Background music decoder

Share this post!

Vote this!

This is a background music (SCA) decoder circuit from the input demodulated (multiplex) FM signal.
We use NE565 (Phase Locked Loop IC) to be base of this circuit, for easy and cheap.
A resistive voltage divider is used to set a bias for the input (pins 2 and 3).
The input passes through a two-stage high-pass filter, both to effect capacitive coupling and to attenuate the strong signal of the regular channel.    more...