The presented circuit makes use of a common operational amplifier that must be powered by a symmetrical source. R resistors from 10k to 1M determine the gain and compression of the signal.
This is the receiver circuit for the previous remote control published in the same Radio...
This circuit, for signals up to 1 MHz, is based on an RCA operational amplifier. The circuit was...
This frequency shift modulation circuit was found in the November 1994 issue of Electronics Now...