At 06:34 AM 05/12/08, you wrote: >I would recommend not using a 12.5 kHz spacing freq in this case of >a control receiever, a receiver that is only 12.5 kHz away from your >regular repeater input. > >With typical good FM analog receivers these would both have >overlapping passbands and an input signal on the repeater input >would interfer with the control input. With som many using IC type >DTMF decoders any interference, just over lapping distorted voice >would hender the decoder decoding. > >A typical UHF duplexer would have a notch wide enough for a freq >+/-25 kHz away. Know this is going to be another repeaters input, >but with some research could find is close in distance to you.
We did this years ago - and we just chatted with the adjacent channel systems owner at a coordination meeting, and made sure he didn't have a problem with it. He said "just use a different PL tone that I do, no problem, I won't even know you are there" So we DPL'd the control receiver. In fact it helped clean out the junk box - we had a cheap receive crystal that by the time it settled down (the new crystal "aging" problem) had drifted too far to bring back on channel, so we used it in the control receiver, on the adjacent channel... no, it wasn't Sentry or International... (anybody remember Cal Crystal, better known as Cal Driftal ?) Mike WA6ILQ
