Kenwood TR-7400A

The Kenwood TR-7400A is a digitally synthesized high performance, 2 meter mobile FM transceiver. It features a full frequency digital LED display. Transmit power may be set for 5 or 25 watts. Frequency range is 144 - 147.995 MHz. 7.3 x 2.875 x 10.6 inches 6.2 lbs. Requires 13.8 VDC at 8 amps. Comes with hand mic (4 pin), mobile mounting bracket and DC cord.

Trio-Kenwood Electronic Inc.; Komagane; Introduced in 1977

Features (described in 1977)

The most complete squelch system yet devised:

The TR-7400A has provisions for continuous tone-coded squelch (CTCS); encode and decode or encode only. Common frequency active filters are available (optional). Also, tone burst operation can be achieved by inserting optional tone burst modules(TBM).Standard frequency modules are available at your KENWOOD dealer. Of course, the TR-7400A can be used for normal carrier squelch operation. A convenient, front panel switch selects the squelch system you desire. This versatile, self-contained squelch system allows the TR-7400A user to "access" any of his favorite repeaters.

High Power, Solid State Final:

The KENWOOD TR-7400A is conservatively rated at 25 Watts RF output power to provide solid, reliable communications. High performance and reliability are obtained through the use of the Motorola MRF-208 (driver) and 2N6083 (final) transistors mounted on a large die cast heat sink. Digital Frequency Display: Large light-emitting diodes (LEDs) indicate your operating frequency in six digits allowing fast, efficient readout.

800 Channel Coverage:

The phase-locked loop (PLL) frequency synthesizer in the TR-7400A divides the 4 MHz bandwidth into 400 channels at intervals of 10 kHz. The frequency may be offset 5 kHz higher with the push of a button, thus providing 800 discrete channels.

Final Protection Circuit:

The final transistor in the TR-7400A is protected from antenna impedance mismatch. Excessive reflected power reduces the amount of drive to the final transistor rather than turning off the final stage. This practical feature allows continued safe operation at a reduced power level whether the antenna becomes opened or shorted.

Excellent Output Signal:

Effectively minimizes unwanted output signals. Second and third harmonics are down better than -60 dB. PLL Unlock Protection Circuit: In the event that the TR-7400A's PLL synthesizer circuit becomes unlocked, a built-in protection circuit prevents the unit from radiating all unwanted signals. This condition is indicated by a front panel LED.

Repeater Offset Circuit:

A convenient front panel switch offsets the transmit frequency of the TR-7400A up OR down 600 kHz for standard repeater operation. This offset circuit uses digital technology to provide a highly stable offset frequency without spurious response.

Low Power Position:

The TR-7400A is also capable of low power (5 Watts) operation at the push of a button for use with most 2-meter FM amplifiers. Superior Receiver Characteristics: The large helical resonators, 2-pole 10.7 MHz monolithic crystal filter, and MOSFET front-end circuitry combine to give outstanding performance.

Details: Requires addon tone board for PL repeater use, band pass front end on RX, no wideband, and no out of band mods.