I'm working on a stereo FM modulator/demodulator, buth channels get mixed, so I'm doing some test and I have found taht this diagram (faulty.grc.png) does not work well. The output of the adder seems fine
Pilot at 19Khz, lower part of the spectrum with tones at 1Khz and 12Khz, and upper part with tones at 38K+-1K and 38K+-12K (as is a power spectrum signs are not show)
But signals R and L show both 1K + 12K tones insted of just 1K tone in one of then and one 12K tone in the other.
I have been testing part of the diagram apart one of the other and I have found that if I only do the add+substract part It work well
And if I only do the add+frequency displacement It work well too .... so I'm puzzled.
Any ideas please?
regards
