RTCM's don't care what the frequency of operation is... just that one transmits and one receives.
Pretty much like duplexers don't care what radios are connected to them... nor does Asterisk care what equipment is on the other side of the URIx ... COR/COS, Audio in, Audio out, PTT and Ground.
It's up to you to figure out which radio gets what connection ;-)
I'm pretty sure it doesn't care what antenna is connected either. But this doesn't answer my question. Permit me to rephrase. Again. Two split-site repeaters. Each repeater receiver has its' corresponding transmitter on a geographically distant site (that's what a split site repeater is you know! ;) The sites are linked with outdoor wireless ethernet 802.11an Site "A" 6m TX 2m RX Site "B" 6m RX 2m TX Do I need two RTCMs or four? Steve