The Telex Radio Dispatch DSP-223 Tone-remote adapter provides a reliable means of remotely controlling two-way radio base stations. The adapter can be used in conjunction with all Radio Dispatch consoles, or other manufacturers’ (such as Motorola and GE) remote consoles that use the industry-standard sequential tone-keying format. The DSP-223 is interconnected to the distant remote control console(s) by any voice-grade transmission medium such as a microwave link, a leased telephone line, or a twisted-pair 600-ohm line. All DSP- 223s are capable of decoding the PTT (push-to-talk/transmitter-on) tone sequence and the voice-plus-tone signals during transmission. All models are prepared for jumper-plug conversion from two-wire-line operation to four-wire-line operation. In the four-wire mode, the panels are full-duplex capable.