In article ,
"Michael Ware" wrote:
... but since the tip terminal wasn't connected, it was missing the
heat-shrink.
JKG

So how does the co-pilot transmit?


Only the barrel and ring of the intercom mic jack are live. Ring
connects to the intercom, and barrel to ground. Tip is not connected.
Note that this is different than the aircraft mic jack, where tip is
used to key the mic for transmit.



JKG