I think I've found the problem.

All the chattering seems to emanate from on of the two JR 549 FM receivers in the plane. Swapping it out for an older one consistently stopped the chattering.

NOW the problem is, I've got about eleven of these receivers, and I found similar behavior in one that I put in my yet-to-fly Yellow P-38. That makes two of eleven malfunctioning receivers, none of them crashed, all of them well-padded, one of the failures not even flown yet!

Anybody hear of problems like that? I'm about ready to switch back to Futaba. That's gonna leave a dent in the wallet!

mt