Telephone patch

Abstract

Electronic patch circuitry interconnects a wire telephone line with the base station transmitter and receiver of a simplex two-way radio communication system, for causing VOX-type operation with very fast voice-operated keying between transmitter and receiver. The system is operable in a telephone line priority mode in which it responds to telephone line audio signals for keying the transmitter on and the receiver off regardless of whether or not the receiver is on at the time, and is also operable in an 'anti-VOX' mode. An automatic telephone line connector circuit responds to telephone ringing signals on the telephone line at the base station. The circuit then transmits a coded signal to a remote radio transceiver, which can return a signal to 'answer' the base station telephone and connect it to the patch circuitry. Automatic dialing means are provided for initiating a telephone call from the remote radio transceiver. Timing circuitry holds the base transmitter off for a short time immediately after each telephone line connection to insure monitoring of the radio channel by the telephone subscriber before he can transmit. Additional transmit-on timers key the base transmitter off if it is on too long. The system 'hangs up' the base station telephone after predetermined timed events or when dial tone occurs to prevent tie-up of the interconnection by the telephone line party.