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<div class="moz-cite-prefix">On 12/3/2012 12:35 PM, Jason Low wrote:<br>
</div>
<blockquote
cite="mid:CAN06BdvcP2iu9-Cg_bCSSaBVKmRSPZQ2vJUd9B+EUCTUenspAw@mail.gmail.com"
type="cite"><span
style="font-family:arial,sans-serif;font-size:13px">Take note of
the raw packets KD8GBH posted. For some reason the altitude is
occasionally being prepended with three zeroes, "pushing" the 3
least significant digits out the other side. A=111405 becomes
A=000111 in the next packet. That's why the altitude keeps
dropping to 35 meters.</span>
<div style="font-family:arial,sans-serif;font-size:13px">
<br>
</div>
<div style="font-family:arial,sans-serif;font-size:13px">The
position fix errors I'm not sure about. On the raw packets on <a
moz-do-not-send="true" href="http://aprs.fi/" target="_blank">aprs.fi</a>,
it looks like some digis/gates are trying to insert positions at
a much later time than other gates have reported the balloon at
that same location. Maybe because it's running WIDE2-1 as a
path, causing digipeats from significantly long distances to
muck up the works?</div>
<div class="gmail_extra"><br>
</div>
<br>
</blockquote>
<br>
RF distances are not the issue - the RF distance delays would be
measured in miliseconds or microseconds. Normally, the APRS-IS
will throw out duplicate packets reported by different igates within
a window of 30 seconds or so. <br>
<br>
This is more likely the infamous "delayed packet" bug in KPC3+ TNCs
operated in KISS mode. <br>
<br>
After a random period of operation, these TNCs start holding packets
and not forwarding them to the attached PC for periods of a minute
or more. The result is that they arrive at the APRS-IS far beyond
the usual 30-second dupe-checking window, and are accepted as "new"
packets even though they are stale.<br>
<br>
Kantronicss has been stonewalling this issue for years, and the bug
continues to exist even in the latest 9.x firmware. The only known
fix is to power-cycle or reboot the TNC every 12 to 24 hours. <br>
<br>
<hr width="100%" size="2"><br>
--<br>
<br>
Stephen H. Smith wa8lmf (at) aol.com <br>
Skype: WA8LMF<br>
Home Page: <a class="moz-txt-link-freetext" href="http://wa8lmf.net">http://wa8lmf.net</a><br>
<br>
High Performance Sound Systems for Soundcard Apps<br>
<a class="moz-txt-link-freetext" href="http://wa8lmf.net/ham/imic.htm">http://wa8lmf.net/ham/imic.htm</a><br>
<a class="moz-txt-link-freetext" href="http://wa8lmf.net/ham/uca202.htm">http://wa8lmf.net/ham/uca202.htm</a><br>
<br>
Vista & Win7 Install Issues for UI-View and Precision Mapping<br>
<a class="moz-txt-link-freetext" href="http://wa8lmf.net/aprs/UIview_Notes.htm#VistaWin7">http://wa8lmf.net/aprs/UIview_Notes.htm#VistaWin7</a><br>
<br>
"APRS 101" Explanation of APRS Path Selection & Digipeating <br>
<a class="moz-txt-link-freetext" href="http://wa8lmf.net/DigiPaths">http://wa8lmf.net/DigiPaths</a> <br>
<br>
<br>
<br>
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