Fluctuating CHTs

[cmarbach]

What could cause all the CHTs and EGTs fluctuate rhythmically and be affected by how many amps the alternator is drawing?

I have a .mov file of this which I can email if it would help.

 

[Dynon]

Generically / vaguely, a grounding issue somewhere. Here's an earlier discussion on this that may help: http://dynonavionics.com/cgi-bin/yabb2/YaBB.pl?num=1173537125