Kenwood TM 731A Manual

The Kenwood TM 731A is a dual-band amateur radio transceiver featuring 2-meter (144-148 MHz) and 70-cm (430-450 MHz) operation with cross-band repeat function, 50 memory channels, CTCSS/DCS encode and decode, wide frequency coverage, and multiple scanning modes. Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

Features at a Glance

Key components: Dual-band transceiver, microphone connector, DC power input, antenna connectors, external speaker jack, data port.

Feature	Description
Dual-band operation	144-148 MHz (2m) and 430-450 MHz (70cm)
Cross-band repeat	Allows communication between two bands
Memory channels	50 memory channels with alphanumeric tags
CTCSS/DCS	Tone encode and decode functions
Scanning modes	Programmable scan, memory scan, band scan
Power output	High/Low power settings (50W/5W on 2m, 35W/5W on 70cm)
DC power input	13.8V DC negative ground
Antenna connectors	SO-239 for 2m, N-type for 70cm
External speaker jack	For external audio output
Data port	For packet radio and external control

Installation

Unpack and inspect contents. Choose suitable mounting location.

1. Connect power: Use proper gauge wire; connect red to positive, black to negative (13.8V DC).
2. Install antennas: Connect 2m antenna to SO-239 connector; 70cm antenna to N-type connector.
3. Connect microphone: Plug microphone into front panel connector.
4. Mount securely: Use mounting bracket for mobile installation.

WARNING! Ensure proper polarity when connecting power to avoid damage. Use appropriate fuses.

First-Time Setup

Power on radio; initialize settings.

1. Set operating frequency: Use main dial to select desired frequency on either band.
2. Configure CTCSS/DCS: Access TONE menu to set encode/decode tones as needed.
3. Program memory channels: Store frequently used frequencies with alphanumeric tags.
4. Adjust squelch: Set squelch level to eliminate background noise.
5. Configure cross-band repeat: Enable in FUNCTION menu if required.

CAUTION! Ensure proper antenna installation before transmitting.

Specifications

• Frequency Range: 144-148 MHz (2m), 430-450 MHz (70cm)
• Power Output: 50W/5W (2m), 35W/5W (70cm)
• Modulation: FM
• Memory Channels: 50 channels with alphanumeric tags
• CTCSS Tones: 38 standard tones
• DCS Codes: 104 digital codes
• Power Supply: 13.8V DC ±15% negative ground
• Current Drain: Receive: 0.8A, Transmit: 10A (max)
• Dimensions: 140(W) × 45(H) × 180(D) mm
• Weight: 1.2 kg

Controls and Settings

Front Panel: POWER, VOLUME, SQUELCH, main tuning dial, function keys, microphone connector.

Microphone: PTT, UP/DOWN keys, function buttons, numeric keypad.

Menu Functions: TONE (CTCSS/DCS settings), SCAN (scan configuration), MEMORY (channel programming), SET (general settings), REPEAT (cross-band setup). Audio: Volume, squelch, tone control. Display: Backlight brightness, contrast adjustment.

Connecting Accessories

External speaker: Use 3.5mm jack. Data: Use data port for packet radio. Power: 13.8V DC input.

1. Turn off radio before connecting accessories.
2. Match connectors properly (audio jack, data port).
3. Ensure proper cable routing to avoid interference.

Tip: Use shielded cables for data connections to reduce noise.

Operating Modes

Supports simplex, repeater operation, cross-band repeat.

1. Simplex operation: Direct communication on same frequency.
2. Repeater operation: Set offset and CTCSS tones for repeater access.
3. Cross-band repeat: Enable in FUNCTION menu to relay between bands.
4. Scanning: Programmable scan, memory scan, band scan modes.
5. Dual watch: Monitor two frequencies simultaneously.
6. Priority watch: Monitor priority channel while operating.

WARNING! Ensure you have proper license for operating frequencies.

Memory Functions

Store frequencies, offsets, and tones in 50 memory channels.

1. Store memory: Tune to frequency, press [F] then [MR] to store.
2. Recall memory: Press [MR] and select channel with dial or keypad.
3. Memory name: Assign alphanumeric names to channels.
4. Memory scan: Scan through programmed memory channels.
5. Memory lock: Lock important channels to prevent accidental changes.

Care & Maintenance

Keep radio clean and dry. Use soft cloth for cleaning; avoid chemicals.

CAUTION! Do not use solvents or abrasive cleaners. Keep away from moisture and extreme temperatures.

Regulatory Information

FCC Part 97: Certified for amateur radio service. This device complies with Part 15 of FCC rules. Copyright © Kenwood Corporation. For technical support, contact authorized Kenwood service centers or visit www.kenwood.com.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No power	Power connection/fuse	Check power connections; verify fuse; ensure proper voltage.
No transmission	PTT/microphone	Check microphone connection; verify PTT operation; check antenna.
Poor reception	Antenna/squelch	Verify antenna connections; adjust squelch; check for interference.
Memory lost	Power interruption	Re-program memory channels; check backup battery if equipped.
Cross-band not working	Settings/configuration	Verify cross-band settings; check frequency pairs; ensure proper enable.

Reset: Hold [F] + Power on to reset to factory defaults.

Service: Contact authorized Kenwood service center for repairs.