I cannot speak for his audio panel kit, however, 20-some years ago I
built one of his intercoms.
If the audio panel construction manual is anything like the intercom
construction manual, follow the directions as printed and it will work.

Tim Witt wrote:

I am not a shill for Jim Weir but am interested in his audio panel
kit. How difficult are they to put together? I'm not an EE but I do
enjoy tinkering with cars and planes. I just bought a second Nav/Com
and thought an audio panel acquisition should be in order next
(airplane currently has separate switches for radios and a portable
intercom). It would be nice to clean up all the wires hanging around
from the portable intercom and headsets, too. I'll leave the
installation up to the pros but I'd like to save some money and the
kit route for the audio panel looks like a possibility. Jim's
comments are welcome but I'd like some input from someone who has put
together a kit and doesn't solder for a living. Thanks in advance.
Tim Witt/C-150M