Kenwood TR 7400A Manual

The Kenwood TR 7400A is a 2-meter amateur radio transceiver featuring 25W output power, 50 memory channels, built-in CTCSS encode/decode, wide/narrow bandwidth selection, programmable scanning functions, dual VFOs, and comprehensive tone and signaling capabilities. Below are key sections for operation, programming, specifications, and troubleshooting.

Features at a Glance

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

Installation

Unpack and inspect all components. Choose suitable mounting location.

1. Connect power: Red wire to positive (+), black wire to negative (-) of 13.8V DC power source.
2. Connect antenna: Use coaxial cable with PL-259 connector to SO-239 antenna jack.
3. Connect microphone: Plug 8-pin DIN connector into microphone jack.
4. Secure mounting: Use provided bracket to mount transceiver securely.

WARNING! Ensure proper polarity when connecting power. Reverse polarity may damage the unit.

Basic Operation

Power on transceiver; adjust volume and squelch controls.

1. Select frequency: Use VFO knob or keypad to enter desired frequency.
2. Set power level: Press PWR button to toggle between high (25W) and low (5W) power.
3. Adjust volume: Turn VOL knob clockwise to increase audio level.
4. Set squelch: Turn SQL knob until background noise is silenced.
5. Transmit: Press and hold microphone PTT button to transmit.

CAUTION! Ensure you have proper amateur radio license before transmitting.

Specifications

• Frequency Range: 144-148 MHz
• Output Power: 25W (high), 5W (low)
• Input Power: 13.8V DC ±15%
• Current Drain: 7A max (transmit), 0.5A (receive)
• Modulation: 16K0F3E (wide), 8K0F3E (narrow)
• Sensitivity: Better than 0.16μV for 12dB SINAD
• Selectivity: Wide: 25kHz, Narrow: 12.5kHz
• Memory Channels: 50 (including call channel)
• Antenna Impedance: 50 ohms
• Operating Temperature: -10°C to +60°C

Controls and Settings

Front Panel: POWER/VOL, SQL, VFO knob, PWR button, MHz button, Function buttons.

Microphone: PTT, Up/Down buttons, programmable function buttons.

Function Settings: Bandwidth selection, tone encode/decode, reverse function, offset direction, step size, scan modes, memory operations, display contrast, battery saver.

Memory Programming

Store frequencies and settings in 50 memory channels.

1. Select desired frequency and settings.
2. Press M.IN button to enter memory programming mode.
3. Select memory channel number using VFO knob or keypad.
4. Press M.IN again to store settings.
5. Include CTCSS tones, offset, and bandwidth as needed.

Tip: Use memory channels for frequently used repeaters and simplex frequencies.

Scanning Functions

Programmable memory scan and band scan capabilities.

1. Memory Scan: Press SCAN to scan programmed memory channels.
2. Band Scan: Hold SCAN for 2 seconds to scan entire 2-meter band.
3. Programmable Scan: Set scan limits and skip channels in menu.
4. Priority Watch: Monitor priority channel while scanning.
5. Resume Options: Time, carrier, or manual scan resume.

WARNING! Be aware of local regulations regarding scanning frequencies.

CTCSS Operation

Continuous Tone-Coded Squelch System encode and decode functions.

Encode: Transmit CTCSS tone to access tone-controlled repeaters. Decode: Receive only stations transmitting specified CTCSS tone.

Care & Maintenance

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

CAUTION! Do not expose to extreme temperatures or moisture. Ensure proper ventilation during operation.

Regulatory Information

FCC Part 97: Certified for amateur radio service. This device complies with part 15 of the FCC Rules. Operation is subject to the condition that this device does not cause harmful interference. Copyright © Kenwood Corporation. For technical support, contact authorized Kenwood service centers.

Troubleshooting

Reset: Hold FUNC and PWR while turning on for factory reset.

Service: Contact authorized Kenwood service center for repairs.