This FM advertising suppressor (SCA) decoder circuit was suggested by Signetics in a 1980s documentation. The circuitry decodes the 67 kHz signal. The integrated circuit used is of the time.
This field strength meter for the 11-meter range was found in Radio Electronics magazine from...
The output stage of this amplifier can operate at high voltage. The transistor must be a high...
This article is from an old publication from 1978. The transistor can be a BC548 and the power...