The Technisonic TAF-550 VHF/AM/FM modular communications system is a transportable AM and FM base station capable of operating simultaneously on any 25 KHz VHF/AM aeronautical band frequency (117.975 to 138.000 MHz) as well as any VHF/FM high band (138.000 MHz to 174.000 MHz) frequency. Power for the TAF-550 can be external 120VAC, external 12VDC or 24VDC. Both transceiver modules utilize state of the art, microprocessor controlled frequency synthesis techniques to provide communications on every currently available channel. The TAF-550 AM/FM modular system is mounted into a rugged transportable case with protective covers (front and rear) into which the accessories (microphone, power cables, antenna cable, etc.) can be stored. It is intended for temporary, emergency or backup operation in a fixed environment.

The FM transceiver incorporated into the TAF-550 is the Technisonic TFM-138B which can be operated in the direct entry or simplex mode by simply keying in the desired operating frequency, or can function without restriction on any split frequency pair within the band. It features 120 preset memory positions each of which is capable of storing a receive frequency, a transmit frequency, a separate CTCSS tone for each receive and transmit frequency and an alpha-numeric identifier for each channel. The TFM-138B also offers the capability of allowing for DPL or DCS coded squelch operation. This transceiver allows either 25 KHz wide band or 12.5 KHz narrow band operation on any or all of 120 preset channels. Data can be easily entered into any of the preset non-volatile memory positions for both main and guard channels via the front panel keyboard. Information stored in memory is available for instant recall by keypad entry, or by pressing the "Up" or "Down" button which allows the operator to scroll through all preset channels. Technisonic FM transceivers feature a synthsized two channel guard, receiver, a DTMF encoder for signaling during transmit, and a scan function which will scan any or all of the frequencies stored in the preset memory positions.

The VHF/AM transceiver incorporated into the TAF-550 is the Technisonic high performance 91-DE. This transceiver allows the operator to store up to 10 channels in non-volatile memory which are displayed on a front panel LCD, and then easily recall, seek or scan them. Receive only channels to prevent unauthorized transmission as well as a 90 second time out feature are easily programmed via the front panel 12 button key pad. The highly sensitive and selective receiver provides for superior long distance communication. A 35 dB Rx and Tx audio compressor maintains constant audio level and modulation. A user adjustable squelch and external headset jack are conveniently located on the front panel. A noise cancelling dynamic microphone (included) provides for clear audio even in a high noise environment.