Hi Nick,
I just bought a second transmitter at Thomann.de for the reason you describe; two guitars, one receiver.
But the new transmitter doesn't connect to the receiver. I tried every channel, new batteries, but no signal...
What could be wrong?
Kind regards,
Cris van Eijk
Netherlands
Picture of both transmitters: https://goo.gl/photos/P5WJJ3ECTehNCrZB6