Perhaps one the remaining contributions we could make as amateurs would be working with DSP to combine all these attributes in a standalone uP module. It would be great to have an adaptive squelch board for retrofit into repeaters which could account for multipath, propagation conditions, noise levels, and user priorities.
It will probably fall to us to do it, because we'll no doubt be the last users of analog NBFM. Besides...those Micor squelch chips won't last forever! 73, Paul, AE4KR ----- Original Message ----- From: ka1jfy To: [email protected] Sent: Friday, August 21, 2009 5:16 PM Subject: [Repeater-Builder] Re: Squelch action on 10 m FM Because CTCSS falses on the random noise. Been there, done that, gave away the t-shirt. WalterH --- In [email protected], n...@... wrote: > > At 8/20/2009 23:17, you wrote: > > > >John, how's this for an experiment... > > > >Configure a repeater with two receivers, one built for +/- 5 kHz > >deviation, the other for +/- 15, feed them from a splitter, use audio from > >the narrow one, but allow a DTMF command to select the wider receiver's > >COS when conditions warrant. (Obviously, those conditions would have to > >include no adjacent channel signal...) > > If noise squelch is so problematic in severe multipath conditions, why not > do away with it entirely & use straight CTCSS squelch? The GE decoders > that use Versatone chips are fast enough that you can still almost > eliminate the squelch tail with an ADM. > > Bob NO6B >
