Manuals+

ICOM IC-28A/E VHF FM Transceiver Instruction Manual

Congratulations on choosing this technically-advanced ICOM product. The IC-28A/E VHF FM transceiver is the latest addition to the ICOM system of Amateur radio equipment. It includes provision for the newly developed Digital Code Squelch method of communicating, utilizing digital techniques to reduce inconvenience on crowded Amateur bands. ICOM products are supported by a world-wide network of authorized service centers and dealers.

Table of Contents

IC-28A/E ACCESSORIES SUPPLIED

SECTION 1 SPECIFICATIONS

1 - 1 GENERAL

Frequency coverageIC-28A: 144.00 ~ 148.00 MHz
IC-28A Australia version: 144.00 ~ 148.00 MHz
IC-28E: 144.00 ~ 146.00 MHz
IC-28E Italy, Spain versions: 144.00 ~ 148.00 MHz
Frequency resolutionIC-28A: 5, 10, 15, 20 or 25 kHz (programmable)
IC-28E: 12.5 or 25 kHz (programmable)
Frequency controlCPU based 5 kHz (or 6.25 kHz) step digital PLL synthesizer. Simplex and semi-duplex capability (programmable offset).
Memory channels21 channels
Usable temperature range-10°C ~ +60°C (+14°F ~ +140°F)
Power supply requirement13.8 V DC ±15% (negative ground). AC power supply is available for AC operation.
Current drain (at 13.8 V DC)Transmit: HIGH (25W) Approx. 6.0A, LOW (5W) Approx. 3.0A
Receive: Max. audio output Approx. 800mA, Squelched Approx. 450mA
Antenna impedance50 ohms unbalanced
Dimensions140(140)mm(W) x 50(50)mm(H) x 133(148.5)mm(D) (Bracketed values include projections)
Weight0.95 kg

1-2 TRANSMITTER

Output powerHIGH 25W, LOW 5W
Emission mode16K0F3E
Modulation systemVariable reactance frequency modulation
Max. frequency deviation±5.0 kHz
Spurious emissionsMore than 60 dB below carrier
Microphone600 ohm electret condenser with push-to-talk and scanning switches (IC-28E: 1750 Hz tone burst switch)

1 - 3 RECEIVER

Receive systemDouble-conversion superheterodyne
Modulation acceptance16K0F3E
Intermediate frequencies1st 17.2 MHz, 2nd 455 kHz
SelectivityMore than 12.5 kHz at -6 dB, Less than 25.0 kHz at -60 dB
SensitivityLess than 0.18 µV for 12 dB SINAD
Audio outputMore than 2.4 watts at 10% distortion with 8 ohm load
Audio output impedance4 ~ 8 ohms

SECTION 2 FEATURES

SECTION 3 CONTROL FUNCTIONS

3.1 FRONT PANEL

(1) VOLUME CONTROL/POWER SWITCH [VOL/PWR]: Push to turn the power ON and OFF. Turn clockwise to increase the audio level.

(2) SQUELCH CONTROL/CHECK SWITCH [SQL/CHK]: Quiets noise when no signals are received. Turn clockwise until the T/R LED goes out. Push to monitor transmit frequency in duplex mode.

(3) VFO/MEMORY READ SWITCH [VFO/MR]: Push to select either the VFO mode or the MEMORY mode. "M" appears on the LCD when MEMORY mode is selected.

(4) SET SWITCH: Multi-function switch. In VFO mode, used for programming subaudible tone, transmit offset, and tuning step size. In MEMORY mode, controls the skip function.

(5) TUNING CONTROL: In VFO mode, increases/decreases operating frequency. Used with SET SWITCH for programming. In MEMORY mode, selects memory channels.

(6) UP/DOWN SWITCHES: In VFO mode, changes frequency in 1 MHz increments. In MEMORY mode, steps through memory channels. Holding down initiates scan.

(7) TONE SWITCH (IC-28A U.S.A. version) / CALL SWITCH (except U.S.A. version):

(8) WRITE SWITCH: In VFO mode, stores displayed frequency in memory. In MEMORY mode, transfers memory contents to VFO.

(9) HIGH/LOW SWITCH [HI/LO]: Selects HIGH (25W) or LOW (5W) transmit output power. "LOW" appears when selected.

(10) TRANSMIT/RECEIVE INDICATOR [T/R]: Red LED indicates transmit mode, green LED indicates receive mode (squelch open). Off when squelch is closed.

(11) DISPLAY DIMMER SENSOR: Measures ambient light to control display backlighting intensity.

(12) DUPLEX SWITCH [DUP]: Selects simplex or duplex operation (DUP- for lower transmit frequency, DUP+ for higher transmit frequency).

(13) MIC CONNECTOR: Connects the supplied microphone.

(14) T/D.SQL SWITCH: Activates optional squelch systems (Tone Squelch or Digital Code Squelch).

LCD READOUT Indicators:

3-3 REAR PANEL

SECTION 4 INSTALLATION

4 - 1 MOBILE INSTALLATION

LOCATION

Choose a location accessible from the driver's seat, avoiding areas with extreme temperature variations or direct airflow. Ensure the mounting does not hinder vehicle operation. Secure the transceiver using the supplied bracket, allowing for approximately 18 degrees of angle adjustment for optimal viewing.

INSTALLATION

Mount the transceiver securely using the bracket and supplied hardware. Connect the unit directly to a 12 V battery, observing correct polarity (RED to POSITIVE, BLACK to NEGATIVE). Do not use the cigarette lighter for power.

ANTENNA

Antenna performance is crucial. Select a high-quality antenna and install it according to the manufacturer's recommendations. Consider gutter-mount, bumper-mount, trunk-mount, or roof-mount options for optimal radiation patterns.

COAXIAL CABLE

Use large diameter 50 ohm coaxial cable for reduced signal loss, especially important in the VHF spectrum.

MICROPHONE

Connect the supplied electret condenser microphone to the front panel jack. Optional microphones are available.

EXTERNAL SPEAKER

An external speaker jack is provided. Connect a 4 ~ 8 ohm speaker if needed; this disconnects the internal speaker. The SP-10 speaker is recommended for mobile use.

4 - 2 FIXED INSTALLATION

POWER SUPPLY

A stable AC power supply with a protective circuit is required. The PS-45 AC Power Supply with the OPC-102 interface cable is recommended.

ANTENNA

For fixed locations, a 50 ohm directional antenna is recommended for reliable communication. Choose an antenna suited to your needs and consider using low-loss coaxial cable (e.g., RG-8A over RG-58C) to minimize signal loss over longer feedline lengths.

COAXIAL CABLE

Proper coaxial cable installation involves stripping the cable, tinning the shield and center conductor, and soldering the connector body. Ensure the coupling ring is screwed onto the connector body.

MICROPHONE

For base operation, recommended optional microphones include the SM-8 Desk Microphone and the SM-10 Compressor/Graphic Equalizer Microphone.

EXTERNAL SPEAKER

The SP-7 Base Speaker is recommended for fixed location operation, in addition to the SP-10.

SECTION 5 OPERATION

5 - 1 BASIC OPERATION

RECEIVING

  1. Push the VOL/PWR CONTROL to turn the unit ON.
  2. Turn the VOL/PWR CONTROL clockwise to adjust the volume level.
  3. Slowly turn the SQL/CHK CONTROL clockwise until the received noise is quieted (T/R INDICATOR goes out). This ensures the squelch circuit is properly set.
  4. Select the desired operating frequency using the TUNING CONTROL or the UP/DN SWITCHES on the microphone. If in MEMORY mode, push the VFO side of the VFO/MR SWITCH to select VFO mode.

When a signal is received, the T/R INDICATOR lights green, the S/RF INDICATOR shows signal strength, and audio is heard.

SELECTING A FREQUENCY

(A) USING THE TUNING CONTROL:

  1. Select VFO mode using the VFO/MR SWITCH.
  2. Set the tuning step size by pushing the SET SWITCH repeatedly until the TS INDICATOR flashes, then use the TUNING CONTROL to select the desired step size (5, 10, 15, 20, or 25 kHz for IC-28A; 12.5 or 25 kHz for IC-28E).
  3. Use the TUNING CONTROL to select the exact frequency.

(B) USING THE MICROPHONE:

  1. Select the VFO mode and set the tuning step size as described above.
  2. Push the UP or DN SWITCH on the microphone to change frequency. Holding the switches down initiates frequency scanning.

TRANSMITTING

  1. Ensure your transmit frequency is not in use.
  2. Push and hold the PTT SWITCH on the microphone. The T/R INDICATOR lights red.
  3. Speak into the microphone at a normal voice level. Avoid holding the microphone too close or speaking too loudly to prevent distortion.
  4. Release the PTT SWITCH to stop transmitting. The T/R INDICATOR goes out, and the receiver mode is restored.

SELECTING OUTPUT POWER

Push the HI/LO SWITCH to toggle between HIGH (25W) and LOW (5W) transmit power. The "LOW" indicator appears on the display when LOW power is selected.

MEMORY READING

To select a memory channel:

  1. Push the MR side of the VFO/MR SWITCH to select MEMORY mode ("M" appears on the display).
  2. Use the TUNING CONTROL or the UP/DN SWITCHES (front panel or microphone) to step through the memory channels and view their contents.

MEMORY PROGRAMMING

To store information into a memory channel (e.g., 144.950 MHz into memory channel 10):

  1. Select the desired memory channel (e.g., 10) using the MEMORY READING procedure.
  2. Push the VFO side of the VFO/MR SWITCH to enter VFO mode.
  3. Select the desired operating frequency (e.g., 144.950 MHz). You can also program duplex and memory skip information at this stage.
  4. Push and hold the WRITE SWITCH for approximately 0.5 seconds until three short tones are heard, confirming the data is stored.

MEMORY CHANNEL TO VFO TRANSFERS

To transfer memory channel contents to the VFO:

  1. Select the desired memory channel.
  2. Push and hold the WRITE SWITCH for approximately 0.5 seconds until three short tones are heard. The "M" indicator disappears, and the transceiver switches to VFO mode with the transferred frequency displayed.

5 - 3 SCAN FUNCTIONS

FREQUENCY SCANNING

Frequency scanning searches the entire band based on the programmed tuning step size. The receiver stops on frequencies with signals.

  1. Select VFO mode.
  2. Ensure the microphone SCAN SWITCH is ON.
  3. Push and hold the UP or DN SWITCH on the microphone for about 0.5 seconds to start scanning. The decimal point on the display blinks.
  4. Scanning stops on a signal. It resumes after the signal disappears or after a set delay.
  5. Push the UP or DN SWITCH to cancel the scan.

MEMORY CHANNEL SCANNING

Memory channel scanning checks all programmed memory channels repeatedly.

  1. Select MEMORY mode.
  2. Ensure the microphone SCAN SWITCH is ON.
  3. Push and hold the UP or DN SWITCH on the microphone to start and stop the scan.

MEMORY SKIP FUNCTION

To exclude a memory channel from scanning:

  1. Select MEMORY mode.
  2. Select the channel to be skipped.
  3. Push the SET SWITCH. The SKIP INDICATOR appears.
  4. Push the SET SWITCH again to cancel the skip function.

5 - 4 DUPLEX MODE

DUPLEX PROGRAMMING

The duplex mode allows for different transmit and receive frequencies, often used with repeaters.

  1. Select VFO mode.
  2. Push the SET SWITCH repeatedly until the OW INDICATOR flashes.
  3. Select the transmit offset: "F" for fixed 600 kHz offset, or "P" for programmable offset. Use the TUNING CONTROL to set the desired offset value (0 to 7.99 MHz) if "P" is selected.
  4. Push the VFO side of the VFO/MR SWITCH.
  5. Push the DUP SWITCH to select DUPLEX (-) (transmit frequency lower) or DUPLEX (+) (transmit frequency higher). Simplex mode is when neither DUP indicator appears.
  6. Push the SQL/CHK CONTROL to monitor the transmit frequency.

SUBAUDIBLE TONE ENCODER (IC-28A U.S.A. version)

This feature allows access to repeaters requiring a subaudible tone.

PROGRAMMING THE SUBAUDIBLE TONE ENCODER

To program a tone (e.g., 88.5 Hz in tone memory 3):

  1. Select VFO mode.
  2. Push the SET SWITCH repeatedly until the TONE INDICATOR flashes.
  3. Use the DOWN/UP SWITCH to select the tone memory (1, 2, or 3).
  4. Turn the TUNING CONTROL to select the desired tone number (refer to the SUBAUDIBLE TONE FREQUENCY CHART).
  5. Select VFO mode.
  6. Select the duplex mode.
  7. Push the TONE SWITCH to activate the tone encoder. The "TONE" indicator appears.

1750Hz TONE BURST FUNCTION (IC-28E)

To access repeaters requiring a 1750 Hz tone burst:

  1. Adjust the IC-28E for duplex operation.
  2. Push and release the microphone TONE SWITCH to generate the tone burst (approx. 300 milliseconds).
  3. Push the PTT SWITCH and transmit.

5 - 5 CALL CHANNEL FUNCTION (except U.S.A. version)

USING THE CALL FUNCTION

  1. Push the CALL SWITCH to select the call function. The "C" symbol appears on the display.
  2. Push the CALL SWITCH again to release the call function.

PROGRAMMING THE CALL CHANNEL

Program memory channel 21 using the same procedure as for other memory channels (SECTION 5 - 2 MEMORY PROGRAMMING).

5 - 6 MICROPHONE

5 - 7 BACKUP BATTERY

A lithium battery provides backup for the internal microcomputer memory when external power is removed. It is rated for over five years of operation. Monitor performance and replace if display malfunctions occur after five years.

5 - 8 RESETTING INTERNAL MICROCOMPUTER (CPU)

If the LCD displays erroneous information, turn off the power, wait, and turn it back on. If the problem persists, reset the CPU:

  1. Turn the power ON.
  2. Insert a non-metallic probe into the RESET HOLE on the bottom cover and push the RESET SWITCH.

After resetting, memory channels must be reprogrammed. Default settings are:

TRANSCEIVERVFO FREQUENCY & MEMORY CHANNELSTUNING STEPSOPERATING MODETRANSMIT OFFSETTRANSMIT OUTPUT POWER
IC-28A146.010 MHz15 kHzVFO/SIMPLEX600 kHz25 W
IC-28A (Australia version)145.000 MHz25 kHzVFO/SIMPLEX600 kHz25 W
IC-28E145.000 MHz25 kHzVFO/SIMPLEX600 kHz25 W

5 - 9 OPTIONAL UNITS

PROGRAMMING THE UT-28 DIGITAL CODE SQUELCH UNIT

AQS (Amateur Quimmatic System) uses digital code squelch. The group code must be programmed identically in transmitting and receiving radios.

  1. Push the T/D.SQL SWITCH. "D.SQL" appears.
  2. Push the SET SWITCH. "D.SQL" flashes.
  3. Use DOWN/UP SWITCH to select group code memory (1-3).
  4. Push SET SWITCH again. "AQS" flashes, "D.SQL" disappears.
  5. Use TUNING CONTROL and DOWN/UP SWITCH to set the five-digit group code.
  6. Push SET SWITCH.
  7. Use DUPLEX SWITCH to select simplex mode.

PROGRAMMING THE UT-29 TONE SQUELCH UNIT

  1. Push the T/D.SQL SWITCH. "D.SQL" and "TONE" appear.
  2. Push the SET SWITCH. "D.SQL" and "TONE" flash.
  3. Use DOWN/UP SWITCH to select tone memory (1-3).
  4. Turn TUNING CONTROL to choose the required tone number (refer to chart).
  5. Push SET SWITCH.

OPTIONAL SQUELCH UNIT OPERATION

Activate the squelch unit by pushing the T/D.SQL SWITCH. Operate normally. Turn the unit OFF with the T/D.SQL SWITCH to program settings. Confirm compatible group codes for UT-28. Scanning is not available with UT-28 activated.

SUBAUDIBLE TONE ENCODER FREQUENCY CHART

(For IC-28A U.S.A. version with repeaters)

TONE NUMBERFREQUENCY (Hz)TONE NUMBERFREQUENCY (Hz)TONE NUMBERFREQUENCY (Hz)
0167.015110.929179.9
0271.916114.830186.2
0374.417118.831192.8
0477.018123.032203.5
0579.719125.333210.7
0682.520131.834218.1
0785.421136.535225.7
0888.522141.336233.6
0991.523146.237241.8
1094.824151.438250.3
1197.425156.739-
12100.026162.240-
13103.527167.941-
14107.228173.842-

SECTION 6 INSIDE VIEWS

TOP VIEW (MAIN UNIT)

The main unit contains:

BOTTOM VIEW (RX UNIT)

The RX unit contains:

SECTION 7 MAINTENANCE

OPERATING ENVIRONMENT

The IC-28A/E is a sensitive electronic device. Avoid excessively hot, humid, or dusty environments. Protect it from strong vibrations and water damage.

ADJUSTMENTS

No internal adjustments are required as all components are factory-set. Do not attempt internal adjustments, as this may damage the transceiver.

MALFUNCTIONS

Many apparent problems can be resolved by resetting the internal microcomputer (CPU). Refer to SECTION 5 - 8 for instructions. If problems persist, contact an ICOM authorized dealer.

CLEANING

Remove the front panel knobs. Clean the unit with a soft cloth and mild soapy solution. Do not use strong chemicals or solvents. Wipe dry before replacing knobs.

FUSES

The IC-28A/E uses 15 ampere fuses in the DC power cable. Identify and correct the cause of a blown fuse before replacing it.

CHANGING A FUSE

The fuse holder is located in the DC power cable. Unscrew the end cap, remove the blown fuse, insert a new 15A fuse, and screw the end cap back on.

TROUBLESHOOTING TABLE

PROBLEMPOSSIBLE CAUSESOLUTION
1. No power when VOL/PWR is ON.- Improper power cable connection.
- Poor power connector contact.
- Incorrect power polarity.
- Blown fuse.		- Reconnect power cable.
- Check connector pins.
- Verify polarity and reconnect.
- Check cause, replace fuse.
2. No sound from speaker.- Volume too low.
- SQUELCH CONTROL set incorrectly.
- External speaker connected.		- Adjust volume.
- Adjust squelch to quiet noise.
- Check external speaker connection.
3. Low sensitivity, only strong signals audible.- Antenna feedline damaged.- Check and replace feedline if necessary.
4. No or low RF output.- LOW power selected.
- PTT switch connection issue.		- Select HIGH power.
- Check MIC CONNECTOR pins.
5. No transmitter modulation.- Poor MIC CONNECTOR connection.- Check MIC CONNECTOR pins.
6. Frequency not changing with TUNING CONTROL.- MEMORY mode selected.- Select VFO mode.
7. Abnormal frequency displayed.- CPU malfunction.
- Backup battery exhausted.		- Reset CPU (SECTION 5-8).
- Contact ICOM dealer/service center.
8. Scan functions do not stop on signals.- SQL/CHK CONTROL set incorrectly.- Adjust squelch to quiet noise.
9. Memory frequencies change after CPU reset.- Memories are initialized after CPU reset.- Reprogram memory channels.

SECTION 8 BLOCK DIAGRAM

A block diagram illustrating the internal components and signal flow of the IC-28A/E is provided for technical reference.

SECTION 9 OPTIONS

Various optional units are available to enhance the functionality of the IC-28A/E:

Refer to the accompanying instruction sheets for installation and detailed operation of these optional units.

ICOM INCORPORATED
1-6-19, KAMIKURATSUKURI, HIRANO-KU, OSAKA 547, JAPAN

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