Abstract: An improved automatic switching system for switching between two sources of audio signals in a combination transceiver set and radio or tape recorder set. A transistor in the squelch control circuit of the transceiver set switches the audio signals from either the transceiver set or from the radio or tape recorder set through respective switching diodes to an output amplifier circuit, thereby reducing the complexity and cost of the system.

Abstract: Disclosed is an automatic control system for condition-responsively switching over audio signals from transceiver, radio or tape recorder. It is characterized in that a transceiver squelch control circuit having a transistor is connected through its collector electrode to a radio or tape recorder audio signal switching transistor at the base electrode thereof, thereby voltage variation in the squelch control circuit is transmitted to the radio or tape recorder audio signal switching transistor which in turn functions to switch off the radio or tape recorder audio signal.