Lafayette HE-45 6 Meter Amateur Band Transceiver

Specifications

Receiver

Superheterodyne receiver covering the entire 6 meter (50 to 54 Mc) amateur radio service. Built-in noise limiter control with improved full wave automatic and adjustable noise limiter and full AVC. Illuminated channel tuning dial with planetary vernier tuning. An "S" meter calibrated in S units allows measurements of incoming signal strength. The meter is wired with a switch to enable monitoring of final transmitter amplifier wattage.

• SENSITIVITY: 1 microvolt.
• SELECTIVITY: 3 KC at 6db down.
• IMAGE REJECTION: 45 db.
• I.F. FREQUENCY: 1650 KC.
• NOISE GATE LIMITER: Adjustable type.
• AUDIO OUTPUT: 3 Watt, 4" Alnico V Speaker.

Transmitter

• POWER: Power input of 12 watts to the final Straight-through class C 2E26 RF amplifier.
• FREQUENCY: 6 switch selected transmit positions. Supplied with crystal for one frequency. Widely tuned for full efficiency on the entire 6 meter band.
• MICROPHONE: Hand held ceramic microphone with 2 position slide switch; Position one - microphone in receive position; Position two - microphone in push to talk position. Spring release switch.
• ANTENNA MATCHING: 30 to 100 ohms.

Controls

• RF PEAKING CONTROL
• VOLUME ON-OFF
• PLANETARY TUNING
• NOISE LIMITER CONTROL (Adjustable type)
• CRYSTAL SELECTOR: 5 crystal controlled fixed transmitting frequencies plus a sixth position for an external V.F.O.
• RF METER INDICATOR: 2 position switch controlled. Position one - reads Transmitter plate output current. Position two - "S" meter with built-in zero adjustment control.
• SPOT SWITCH: Crystal calibrator to check calibration of receiver's frequency dial.

Power Requirements

• Operates on 117 VAC and 12 volts DC, with proper supplied cables. Battery operated cable internally fused.
• 117 Volts AC 60 cycles: 60 Watts Receive, 85 Watts Transmit
• 12.6 Volts D.C.: 6 Amps Transmit, 4.5 Amps Receive

Physical Specifications

• SIZE: 5 1/2" H x 12 1/2" W x 8" D.

Product Overview

The Lafayette Model HE-45 transceiver is a combination transmitter and receiver designed for use in the 6 meter (50.1 to 54 Mc) amateur radio service. Designed to meet Federal Communications Commission (FCC) requirements, the unit provides economical and reliable radio communication when installed and operated according to these instructions.

The transmitter operates on any frequency in the 6 meter amateur phone band (50.1 to 54 Mc). It accommodates 5 front-panel crystals, selectable via a 6-position switch. An external VFO can also be connected and selected. The transmitter delivers a power input of 12 Watts to the final RF amplifier, utilizing crystal control and plate modulation.

The receiver is a sensitive superheterodyne circuit with 3 I.F. stages, dual tuned transformers, and a built-in noise limiter with full wave automatic series noise limiting and full AVC. An adjustable tuned RF Bandpass stage enhances sensitivity and selectivity while minimizing RF radiation. The receiver tunes the entire 6 meter band and includes an "S" meter for signal strength indication. A spotting switch allows precise tuning to the transmitted frequency. A variable "F" network facilitates antenna matching.

Power Supplies

The HE-45 can be operated from a 117-volt 60-cycle AC source or a 12-volt DC battery source.

• 117V 60 Cycle AC Source: Connect the supplied AC line cord (8-pin socket to transceiver) before plugging into the wall outlet.
• 12V DC Source: Connect the supplied battery cable (8-pin socket to transceiver) which includes an inline fuse holder and cigarette lighter plug. Polarity does not matter as the lighter receptacle connection grounds the cable to the "Hot" terminal.

Antenna Installation

The choice of antenna is crucial for optimal transmission. Select the antenna based on the specific application.

Fixed Antenna Installation

• For short-range communication, a base load or spiral whip antenna is adequate.
• A "ground plane" type antenna offers greater, more reliable coverage and is ideal for fixed-to-mobile operation.
• A directional "beam" type antenna with a rotator can extend range for point-to-point communication, especially under adverse conditions. A 4 or 5 element beam is recommended.

Antenna Height: Mount the antenna as high as possible. Choose a transceiver location that complements the antenna placement. Minimize lead-in cable length to reduce power loss.

Grounding: Use a water pipe ground wherever possible for improved operation.

Mobile Antenna Installation

A vertically polarized whip antenna is best suited for mobile service. Non-directional antennas are essential for mobile installations (cars, trucks, boats). Ensure a good earth ground and minimize ignition interference.

• Base-load whip antennas provide good results for short-range communications.
• A full quarter-wave vertical whip antenna offers greater range and reliability.

Both mobile whip types utilize the vehicle's metal body as a "ground plane". If the transceiver is not mounted to metal, run a separate ground wire. For boats without a steel hull, a ground plate is necessary for maximum efficiency. Consult a marine technician for proper grounding systems. Hi-gain horizontally polarized Halo antennas or coaxial antennas are also recommended for mobile operation.

Antenna Connections

Use RG-58/U cable terminated with a UHF type PL-259 connector for antenna lead-in. The transceiver has an SO-239 receptacle.

Lafayette Model HE-748WX Halo antenna or Model HE-801WX cowl mount universal 6 Meter Mobile antenna can be connected directly.

Ignition Interference

Standard vehicle ignition suppression is usually sufficient. For persistent issues, consult an auto radio repairman.

Boat Interference: Electrical noise from engines and equipment (generators, motors, pumps, fans) can disrupt reception. Gasoline engine ignition systems are the worst offenders. Filtering is required for these components.

• Ignition Systems: Use "spark shields" for gasoline marine engines.
• Auxiliary Generators: Install high-quality condensers (1.0 mfd recommended) at the generator armature terminal or brush holders. Connect the metal can to the generator frame. Never connect to the field terminal.
• Voltage Regulators: Have the unit cleaned and adjusted by an expert. If noise persists, install condensers on the armature terminal.
• Shaft Noise: If noise occurs when the engine is underway but disappears in neutral, suspect "shaft noise". Install phosphor bronze "fingers" with wiping contact to the shaft, connected to the engine block with a heavy wire.
• Diesel Engines: Generators require filtering similar to gasoline engines.
• Other Accessories: Fans, bilge pumps, electric toilets, etc., can be suppressed with condensers.

Mobile Installation of Transceiver

Choose a convenient location that does not interfere with driving. Mount the transceiver using the carrying handle (remove rubber bumpers for mounting holes) under the instrument panel or dashboard. Self-threading screws are provided. A perforated steel strap can provide additional back support.

The 12V DC power cable plugs into the cigarette lighter socket. A 10 Amp fuse is included. For permanent installations, remove the plug and connect directly to the battery source, preferably via the ignition switch. This ensures the transceiver is powered only when the ignition is on, preventing unauthorized use and battery drain. Ensure the "hot" or center lead of the plug is connected correctly to the ignition switch to avoid blowing the vehicle's fuse.

Maximum Power Transfer to Antenna

Use a dummy antenna for adjustments. Remove the two small plug buttons on the left side of the cabinet. Set the transceiver to transmit and the METER switch to the "lp" position.

1. Adjust the antenna output condenser (C2) fully tight, then back out 1/2 turn.
2. Adjust the antenna tank condenser (C1) for minimum "lp" meter reading (best dip) or maximum lamp brilliance.
3. Re-adjust C2 for an "lp" meter reading of approximately 60 to 65 MA.
4. Re-adjust C1 for maximum lamp brilliance or minimum meter reading (best dip).

Replace plug buttons after adjustments. The diagram for a simple dummy-load antenna is provided.

T.V. Interference Trap

A built-in series-resonant trap (L5) suppresses TV interference. If transmitting causes excessive TV interference, adjust the RF trap coil slug screw (L5) located at the rear of the cabinet, between the antenna input jack and power input receptacle.

To adjust: Tune a nearby TV to a lower channel with an operating station. If a "cross-hatch" or "wavy-line" pattern appears while transmitting, adjust L5 to minimize or eliminate this interference. This is typically needed when the transmitter antenna is close to a TV antenna.

Description of Controls

• VOLUME CONTROL AND POWER SWITCH: Varies audio output and switches power ON/OFF at the counterclockwise end.
• TUNING CONTROL: Operates the illuminated dial and tuning condenser via a reduction drive for accurate station selection. Receiver tuning does not affect transmission frequency.
• CRYSTAL SELECTOR SWITCH: Positions VFO, 1, 2, 3, 4, 5. Selecting a numbered position sets the transmitter to the frequency of the crystal in the corresponding socket. VFO position uses an external VFO. The transmitter is typically supplied with a crystal for 50.124 Mc (fundamental x 6). Additional fundamental crystals (within 0.01% accuracy) can be installed. Transmitting frequency = fundamental crystal frequency x 6.
• SPOT SWITCH: When ON, allows precise tuning to the transmitted frequency. Set to ON, meter switch to "S", and tune for maximum "S" meter gain using the internal crystal frequency. Normally kept in the OFF position.
• NOISE LIMITER: Reduces excessive noise (e.g., from auto ignition) that is louder than the received signal. May slightly reduce receiver sensitivity.
• RF PEAKING: Used after tuning in a station. Rock both tuning and RF Peaking knobs for best sensitivity.

Transmitting

1. Ensure the correct power supply cable is connected and the unit is properly grounded. Connect an antenna. Plug in the microphone.
2. Turn the transceiver ON. Set the tuning control to the desired operating frequency. The dial illumination indicates power. Use the "Spot" switch for same-frequency transmit/receive.
3. Set the CRYSTAL SELECTOR SWITCH to the desired transmit frequency position.
4. Set the METER SWITCH to "lp". The meter indicates final plate input power when the microphone button is pressed.
5. Hold the microphone 4-8 inches away and speak clearly. Shouting does not improve signal strength. The meter needle "flicker" indicates proper operation of speech amplifier and modulator circuits. Release the button to receive.
6. To check signal strength, set the METER switch to "S". The meter is calibrated in "S" units. The transmitter cuts off the receiver, so the "S" meter will read full scale when transmitting. Keep the meter switch in the "lp" position unless checking signal strength.
7. An external Variable Frequency Oscillator (VFO) can be connected via the VFO socket. Set the Selector switch to VFO.

Additional Crystals

The HE-45 is typically supplied with a 50.124 Mc crystal. Additional crystals for other 6-meter frequencies can be installed. The transmitting frequency is the fundamental crystal frequency multiplied by 6. Use fundamental crystals with 0.01% accuracy to avoid illegal operation. For TVI reduction, use crystals for frequencies between 50.15 Mc and 50.5 Mc.

Tube Replacement

Access tubes by removing the top shell cover. Remove the two screws on the top front panel and two screws on each side of the top shell. Slide the shell upward. Caution: Do not remove the base plate, as there is a shock hazard. Replacement tubes must match the original type numbers. A tube location diagram is on the license label on the bottom of the base plate. Reassemble in reverse order.

Technical Section

Tube Pin Functions

Removing the Lafayette HE-45 from Cabinet for Servicing

1. Remove the (2) screws holding the front panel to the top shell.
2. Remove the (2) screws on each side piece holding the bottom base to the top shell.
3. Slide the shell upward to remove the top shell.
4. Remove the (4) screws on the cabinet bottom holding the chassis to the bottom plate.
5. Remove the bottom base plate.

Transceiver Adjustments and Calibration

The following adjustment is necessary whenever a new crystal, whose frequency is more than 0.5 Mc different from the replaced crystal, is inserted.

Adjusting the Transmitter

Use a dummy antenna for transmitter tuning. A simple dummy load antenna sketch is provided. For those with proper equipment, a 52 ohm non-inductive load (15 watts minimum) can be connected to the antenna input socket. Measure voltage drop across the load with an RF voltmeter, or use a SWR bridge or RF voltmeter connected directly to the antenna.

1. Set crystal selector to position No. 1 or the position with the 50.124 Mc crystal.
2. Insert dummy load antenna or RF voltmeter into the antenna input socket.
3. Press and hold the microphone slide button to transmit.
4. Adjust antenna condenser (C2) fully tight, then back out 1/2 turn.
5. Adjust oscillator tripler coil slug (L1) for maximum RF voltmeter reading or lamp brilliance.
6. Adjust doubler coil slug (L6) for maximum RF voltmeter reading or lamp brilliance.
7. Adjust TANK condenser (C1) for maximum lamp brilliance or minimum meter reading (best dip).
8. Adjust C2 condenser for an "lp" meter reading of approximately 60 to 65 Ma.
9. Adjust C1 condenser for maximum lamp brilliance or minimum meter reading (best dip).
10. Momentarily switch the microphone button to receive, then back to transmit. If the lamp does not light or the RF voltmeter shows minimum reading, repeat adjustments. Ensure maximum oscillator drive with stability.

Note: Before adjustments, set crystal coil slug (L1) halfway in, doubler coil slug (L6) fully out, Tank condenser (C1) 3/4 way out. Meter switch on "lp" position.

Adjusting the Receiver I.F. Section

1. Turn Volume control fully ON (max clockwise).
2. Turn Noise Limiter control fully counterclockwise.
3. Connect an AC voltmeter (2.5 volt scale) between chassis and the speaker voice coil lug near the side of the chassis (or Pin #5 of the microphone socket).
4. Connect a signal generator to Pin #2 of the V2 Mixer tube (6EA8) via a 0.1 Mfd condenser. Connect the low side of the generator to chassis.
5. Set signal generator to 1650 Kc and peak IF transformers T3, T2, and T1 for maximum output meter gain.
6. Use a signal generator modulated 30% with 400 cycles, with the lowest possible output during these adjustments.

Adjusting the Receiver R.F. Section

1. Follow steps 1-3 from the Receiver I.F. section adjustment.
2. Turn RF peaking control so the RF peaking variable condenser is half meshed.
3. Connect a signal generator covering the 6 meter band (50.1 to 54 Mc) with spread frequencies for direct reading. A crystal-controlled signal generator is preferable. Connect the 52 ohm output impedance signal generator to the antenna input receptacle.
4. Adjust signal generator to 52 Mc and peak the top and bottom tuning slugs of L3 for maximum gain on the "S" meter or output meter.
5. Use a signal generator modulated 30% with 400 cycles, with the lowest possible output during these adjustments.

Receiver alignment is now complete. Do not adjust L2 in the input circuit, as it is factory set for proper transmitter operation.

Re-Calibration of the Transceiver Tuning Dial

1. Follow steps 1 and 2 under "Adjusting the Receiver I.F. Section".
2. Follow step 3 under "Adjusting the Receiver R.F. Section".
3. Adjust receiver tuning knob to 50 Mc.
4. Adjust signal generator to 50 Mc (crystal controlled preferred). Adjust receiver oscillator coil slug (L4) for maximum output on the meter. Note: There are two peaks; the lower peak is the image frequency; the upper peak is correct. Verify with a calibrated wavemeter or signal generator.
5. Adjust signal generator and receiving tuning knob to 53 Mc. Adjust Bandspread trimmer condenser (C4) for maximum gain on the output meter.
6. Re-check the 50 Mc calibration. If it has shifted, re-adjust L4 coil slug and C4 trimmer capacitor until calibration points are approximately equal. Check by noting where the signal appears on the transceiver's dial when the signal generator is set to 50-53 Mc.
7. Keep signal generator output as low as possible during RF adjustments.
8. Re-mount the transceiver chassis into the cabinet using the reverse procedure of removal.
9. Before mounting the top cabinet shell, check dial calibration. If shifted, repeat step 6.

Note: If no AC output meter is available, the receiver's "S" meter can be used. Set meter switch to "S" position and keep generator signal input low enough to obtain a 1/2 meter scale reading.

Note: When performing steps 4-6, rock the RF Peaking variable condenser (C3) simultaneously for maximum gain on the "S" meter or output meter.

If the 1st IF amplifier tube (V3-12BA6) or 2nd IF amplifier tube (V4-A 6U8A/6EA8) has been replaced and the meter pointer is not on zero with no signal input, re-adjust the meter zero pot (located beneath the vibrator socket on the back chassis apron) for electrical zero. Adjust mechanical meter zero with the transceiver off.

R.F. Power Output Meter

In transmit position, record the current on the 100 Ma meter when the meter switch is in the "lp" position (typically 60-65 Ma). Measure the positive DC voltage at the low side of the transmitter output coil (L2) (typically 240 V.D.C.).

Calculate plate input power: (Plate Voltage x Plate Current in Amperes) = Plate Input Power. Convert milliamperes to amperes by moving the decimal three places to the left.

Shipping Instructions

If the unit requires return for adjustment or service:

• Attach a tag with your name, complete address, and a description of the difficulties encountered.
• Wrap the unit in heavy paper. Place it in a carton large enough to allow at least three inches of shredded paper or excelsior cushioning on all sides.
• Mark the carton "FRAGILE" and address it to:

LAFAYETTE RADIO ELECTRONICS CORP.
111 JERICHO TURNPIKE
SYOSSETT, LONG ISLAND

Include your own name and address on the carton. Ship via prepaid express. The unit will be returned via express collect. The carrier may disclaim responsibility for damage caused by improper packing.