"EDR" wrote in message ...
In article , Kai Glaesner
wrote:

What do you need? An additional portable 2-place intercom? A Y-cable
extension?

Plugging a second intercom into an existing intercom will result in
feedback if the mic plugs are plugged in.

Funny, it works just fine for me. Why would their be feedback. The intercom
looks like a headset to the the thing it's plugged into. The only real fun and
games is getting the PTT's and the squelches right if you intend to actually
use both intercoms. In my case I just plug everybody into the four place
and plug the portable into a single mic/headphone jack (just as if there was
not an intercom installed in the first place).