I have an old partner system model 103c3 the modules are models 206 ver:R3.1 & 206e ver R3.0 and I want to put music on hold. We had it before we moved into our new offices and I still have the 105A coupler but can't figer out where to plug it in??? The music source has an rca output and the coupler has a rca and a ethernet type plug on the other side. We are also interested in buying a voice mail module for it.

Thanks,

Peter