[aprssig] Pocket Tracker???

Robert Bruninga bruninga at usna.edu
Sat Nov 19 16:49:51 CST 2005

>That's why I brought up the issue of multiple input channels.  
>Having several inputs and a reasonable slot selection 
>scheme would give you more reliable operation than 
>single-channel ALOHA, given the hidden transmitter
>problems in APRS.

Yes, We have had an alternate 144.99 input channel in
my area for a few years now (call is 99ANAP), but doing
a FINDU search I can find not one single other 144.99
input digi anywhere.  This assumes that all such digis
use the suggested naming convention of "FFxxxx" where
FF are the digits best representing the alternate freq.

The biggest advantage for the alternate input channel
was in letting the flea powered pocket trackers operate
without contention on their own uplink, but now that
the pocket tracker is gone, there is somewhat less

However, the biggest incentive would be for those
areas of APRS local club activity that want to have lots
of trackers running around but do not want them to have
to compete with all the out-of-area APRS traffic passing
over them.  In this case, the alt-input channel is IDEAL.
The club can do special events anytime they want and
be assure that their trackers will get thorugh locally.

An ALT-INPUT digi works by listening on 144.99 and
digipeating over to 144.39 so that these trackers 
tracks join in with traffic on the main channel, but
with local priority.


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