Omni-frequency pilot system

摘要

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.