Intended for use at the receiver s input Requires 12v
0 0 0
£325
DC at a few mA.
C35.50
s
VISA
GAREX ELECTRONICS
7 NORVIC ROAD, MARSWORTH, TRING, HERTS. HP23 4LS. Phone 0296 668684. Callers by appotntment only.
MAIN DISTRIBUTOR OF REVCO PRODUCTS. PRICES INCLUDE UK P&P and 15% VAT. Ask for details of our interest free credit.
0)
Extensive range of PYE radiotelephone spares-S.A.E. for list.
Ask for our list of second-hand scanner bargains.
MN MIL IN
11
111IIIIMR NI
OM MEL IM
NNE 11
NM MI In IM
PROFESSIONALS AND DISCERNING RADIO AMATEURS ALWAYS CHOOSE
THE TOWER PEOPLE
COMPACT LATTICE TOWERS-SLIMLINE TUBULAR MASTS
Telescopic-Tiltover, Fixed-Mobile from 3M to 60M. Over 50 Models, suitable for a wide range of civil and military applications such as:
Radio Communications Amateur Radio CCTV and Surveillance Meteorological Monitoring Aero & Marine Nav Aids Flood Lighting etc.
Purpose designed using 4.5m and 3m section modules for low retracted heights and cost effective shipping. Engineered to B.S.I. standards and hot dip galvanised to BS729 for protection. Wind loads are based on BS CP3 CHAP V PT 2 1972 for wind speeds up to 100mph/160kph.
RELIABILITY-QUALITY-KNOW HOW.
o
SEND S.A.E. FOR FULL DETAILS.
11
WE DESIGN-WE MAKE-WE SELL-DIRECT. No Middle Man.
17
At manufacturers prices-you get best value.
12 11 03
1Z;
-= MUM
BARCLAYCARD
IIIML EN MN MM
/I
ALSO SPACE SAVER 3ele 4 BAND AQ6-20 BEAM 169-00 + 7-00 CARR.
\ Stock items normaly sent within 7 days:
HP TERMS AVAILABLE
ALLWELD ENGINEERING
Factory 6, 232 Selsdon Road, South Croydon, Surrey, CR2 6PL Tel: 01.680 2995 (24 hr) 01.681 6734
MIU II
MI
imam Rom mmi
I
mom a_
7
DEIVEIB'URY
ELECTRONICS
AT LAST!!! AN FM BOARD FOR THE TS -930 S AND MANY OTHERS
NOW FROM THE MAKERS OF THE WORLD FAMOUS STAR MASTERKEYERS, AN 'FM BOARD' FOR THE TRIO TX -930s.
THIS EASY TO FIT READY BUILT BOARD, ENHANCES ALREADY SUPERB FACILITIES AVAILABLE ON THE TRIO TS -930s.
EASILY FITTED TO THE TS -930s. THE FM BOARD IN NO WAY DEGRADES THE PERFORMANCE OF THE TRANSCEIVER, ALL MODES INCLUDING FM ARE READILY
AVAILABLE. SUPPLIED AS A READY BUILT UNIT, COMPLETE WITH CONCISE AND EASY TO FOLLOW
FITTING INSTRUCTIONS, CAN BE INSTALLED IN LESS THAN 90 MINUTES, OR FOR A MODERATE CHARGE, DEWSBURY ELECTRONICS WILL BE HAPPY TO FIT THE UNIT. COLLECTION AND DELIVERY ARRANGED. FOR FULL DETAILS AND SPECIFICATION,
PLEASE SEND S.A.E.
STAR MASTERKEY CMOS MEMORY KEYER
8 MEMORIES, BEACON MODE, DIRECT & GRID BLOCK KEYING. FULL DETAILS IN PREVIOUS ADS. STILL ONLY £95.00.
STAR MASTERKEY MKII
DOT - DASH MEMORIES IAMBIC OR SIDE SWIPE, SEMI AUTOMATIC
MODE, 12 VOLT OR INTERNAL BATTERY PRICE £54.70.
FULL RANGE OF BENCHER KEYS
POST, PACKING AND INSURANCE ON EITHER KEYERS £3.00.
FULL RANGE OF TRIO PRODUCTS STOCKED We are also stocked of DAIWA - MET ANTENNAS - POCOM - JRC - TAR - TASCO TELEREADERS
MICROWAVE MODULES - ICS AMITOR AEA PRODUCTS DRAE
Dewsbury Electronics, 176 Lower High Street, Stourbridge, West Midlands. Telephone: Stourbridge (0384) 390063/371228. TELEX: 337675 TELPES G
Instant finance available subject to status. Written details on request.
PdfCompressor 6.6.1697 CVISION Technologies