RST Engineering wrote:

Nobody ever said anything about "talking" on different frequencies. There
are a few dozen spurious responses on the best designed receiver that will
take your ears off when the other person transmits on the other transceiver.
It takes one hell of a lot of engineering to keep #1 transmitter from
blowing the socks off of the #2 receiver.

The Garmin audio panel allows two seperate conversations to take place
at the same time and if you weren't sitting right next to him you
wouldn't know he was talking on the other radio. I will have to tune in
the ATIS on one radio and see if by transmitting on the other if that
mutes the ATIS in my headset.