Abstract: A radio includes a receiver circuit, a microprocessor, an input/output (I/O) port, at least one switch for configuring the I/O port, an audio amplifier coupled to the receiver circuit and to the I/O port, an audio frequency transducer coupled to the I/O port, and a power supply coupled to the I/O port, the receiver, the microprocessor, the at least one switch, and the audio amplifier. The at least one switch is coupled to the microprocessor. The audio frequency transducer is selectively coupled to the audio amplifier through the I/O port and the power supply is selectively coupled to the I/O port to permit activation of the audio frequency transducer by a signal coupled from the audio amplifier through the I/O port and to provide access to the power supply through the I/O port.

Abstract: A portable transceiver includes a two-piece transceiver housing which encloses a double-sided printed circuit board. The transceiver housing includes a front surface portion and a control panel portion which is integral with, but recessed below, the front surface portion. Within the control panel portion are four clearance apertures which provide operator access to the operator controls of the printed circuit board. The width and depth of the housing are suitably sized to enable the portable transceiver to be hand held in one hand while the thumb of that same hand is able to manipulate the various operator controls. These controls protrude through the various clearance apertures yet the outermost portions of the controls remain flush with to recessed below the front surface portion. The printed circuit board is a self-contained transceiver such that all wiring is completed prior to installing the printed circuit board into the transceiver housing.

Abstract: A network for connecting a receiver and a transmitter to a common antenna to utilize the antenna for both transmit and receive modes of operation is disclosed, which network is suitable for either relay antenna switching or solid state antenna switching. The network includes a band pass filter coupling the transmitter output to the antenna at least during the transmit mode of operation and first and second filter junction points for coupling the antenna to the receiver. One of the first and second junction points is coupled to the receiver at least during the receive mode of operation, and includes means for inhibiting the application of the transmitter output signal to the receiver during the transmit mode of operation.