Note
The Kenwood TM-631A is a dual-band FM transceiver covering the 144 and 220 MHz bands.
Features
– Dual-Band Operation: Supports simultaneous monitoring or alternating between the 144 and 220 MHz bands.
– Automatic Band Change (A.B.C.): Automatically transfers the contents of the SUB band to the MAIN band when a signal strong enough to open the squelch is received.
– Memory Channels: Allows for storing and recalling frequencies.
– Multiple Scan Modes: Includes VFO scan, Memory Recall (MR) scan, programmable band scan, and "double scan".
– Priority Alert: Monitors a specific channel for activity.
– Main and Sub Tuning Controls: Separate controls for selecting frequencies on the main and sub bands.
– Balance Control: Proportions audio volume between the two bands.
– Dimmer Function: Adjusts the intensity of the LCD display and control illumination.
– Tone Operation: Includes CTCSS (Continuous Tone-Coded Squelch System) selection when the optional TSU-6 unit is installed.
– Autopatch: Available on the U.S.A. version for phone patch operations.
Specifications
_ Frequency Range: 144–148 MHz; 220–225 MHz
_ Mode: FM
_ Antenna Impedance: 50 ohms
– Operating Temp: -20°C to +60°C (-4°F to +140°F)
– RF Output Power:
HI: 144 MHz (50 W), 220 MHz (25 W)
LOW: 5 W
– Modulation: Reactance modulation
– Maximum Frequency Deviation: ±5 kHz
– Spurious Radiation: Less than -60 dB
– Audio Distortion: Less than 3% (300 to 3000 Hz at 60% modulation)
– Microphone Impedance: 500 to 600 ohms
– Receiver Circuitry: Double conversion superheterodyne
– Intermediate Frequencies:
144 MHz (16.9 MHz / 455 kHz)
220 MHz (30.825 MHz / 455 kHz)
– Sensitivity (12 dB SINAD):
144 MHz (< 0.2 µV)
220 MHz (< 0.18 µV)
– Selectivity: -6 dB (More than 12 kHz), -60 dB (Less than 24 kHz)
– Squelch Sensitivity: Less than 0.09 µV
– Audio Output: More than 2 W (8 ohms load, 5% distortion)
Power Requirements: 13.8 VDC ± 15%
Current Drain (Transmit): Less than 11 A
Current Drain (Receive): Less than 0.6 A (no signal)
