Tuesday, May 25, 2010

pll spurious

The pll produces a signal between 133.3 and 135.3 MHz.This signal had some spurious 2MHz away from the carrier. I found out that it was caused by a 132.3 MHz signal. This signal leaked to the vco via the power lines.

I fixed this. Now I don't see any spurious around the carrier.So it is attenuated at least 60 db.

132.3 MHz is used to downmix the vco signal from 133.3-135.3 to 1-3 MHz.

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