[aprssig] TT4 Config for High Altitude Balloon

Stephen H. Smith wa8lmf2 at aol.com
Sun Apr 8 20:10:59 CDT 2012

On 4/8/2012 8:27 PM, John Gorkos wrote:
> Digi path should just be WIDE2 (next flight, we'll have a more intelligent 
> controller with altitude-variable digi paths).

Arrrgh!!!!!      NO!   At the most, only WIDE2-1 -- if any path at all is to be 
used.    You will almost guarantee the buggy KPC3 delayed packet problem by 
blasting WIDE2-2 over the vast area reachable by two hops from altitude.

This is the infamous bug where KPC3 TNCs being used in KISS mode as igates 
randomly delay received packets for several minutes before forwarding them to 
the attached computer (and then to the APRS-IS).  The result is old posits 
arriving on the ARPRS-IS  long after new ones, causing the position and 
altitude of the balloon to "hyper-jump" back and forth and up-and-down.

The larger the area you spray posits over (and therefore the number of igates 
you are likely to hit simultaneously (where some will be buggy KPC3s and some 
not),  the more likely this problem is to occur.



Stephen H. Smith    wa8lmf (at) aol.com
Skype:        WA8LMF
Home Page:          http://wa8lmf.net

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