pira.cz stereo encoder

[radium98]

  hi i am going to make the stereo encoder and here is some pictures of the project thanks to Jan.Having 1 question i did not find the U7 - PIC18F1220-I/P  i tried to use PIC18F1320-I/P as it seems must work under the data sheet and its a bit pricy does it work or no ?
thanks

[radium98]

Still cant burn the hex into the pic i think the 2 pics are fakes one be aware.

[max-bit]

Hi
I built a stereo encoder based on this project
https://pira.cz/eng/stk2en.htm
However, I have a problem with channel separation, it doesn't want to be better than the 35dB channel separation. This is not a problem of the receiver as it has a separation of ~ 43 dB (measured on a professional generator). What could be the problem?

I am attaching the eagle drawing.

thanks in advance for your comments and help

[brashtrue]

The photo you provided isn't particularly valuable. Let's get a little more specific.

[quixotichare]

I also have a problem with demultiplexing, it doesn't want to be better than 35dB demultiplexing. I don't know how to solve it?

[Rafael Reali]

If you are testing the circuit on a PLL transmitter, it needs to have good damping (or delay) on the correction signal, otherwise it will combat the pilot signal from the stereo generator.

  I suggest testing the stereo circuit on a free oscillator.