I've posted this on the Aeroelectric web site, but figured some of you
have a similar setup and might be interested in a failure mode that I
didn't think of when I setup my panel.   I have a PMA 8000b audio
panel and an SL30 as com 1 and SL40 as com 2.  I have a dual alt/dual
battery (z-14) system that are separate and can be connected with a
cross tie.  When no power is applied to the audio panel, it defaults
to com 1 and com 2 is not usable.  So if you wire both the audio panel
and com 1 on the same bus (like I did), then failure of that buss
leaves you without any ability to transmit or receive.  Com 2 is not
available.  The solution is to just hit the cross tie, but really the
better way is to wire the audio panel and com 1 on separate busses.

Dan Ballin
LEG #286