If you need some additional range on your Bluetooth headset, here's a
thread describing a way to get it that works very well.
The only real tough part is finding enough space inside the intercom
to install that audio jack and switch. I had a tough time just
finding room for the jack. The switch was out of the question so I
used a normally closed switched jack. I think there may have been
some change in the design of the case between the one he did and the
one I did or else he's a magician.