Mark 12D Problem???

You have not mischaracterized me... ;-)

I beleive you are probably on to something with the connection
diagnosis... Vibration would be a great explanation to the 30 minutes
of working, then failure. I thought heat might have had something to
do with it to, but sometimes it fails at first attempt of using it.

I will try your suggestion and report back... (It may be a day or two)


I will also report back on models of audio panel and intercom I have.
(The second image in the link I sent "Figure 7-11 Used with Three
Transmitters" looks exactly like my audio panel, if it helps) The
intercom doesn't have anything indicative of a model on it, so I'll
have to poke around.

Thanks again and I'll report back soon!
Todd