[aprssig] alt input digipeater

Stephen H. Smith wa8lmf2 at aol.com
Thu Mar 3 21:14:31 CST 2005

aprs at kd4rdb.com wrote:

>if the main digi
>squawks using 67hz, that you are in an area that has 144.99 alt input.  I'd say
>do this with the actual alt input transmitter, but it would TX so infrequently,
>you could pass thru an area w/o ever hearing it.
The alt input, as envisioned in this scheme, wouldn't have a separate 
transmitter.  It 's just a second receiver and TNC sharing the 144.39's 

>By doing this, the people running no receive trackers such as tiny trak could
>monitor 144.39 for 67hz and know that they could QSY to 144.99 with their tiny
>trak rig...  
This would work for a TinyTrak connected to a transceiver, but it 
assumes the radio has PL <ON RECEIVE>. A lot  of the junker-clunker 
hand-me-down older 2M rigs that get pressed into service as trackers may 
have PL encoders on transmit but most don't on receive.   It won't work 
at all for a PocketTracker which has no receiver at all.    The original 
concept of this alt freq scheme was to give the LOCALS with low-power 
trackers a fignting chance against out-of-town long-path QRM and 
high-power mobiles. It was not intended to support the itinerant passing 
through.  I think the idea is that the locals would find out through 
other channels, such as beacons on 144.39, local clubs, or this list.

Stephen H. Smith             wa8lmf (at) aol.com
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