I'm trying (for a long time) to build an stereo generator for using with my little PLL transmitter but I CAN'T set it to work right!
After a lot of searching in the net, I still have many doubts about how the multiplexing works....Not to mention the wrong diagrams out there..
Actually, is the third multiplexer that I have build so far, but the sin wave that I put into one channel of the multiplexer keep playing together among the 2 speakers...(yes, the pilot light on receiver is ON)
What I know(and what I actually see in the scope):
-Chopping channels at 38 kHz
-join them with a ~10% overral amplitude 19kHz tune
-filter the signals (~60kHz LPF)
What I don't know
-I need a phase shift between the pilot and the chopping? Or the shift has to be exatcly 0Âº?
-The wrong overral level would cause incorrect channel separation?
-Any critical advice to me?
Well, any help in places/books to find information is appreciated...I am almost giving up with this, cus I don't really see why the channel separation is almost zero even at a decoder that I built(with LM1800N)
Thank You guys!