Rca Inc.

Paul L Buess

Bortolo M Pradal

Robert M Kongelka

A switched microphone hang-up bracket includes an outer case for receiving a microphone which is releasably secured thereto. The microphone is of the type which may be used in a mobile two-way radio system having a continuous tone coded squelch system (CTCSS) disable switch. The bracket includes a camming device for mechanically placing the switch in either the enable or disable mode to selectively place the receiver in a 'noise squelch' and 'channel monitoring' mode or in the off position, as desired, while the microphone is in place in its bracket.

Switched microphone hang-up bracket

A direct FM modulator includes an oscillator comprising a current conducting device providing amplification to sustain oscillations and a frequency determining circuit connected thereto for controlling the frequency of oscillation. The frequency determining circuit includes a piezoelectric element in series with a voltage variable capacitance and an adjustable capacitance coupled across this series combination. The capacitance of the voltage variable capacitance is changed by a modulating voltage to provide frequency deviation about the center frequency of oscillation. A frequency linearization of the crystal oscillator is provided by a selected value of capacitance coupled across the varactor and the capacitance value of the adjustable capacitance such that the frequency deviation vs. voltage is maximum at the initial reference bias voltage and is symmetrical about this reference bias.

Growing community of inventors

Pittsburgh, PA, United States of America

Paul L Buess