kenwood tm 281a manual pdf

The Kenwood TM-281A is a 65W VHF FM transceiver designed for mobile operation in the 144-148MHz amateur band. This robust radio features a large LCD display, simple operation, weather alert function, 200 memory channels, DTMF memory, and wide frequency coverage. Below are key sections covering features, installation, operation, programming, and troubleshooting.

Features at a Glance

Key components: Main unit, microphone, mounting bracket, DC power cable, and user manual.

Installation

Unpack and inspect all components before installation.

1. Mounting: Use provided bracket to securely mount in vehicle.
2. Power Connection: Connect red wire to positive (+), black wire to negative (-) of 13.8V DC source.
3. Antenna Connection: Connect suitable VHF antenna to ANT connector.
4. Microphone Connection: Plug microphone into MIC connector.
5. Grounding: Ensure proper grounding for optimal performance.

WARNING! Ensure proper fuse rating (15A recommended). Do not operate without proper antenna connected.

Basic Operation

Power on the unit and familiarize yourself with basic functions.

1. Power On/Off: Rotate VOLUME control to turn on.
2. Volume Control: Rotate outer knob to adjust audio level.
3. Squelch Control: Rotate inner knob to set squelch threshold.
4. Frequency Selection: Use keypad or tuning knob to set frequency.
5. Power Selection: Press [LOW] to toggle between 65W/25W/5W.
6. Channel Selection: Press [V/M] to switch between VFO and memory modes.

CAUTION! Always verify frequency and power settings before transmitting.

Specifications

• Frequency Range: 144-148 MHz (RX), 144-148 MHz (TX)
• Mode: FM
• Output Power: 65W/25W/5W selectable
• Input Power: 13.8V DC ±15%
• Current Drain: 12A max (at 65W), 0.5A (standby)
• Impedance: 50 ohms
• Dimensions: 140(W) x 40(H) x 159(D) mm
• Weight: 1.1 kg
• Temperature Range: -20°C to +60°C
• Memory Channels: 200 channels

Controls and Functions

Front Panel: VOLUME/SQUELCH knobs, POWER/LOW button, [F] function key, [V/M] key, [CALL] key, numeric keypad.

Microphone: PTT, UP/DOWN keys, [F] key, numeric keypad.

Basic Functions: [F] + POWER = Display backlight, [F] + LOW = Power level selection, [F] + 1 = Tone encoder, [F] + 2 = Reverse function, [F] + 3 = Offset direction, [F] + 4 = Tone squelch. Advanced Functions: [F] + 7 = Memory channel mode, [F] + 8 = Scan mode selection, [F] + 9 = Weather alert setup.

Memory Programming

Store frequently used frequencies and settings in memory channels.

1. Select desired frequency and settings in VFO mode.
2. Press [F] then [7] to enter memory mode.
3. Use UP/DOWN keys or keypad to select memory channel.
4. Press [F] again to store settings.
5. Press [V/M] to switch between VFO and memory modes.

Tip: Memory channels can store frequency, offset, tone settings, and power level.

DTMF Operation

The TM-281A features DTMF encoding for repeater access and remote control.

1. DTMF Memory: Store up to 16 DTMF sequences in memory.
2. Manual Entry: Use microphone keypad to send DTMF tones directly.
3. Memory Recall: Press [F] + [*] to access DTMF memory mode.
4. Auto Dial: Program frequently used numbers for quick access.
5. DTMF Speed: Adjust transmission speed in function menu.

WARNING! Ensure proper DTMF settings before attempting repeater access.

Weather Alert Function

Monitor NOAA weather channels and receive emergency alerts.

1. Weather Channel: Press [WX] to access weather channels.
2. Weather Scan: Press [F] + [WX] to scan all weather channels.
3. Alert Function: Enable weather alert to receive emergency broadcasts.
4. Alert Tone: Adjust alert volume and tone in settings.

Maintenance & Care

Keep the unit clean and protected from extreme conditions.

Cleaning: Use soft, dry cloth. Do not use chemicals or solvents.

Storage: Store in dry, temperature-controlled environment.

Antenna: Regularly inspect antenna and connections for damage.

CAUTION! Do not expose to moisture, extreme temperatures, or direct sunlight for extended periods.

Regulatory Information

FCC Part 97: This device complies with Part 97 of the FCC rules for amateur radio service. Operation requires valid amateur radio license. Kenwood Corporation. For technical support, contact authorized Kenwood service centers or visit www.kenwood.com.

Troubleshooting

Reset: Turn off unit, press [F] + POWER while turning on to reset to factory defaults.

Service: Contact authorized Kenwood service center for repairs.