Motorola Corporation

Walter Louis Berenson

Ronald Wayne Taylor

Morton Stern

Wayne J Bates

William H Euchner, Jr

James H Grigg

A mixer connected to receive a pilot signal from a suppressed carrier communications system and further connected to receive a signal from a crystal controlled oscillator with a plug-in crystal is disclosed. The output of the mixer is coupled through a very narrow bandpass filter tuned to pass only the converted pilot frequency. The output of the mixer develops a control signal which is coupled to a regulating input of variable gain amplifier means for regulating the gain of the amplifier means in direct proportion to changes in level of the pilot.

Omni-frequency pilot system

A modem having a transmitter portion including a first modulator connected to receive audio frequency signals and supplying an output signal through a single sideband filter to a second modulator providing an output signal at a unique channel frequency, a receiver portion including a first demodulator connected to receive transmitted signals and supplying an output signal to a second demodulator through a single sideband filter with the second demodulator providing audio frequency output signals, a carrier switch supplying a small amount of the carrier to the second modulator during operation of the transmitter and a carrier level switch associated with the carrier switch for supplying the carrier at high and low levels, and a crystal controlled channel oscillator connected to the second modulator of the transmitter portion and the first demodulator of the receiver portion with removable, plugin crystals connected thereto for controlling the channel frequency of the modem.

Growing community of inventors

Palatine, IL, United States of America

Walter Louis Berenson