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 stage was found in a 1964 Electronic Design. The transistors are of the time and the shape of...
This circuit with the known PLL 567 can be found in other versions in this section and in this...
In this circuit, the LED Will blink in a presence of na áudio signal in the input. Gain is...