Re: Demod Woes

I don't have a specific answer but some general suggestions...

you know of course that the BW of an FM signal in considerably wider
compared to the deviation? maybe as much as 270 kHz in your
case...there is nothing in the system that restricts the BW too much?

is the distortion worse with high modulating frequencies for a given
deviation? indicates a BW issue.. plot out all the Bessel sidebands to
see this

does the distrotion suddently get worse when you exceed a certain
deviation regardless of modulating freq? may indicate overflow issue


what does the demodulated tone look like on a scope? is there any
clipping, crossover distortion? any visable error?

odd order distortion indicates you have the same error for the + and -
portions of the demodulated waveform,.... can you see if it is sudden
clipping or a gradual compression?

Mark

.

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