Kenwood TM-255a Plus TM-455a All Mode Transceiver Combo Owner Manual Schmatics etc
Ham Radio All-Mode Transeiver Pair: Rare Kenwood TM-255A and TM-455A Radios. These are a matched pair, used for Sat and Moon Bounce work but have features needed for normal repeater and simplex on AM FM CW and SSB. These little guys do it all. Read the specs below for details. Sold only together. Have had very little use, been setting in the ham shack without being used because I never had the necessary antennas. Used a little on sideband, much better way to talk. In perfect condition, includes original mics, mobile mounting brackets, owners manuals with schmatics and some added power cords designed for use in a mobile setup if preferred. Pictures are of actual radios. Sell on ebay for upwards of $700 for the pair but I'd rather not deal with ebay. Call if you have questions. Thanks...Bob Weaver Asking price $450 plus shipping probably around $30. That price is for both radios, about $225 for an all-mode Kenwood.
All-Mode Transceiver TM-255/455(A/E)
All-mode versatility enters a new era with our innovative TM-255A/E (2 m) and TM-455A/E (70 cm), both featuring a detachable front panel for easy mounting in a car. But whether mobile or stationary, these compact transceivers offer matchless performance -- in FM, SSB and CW modes. Among their many impressive features are 101 memory channels, DDS with "fuzzy logic" control, twin tuning dials, and a data connector for 1200/9600 bps packet communications.
Features at a glance:
2 m (TM-255A/E) or 70 cm (TM-455A/E) all-mode operation
101 memory channels
DDS with "fuzzy logic" control
TF-SET (TX frequency set) function
DTSS selective calling with pager function
1200/9600 bps packet terminal
TM-255/455(A/E) in detail:
Maximum RF output is 40 watts (TM-255A/E), and 35 watts (TM-455A/E). A HI/LO switch enables power reduction to 5 watts.
100 multi-function memory channels plus 1 call channel
Facilitating on-the-move operation are 101 memory channels, plus memory shift and memory scroll functions. Channels 50~98 are capable of storing transmit and receive frequencies independently.
There is a choice of full band and programme band scans, memory scan with memory channel lock-out, MHz scan and V/M/C scan. The operator can also select time-operated or carrier-operated scan stop modes, and adjust scan speed.
Data connector for 1200/9600 bps packet
A 6-pin mini DIN connector lets the operator enjoy either standard 1200 bps or 9600 bps high-speed packet communications with a TNC.
DDS (Direct Digital Synthesizer) with fuzzy control
We've incorporated "fuzzy logic" control circuitry, so the main encoder tunes smoothly from fine (5 Hz step) to fast forward (200 Hz step).
Twin tuning dials
In addition to the smooth-action dial on the main unit, there is a click-type dial on the detachable panel for convenient mobile use.
The user-friendly menus -- which are also accessible via the supplied microphone -- are divided into two groups (A & B) depending on frequency of use.
AIP (Advanced Intercept Point) circuitry allows the operator to choose either high sensitivity or a high intercept point to suit conditions. IF-SHIFT (SSB, CW) and a pulse noise blanker further improve RX performance.
TF-SET is available when the receive frequency is locked, so the operator can avoid losing a targeted station.
The supplied remote-control microphone has 4 programmable function keys -- ideal for mobile operation.
Built-in DTSS selective calling with pager
Semi break-in circuit (CW)
Automatic mic gain control circuit (SSB)
Built-in TCXO (temperature-compensated crystal oscillator)
Tone alert system with elapsed time indicator
Built-in CTCSS encoder & optional decoder (TSU-8)
Auto power-off & time-out timer
Dimensions (W x H x D) 180 x 60 x 215.5 mm (7.0 x 2.4 x 8.5 in.
NOTE: The mic connectors I use allow you to disconnect the mic without having to remove the faceplate. When used in data mode for sat or moon work, the mics are not needed and are best removed so you don't accidently key the radio. You can remove the faceplate, remove the mic cable and replace it with the mic itself and you will be back to stock. No modifications were made to the radios, just the added pigtail to the mic.
Robert D. Weaver K7RDW
Robert D. Weaver K7RDW