The TW-47 is a stand-alone interface designed to connect a 2-way radio or walkie-talkie into a single channel of a standard Clear-Com, RTS*, or compatible 2-wire party-line intercom system. It provides both audio connection and “push-to-talk” transmitter keying, using standard Call signals.

The ability of a 1- to 5- watt walkie-talkie to both talk to and receive from the wired intercom system can greatly extend an intercom system’s capability, especially in very large indoor and outdoor facilities and venues. The TW-47 is powered directly from the intercom line, and connection to the radio is via a single DB-9F 9-pin connector. The interface has extensive RF and EMI isolation to prevent the 2-way radio RF from radiating into the intercom system.

In order to accommodate the widest variety of 2-way radios, the TW-47 is supplied with a 9-pin connector and wiring diagrams for many 2-way radios.The combination of internal jumpers (switches) and front panel “Transmit” and “Receive” level controls assures correct level matching to virtually any radio. Adjustments from -57 dB microphone level to +11 dB line level are supported. A bi-color LED provides a visual indication of audio level from the intercom line.

A relay contact provides the required “Push-to-Talk” transmitter “keying”of the radio. This relay is activated by detecting the “Call Signal” on the intercom channel. The relay contacts, in conjunction with the custom-made radio cable, allow correct transmitter keying of virtually any type of radio. A “Transmit Key” LED indicates that the relay is active. Certain Clear-Com stations can be set up so that the Call signal is activated automatically when the Talk button is pressed (Talk-on-Call). With these stations, the radio transmitter can be keyed by simply pushing the Talk button. The operation of the 2-way radio then becomes seamless and transparent to station users.