I installed a microair comm last week in my Cirrus. I to am getting
static that sounds like morse code. Like you I noticed that when the
EW microrecorder is turned off the static goes away. Evidently the
GPS receiver emits electrical impulses that are received by the comm
radio. I believe I can adjust my squelch so that it is not too
annoying. I don't believe the speaker wire is the culprit.