comm wiring question

Hope not to get longwinded about this but the simple answer is NO. It is a little bit more complex but not very.

The main issue is that of isolation between Com-1 and Com-2. You have already recognized that you'll need a switch to switch the mike keying between both radios. What you may not be aware of is that on GA radio equipment, using dynamic microphones with GA impedances (different from military) the radio priovides 9 volts DC bias to operate the microphones. Connecting both radios with their respective bias supplies is not a good idea. At the very least, if there is a failure of one com you may lose both by tying common items together. The same thing holds true for the headphone or audio outputs. They should NOT be tied together in parallel without some way of isolating them from each other.

Almost all dual radio installations, going back to the 1960's had some sort of a switching panel and later electronic audio panels to perform these functions.

Hope this helps, ring me up if you have any other questions.

Planeflyr