Looked into this a bit more.?Scope is telling me that there is a?carrier (when trimmed to a minimum) of?1V peak to peak. This is after it settles down from the initial transient spike?which appears to be 60V peak to peak.? All into a dummy load.??Audio from a nearby receiver suggests?that it is the carrier tone that is the spike signal.
Tried unplugging the speaker, the mic, the volume control, no difference.
