AOR SDU-5000 Spectrum Display Unit Operating Manual

I. General

For years, professionals have used spectrum display units (SDU) and spectrum analyzers to intercept elusive signals. The SDU-5000 offers this capability at a more accessible price point. It allows users to view a 10MHz window of the spectrum. By moving the SDU cursor left or right, or pressing the PEAK key, users can pinpoint a signal of interest and instantly read its frequency and signal level. This feature is enhanced when used with the AR-3000A general coverage receiver, enabling data storage on disk for later analysis via a PC.

II. Technical Highlights

• First SDU using a 16-color LCD screen.
• Composite video output (NTSC or PAL) for larger screens or VCR recording/playback.
• Easy-to-operate, menu-driven system.
• 100% compatible with AR-3000A with 10.7MHz IF (direct control features are limited).
• Direct frequency and level digital presentation on screen with AR-3000A.
• Dual resolution: Wide 30KHz / Narrow 5KHz.
• High frequency accuracy using Direct Digital Synthesizer (DDS).
• Displays average, peak, and maximum signal levels, features typically found only in very expensive spectrum analyzers.

III. Specifications

IV. Accessories Supplied

1. AR-3000A control cable.
2. DC power supply cable.
3. Operating Manual.

V. Control, Display and Connectors

This section describes the control and display of the SDU-5000.

A. Front Panel

The front panel features:

• Power Switch: Press once to turn on, press again to turn off.
• Color LCD Display: Shows spectrum data.
• Keyboard: Contains 24 control keys.

Key layout:

CF SPAN RBW
ATT MODE STEP PEAK MKR
CONF 1 2 3
4 5 6
7 8 9
INF 0 .
PgUp PgDn ESC ENT

B. Rear Panel Connectors

• DC 12V: For DC 12V power supply.
• RX Control: Connects to AR-3000A with a special cable.
• PC I/F: RS-232C port for PC connection.
• Video Out: Connects to an external video monitor.
• Video Select: Selects NTSC or PAL for external monitor.
• RF IN: 10.7MHz input from receiver.

C. Side Panel

• Brightness Control: Adjusts the brightness of the LCD display.

VI. Precautions

A. Power Supply Requirement

The SDU-5000 requires an external DC power supply. Use a well-regulated DC power supply capable of delivering a minimum of 1,000mA (1A). Consult the store where the unit was purchased for recommendations.

Refer to Figure 1 for DC jack polarity.

Figure 1: DC JACK Polarity

Center +
Shield -
View from rear panel

B. Location

Do not use or leave the SDU-5000 in direct sunlight. Avoid locations with excessive heat, humidity, dust, and vibration. Always handle the SDU-5000 with care.

C. Looking After Your SDU-5000

Keep the SDU-5000 free from dust and water. Use a soft, dry cloth to gently wipe the unit clean. Never use chemicals such as benzene or thinners, as they can damage parts.

D. Color LCD

The internal LCD display is made of glass; avoid strong shocks and dropping.

E. Brightness of LCD

The brightness of the LCD display is adjustable via a control on the side panel.

VII. Setup and Connection

A. Power Supply

Ensure the power switch of the SDU-5000 is turned off before connecting the power supply with the supplied cable.

B. AR-3000A Modification

To connect the SDU-5000 to an AR-3000A receiver, the AR-3000A requires modification. This modification requires special skill and proper tools. Some dealers offer AR-3000A units with this modification already performed. If your AR-3000A is not modified, consult the following companies for proper modification:

1. U.S.A: Electronic Equipment Bank, Inc., 323 Mill Street, Vienna VA 22180. Tel: (703)938-3350, Fax: (703)938-6911.
2. Europe: AOR UK, Adam Bede High Tech Center, Derby Road, Wirksworth, Derbys. DE4 4BG. Tel: 01629 82596, Fax: 01629 825927.

The following sections describe the operation of the SDU-5000 with a properly modified AR-3000A receiver.

C. Connection (AR-3000A with IF modification)

1. Both SDU-5000 and AR-3000A should be turned OFF.
2. Connect the AR-3000A's remote terminal to the RX CONTROL of the SDU-5000 using the special cable provided with the SDU-5000.
3. Connect the AR-3000A's IF OUTPUT to the RF IN of the SDU-5000.
4. Turn on the AR-3000A power.
5. Turn on the remote switch of the AR-3000A.
6. Turn on the SDU-5000 power.
7. The SDU-5000 will start to control the AR-3000A via RS-232C.

If the SDU-5000 cannot control the AR-3000A, the display will show a "connect error" message, and the unit will automatically select other receivers mode.

D. Connection (Other receivers with 10.7MHz output)

The SDU-5000 is designed to operate with any receivers that have a 10.7MHz IF output, though some features may be limited.

1. Both SDU-5000 and the receiver should be turned OFF.
2. Connect the receiver's IF output to the RF IN of the SDU-5000.
3. Turn the receiver power ON.
4. Turn the SDU-5000 power ON.

It is necessary to set RF Gain, Display Mode, and Span according to the instructions provided in this manual.

E. Connection (External Display Monitor)

The SDU-5000 provides switchable NTSC or PAL video output. Follow these steps:

1. SDU-5000, receiver, and external monitor should be turned OFF.
2. Connect VIDEO OUT to VIDEO IN of the monitor.
3. Select NTSC or PAL according to the monitor type. Most European users prefer PAL, while North American users typically use NTSC.
4. Turn on the monitor power.
5. Turn on the receiver power.
6. Turn on the SDU-5000 power.

NOTE: If the NTSC-PAL switch is in the PAL position, the internal LCD is disabled.

VIII. Operation

A. Basic Key Operation

The SDU-5000 is controlled by its keyboard. The following describes common operations:

• 1. Parameter Setting: Set operation parameters like Center Frequency, Span Width, and Resolution Bandwidth.
• 2. AR-3000A Control: Control the AR-3000A's Attenuator, Mode, and Step frequency.
• 3. Configuration: Set and read operating configurations such as Receiver type, RF Gain, Plot Mode, and Display Mode.
• 4. Analysis Function: Set display functions like Averaging, Maximum Hold, Peak Detect, and Marker.
• 5. Marker and Tuning: Move the marker and tune the center frequency.

Special Function Keys:

• ENT: Completes sequence of various data entry.
• ESC: Aborts the sequence.
• PgDn: Moves the cursor down and tunes the center frequency. When setting parameters or selecting menus with numeric keys, this key cancels the previous input.

Numeric Keys (0-9 and .):

Used for entering frequency, span, step, and selecting menu items.

B. Setting Parameters

1. Center Frequency

a) Direct Entry

1. Press the CF key.
2. The display shows "Center Frequency?".
3. Enter the center frequency in MHz using the numeric keys.
4. Press the ENT key.

Example: 81.25MHz

CF 7 SPAN 8 CONF 1 MODE 5 ENT 2

b) Step Adjustment

Set the AR-3000A for a specific frequency increment. Use the arrow keys (PgDn, PgUp) to move the center frequency one step lower or upper.

NOTE: The marker should be OFF when using this feature.

c) Scrolling

Scroll the center frequency up or down by half of the frequency span.

• Press PgDn to scroll the center frequency lower.
• Press PgUp to scroll the center frequency upper.

d) Marker

If a marker is displayed, pressing the 2 key switches the marker frequency to the center frequency. This allows instantaneous movement to a desired frequency based on the display. Pressing the 2 key again shifts the marker frequency to the center frequency, making it the new center frequency.

To exit marker mode, press the ESC key.

2. Frequency Span Width

1. Press the SPAN key.
2. The display shows "Span Frequency?".
3. Enter the frequency span width in KHz using the numeric keys.
4. Press the ENT key.

Example: 5MHz

SPAN 8 5 MODE 5 INF 0 ENT 0

3. Resolution Bandwidth

Two resolutions of bandwidth are provided: 5kHz and 30kHz.

1. Press the RBW key.
2. The display shows the menu.
3. Enter the selected menu number using the numeric keys.
4. Press the ENT key.

Example: 5kHz

RBW 9 CONF 1 ENT

C. Controlling AR-3000A

When the AR-3000A is used as a companion receiver, Attenuator, Mode, and Step Frequency can be set from the SDU-5000.

1. Attenuator

1. Press the ATT key.
2. The display shows the menu.
3. Enter the selected menu number using the numeric keys.
4. Press the ENT key.

Example: ATT On

ATT 4 MODE 5 ENT

2. Mode

1. Press the MODE key.
2. The display shows the menu.
3. Enter the desired mode using the numeric keys.
4. Press the ENT key.

Example: NFM

MODE 5 CONF 1 ENT

3. Step Frequency

1. Press the STEP key.
2. The display shows "Step?".
3. Enter the step frequency in KHz using the numeric keys.
4. Press the ENT key.

Example: 12.5kHz

STEP 6 CONF 1 CF 7 MODE 5 ENT

D. Setting Operating Configuration

To utilize maximum features of the SDU-5000, operating configurations can be set and retained. The configurable settings include: RECEIVER TYPE, RF GAIN, PLOT MODE, and DISPLAY MODE.

1. Receiver Type

1. Press the CONF key.
2. The display shows the configuration menu.
3. Press the 1 key (or ENT then 1).
4. The display shows the provided receiver list.
5. Enter the number corresponding to the desired receiver using the numeric keys.
6. Press the ENT key.

Example: AR-3000A

CONF 1 ENT 1 CONF 1 ENT 2

NOTE: If the SDU-5000 cannot control the AR-3000A, it will display a "connect error" message and automatically switch to "other receivers mode".

2. RF Gain

RF Gain can be chosen from Low (-10dBm) or High (-40dBm).

1. Press the CONF key.
2. The display shows the configuration menu.
3. Press the 2 key (or ENT then 2).
4. The display shows the RF Gain select menu.
5. Enter the number corresponding to the desired setting using the numeric keys.
6. Press the ENT key.

Example: Low (-10dBm)

CONF 1 RCF 2 ENT CONF 1 ENT

3. Plot Mode

Plot type can be selected from PAINT or OUTLINE.

1. Press the CONF key.
2. The display shows the configuration menu.
3. Press the 3 key (or ENT then 3).
4. The display shows the plot mode select menu.
5. Enter the number corresponding to the desired mode using the numeric keys.
6. Press the ENT key.

Example: OUTLINE

CONF 1 PED ENT 3 MARCF 2 ENT

4. Display Mode

This function enables the SDU-5000 to display frequency in normal (left is lower frequency from center cursor) or reverse (left is higher frequency for the center cursor). When the receiver type is set to AR-3000A, the SDU-5000 selects the proper display mode automatically.

1. Press the CONF key.
2. The display shows the configuration menu.
3. Press the 4 key (or ENT then 4).
4. The display shows the display mode select menu.
5. Enter the number corresponding to the desired mode using the numeric keys.
6. Press the ENT key.

Example: Reverse Direction

CONF 1 ATT 4 ENT 2

5. Display Current Configurations

To verify the SDU-5000's current configurations, use the INF 0 key. The display shows current configurations until another key is pressed.

E. Analysis

The SDU-5000 provides professional features to analyze receiving signals. Four analyzing tools are available: AVERAGING, MAXIMUM HOLD, MARKER, and PEAK DETECT.

1. Averaging

This feature displays the signal level based on a mathematical formula. The sampling rate can be set from 2 to 32. It is useful for determining the average signal level or displaying a constant signal without showing instantaneous noise.

1. Press the AVR key.
2. The display shows "AVR. (2-32)".
3. Enter the sampling rate using the numeric keys.
4. Press the ENT key.
5. The display shows the current sampling number on the top right corner of the screen.

To exit this function, press the ESC key.

2. Maximum Hold

This feature displays the maximum signal level. It is useful for identifying instantaneous or intermittent signals. The screen holds the level until a stronger signal is received.

1. Press the MAX key.
2. The display shows "MAX".

To exit this function, press the ESC key.

3. Marker

To enable the marker feature, press the MKR key. The screen displays "Marker" and a "+" symbol on the signal. The marker's signal level and frequency are shown on the display. Use the arrow keys (PgDn, PgUp) to move the marker. Pressing the 2 key shifts the marker frequency to the center frequency, making it the new center frequency.

To exit marker mode, press the ESC key.

4. Peak Detect

When the PEAK key is pressed, the SDU-5000 stops updating the signal input, and a red "+" symbol appears at the strongest signal peak. Pressing the PEAK key once moves the marker to the next strong signal peak. Pressing the 2 key moves back to the previous position. To tune the signal at the marker position, press the 2 key again to shift the marker frequency to the center frequency.

To exit peak detect mode, press the PEAK key again.

IX. PC I/F

The SDU-5000 is capable of remote control via its 9-pin female D-type rear connector (PC I/F) using a simple RS-232C cable without needing an interface.

A. Connection

Connection to an IBM PC 25-pin D-type serial port requires the following connections:

For a three-wire hookup, connect the RTS and CTS lines together (Pins 7 & 8) at the SDU-5000 end of the cable.

B. Communication Parameters

If using a terminal driver, configure the following communications parameters:

• Baud rate speed: 9600 BPS
• Stop bits: 2 Bits
• Data bits (length): 8 Bits
• Parity: None
• X parameter: On

C. Commands

The SDU-5000 provides remote control command functions similar to key operations.

D. Format1 (Contents of the Configurations)

When the SDU-5000 receives the "H" command from the PC, it sends current configuration data in the following format:

Example: R1 G1 D1 B2 C80.00000 S2000 A0 M3 T12.5 [CR][LF]

E. Format2 (Contents of the read out data)

When the SDU-5000 receives the "I" command from the PC, it sends 161 pairs of signal level and frequency data in the following format:

"/"[CR][LF] Start of data block

"F" + Frequency(MHz) + "," + "L" + level(dBm) + [CR][LF]

↑ x161 pairs of data

"/"[CR][LF] End of data block

Example:

/[CR][LF]

F80.0000,L-75[CR][LF]

F80.1000,L-66[CR][LF]

F80.2000,L-45[CR][LF]

/[CR][LF]

F. Format3 (Contents of the read out marker)

When the SDU-5000 receives the "J" command from the PC, it sends the signal level and frequency at the marker position with the following format:

"f" + Frequency(MHz) + "," + "l" + level(dBm) + [CR][LF]

Example:

f80.0000,l-76[CR][LF]

Supplement Manual and Notes

Notes for the SDU5000 (Rev 1.3)

This supplement provides updates and additional information for the SDU5000.

Compatibility and Setup

The SDU ROM permits operation with AOR AR3000A, ICOM IC-R7000, IC-R7100, IC-R9000, and other receivers with a 10.7 MHz IF output. A small modification may be required for AOR receivers for compatibility. For ICOM receivers, the CT17 optional interface is required, and the ICOM receiver must be configured for remote control.

ICOM Receiver Setup Requirements:

• Baud rate: 9600 bps
• Frequency data: 5 Bytes
• Transceive: ON
• Address default: IC-R7000 (08H), IC-R7100 (34H), IC-R9000 (2AH)

Example setup for ICOM IC-R7100:

• Transceive ON: On the ICOM receiver, press and hold "3" and "ENT", then switch power ON. Switch receiver OFF.
• Baud rate 9600: On the ICOM receiver, press and hold "5" and "ENT", then switch power ON. Switch receiver OFF.

The receiver must be configured and switched ON before the SDU5000 for a valid RS232 connection. Note: ICOM receiver output levels are approximately 10-15dB below AOR receiver levels.

Troubleshooting and Behavior

• If connection is lost, use "CONF" to re-select the correct receiver.
• If a connection cannot be established, switch off the SDU5000, unplug the 12V DC feed for 10 seconds, then reconnect and try again.
• False indications below 0 MHz may occur (negative frequency values).
• A small false signal may appear near the center frequency (455kHz) due to the receiver's internal 455 kHz IF. This is normal.
• When tuning in channelized bands, ensure the correct STEP size is selected (e.g., 9kHz for medium wave).
• Frequency display may be off by 5-6 kHz depending on step size, resolution, and span. Resetting the center frequency reduces this error. This is most noticeable when using the "marker".
• The graticule has 16 steps per division, totaling 160 steps across the screen. Frequency shift per marker movement is calculated as: (SPAN in kHz) / 10 / 16. For a 10 MHz span, this is 62.5 kHz per step.
• Due to AGC effect, peak trace may reduce towards the center frequency. Measurements may be more accurate away from the center. Level change can be 10-15 dB depending on AGC. For best accuracy, switch AGC "off" on the AR3000A/3000 when measuring at the center frequency.

ICOM ICR8500 Setup

Set the R8500 as an ICR7100 via the ICOM initial set mode. Set baud rate to 9600 and address to 34h. The supplied RS232 cable is ready for use.

New Version Features

• Support for AR3000A, AR5000, and ICOM receivers (IC-R7100, R7000, R9000).
• When AR5000 is used, Center Frequency renews automatically every second.
• Allows frequency and mode change from ICOM receivers.
• Added "Stepping frequency set" and "Step-up/Step-down" features for other receivers.
• Added "Marker Center" feature for other receivers.
• Added "K" command for high-speed data downloading.

Specification & Operating Procedure Changes

• Receiver Type: AR5000, AR3000A, IC-R7000, IC-R7100, IC-R9000 can be selected. Default is "OTHER".
• Center Frequency Setting: Minimum step is 10Hz for AR5000, 50Hz for others. Frequencies below 50Hz increment are rounded up. ICOM receivers ignore frequencies below 100Hz.
• Attenuator Setting: Available for AR5000 and AR3000A. 10dB Attenuator is chosen when receiver is AR5000. Relations between ATT and Center Frequency for AR5000 are detailed in Table -1.
• Step Frequency Setting: For AR5000, 10Hz increments up to 999.99kHz. For others, 50Hz increments up to 999.95kHz.
• Operating Mode: For AR5000, modes include WFM, NFM, AM, LSB, USB, CW, AUTO. For ICOM, if mode is not supported, "NFM" is displayed.
• Center Frequency Setting and MKR>CF for other receivers: Setting range depends on "SPAN".
• K Command (High speed data down-loading): SDU downloads level status by format: "K" + "CR,LF" | DATA (00h-FFh) | "K" + "CR, LF". Data range depends on RF gain (LOW: -60dBm to -10dBm, HIGH: -90dBm to -40dBm).
• Change in H Command: Configuration information command modified.
• Operating with AR5000: Details connection and setting procedures.
• Operating with ICOM receivers: Details setting ICOM receivers, connection, and configuration.
• Precaution in combination of AR5000 and SDU5000: Discusses automatic renewal of Center Frequency, reception mode setting, IF output setting, and step adjustment.

Remember, although not a low-cost product, the SDU5000 is a fraction of the price of a dedicated spectrum analyzer.