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[aprssig] New and playing

Keith - VE7GDH ve7gdh at rac.ca
Thu Nov 18 20:31:38 UTC 2004


Bob WB4APR wrote on 18/11/2004 11:03:35 AM

> But *every* digi is supposed to also respond to RELAY and
> do callsign substitution... so it should not matter where one
> is when using that path.  The problem with trackers is 100%
> congestion  on the inputs of most digis who are hearing all
> the QRM from the surrounding 300 miles.  That's why
> separating the local user inputs to 144.99 (if available
> in your area) is the way to solve that problem...

In areas where there are high elevation WIDE-n-n digis, but where there are many low elevation RELAY digis, maybe it would be a good thing if the high elevation digi did NOT respond to RELAY. This will very in every geographic location, but it's just a thought.

Why blame the trackers? QRM is QRM, whether it is caused by transmitters running too high a power, abusive paths, or just plain transmitting too often. You aren't suggesting that just the trackers should move to another frequency, are you? Maybe the concept of alternate frequencies will catch on, but it would be nicer if everything can work on 144.390 MHz... unless we move to frequency-agile radios that are capable of adjusting their power output on the fly. Maybe the device running the show can even be made smart enough to intelligently change the path based on what digis it is hearing, but that's a future concept and not today's reality. For now, I think we should concentrate on user education.

More "future concepts"... let's move to a duplex system. Everyone transmits on the "input" frequency. Digis receive on the end users transmit frequency. The digi then transmits on the "output" frequency.  Because only it (and it's neighboring digis) are transmitting on the "output" frequency, there will be less packet collisions there. There will still be collisions on the input frequency, but at least (hopefully) ONE of the beacons heard by any given digi would be transmitted on a relatively quiet channel. Just another thought...

73 es cul - Keith VE7GDH
--
"I may be lost but I know exactly where I am"





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