Hello. I am using a colpitt crystal oscillator of about 25Mhz. I want to use that as my base frequency and then have another circuit that can output multiple copies with slightly different frequencies like 26Mhz, 27Mhz etc. I have the book by Horowitz and I noticed something similar. It is a quadrature oscillator circuit. However, what I was able to gather is it only produces a 90 degree phase shifted copy of the signal that was used as the input. My question is suppose I modulate both of these signals with an audio wave, then how can a radio receiving operating at medium wave be able to distinguish between the two because both signals have the same frequency but are only out of phase. The answer might be obvious but I'd like to be sure. Second, how can I possibly create copies of the original colpitt output signal with slight frequency differences. I hope I can get an answer.