[aprssig] KPC3+ induced errors

Wed Mar 16 12:46:47 EDT 2011

Randy, et al;

You asked about the Igater that was using the Kenwood D710 on the EOSS
flights Saturday.  It was Mark, KC0D, a well know and very competent HAM.
He was running his Igate unattended as he was out in the field as part of
the Tracking and Recovery team.  We have had conversations about this issue
and he is at a loss for what is happening as are we all.

Here is a snapshot of the telemetry from EOSS-159, the first flight of the
day.  Mark's Igate is kc0d-3 in the snapshot.  I haven't broken out the
delays to measure the delay time, but I don't think it matters as there is
an obvious problem that can be seen in the time stamps and the altitudes
reported.

KC0YA-11>APRS,EOSS,qAR,KC0D-3:$GPGGA,135316,4028.3444,N,10457.8329,W,1,08,1.
00,1950.0,M,-21.0,M,,*77 

KC0YA-11>APRS,EOSS,qAR,KC0VJE:$GPGGA,140228,4027.8067,N,10453.3921,W,1,10,0.
75,5529.5,M,-21.1,M,,*7D 

KC0YA-11>APRS,EOSS,qAR,KC0D-3:$GPGGA,135346,4028.3376,N,10457.8609,W,1,08,1.
00,2131.5,M,-21.0,M,,*7A 

KC0YA-11>APRS,EOSS,qAR,KC0VJE:$GPRMC,140345,A,4027.8407,N,10452.4600,W,38.17
4,92.0,120311,10.1,E*5B 

KC0YA-11>APRS,E4,1,qAR,KC0D-3:$GPGGA,135446,4028.3581,N,10427.
394,W,1,04,1000,2502.4,M,-21.0,M,,*77 

KC0YA-11>APRS,EOSS,qAR,KC0VJE:$GPGGA,140346,4027.8401,N,10452.4458,W,1,10,0.
75,6083.8,M,-21.2,M,,*7D 

KC0YA-11>APRS,EOSS,qAR,KC0VJE:$GPGGA,140416,4027.8211,N,10452.0300,W,1,09,0.
84,6312.9,M,-21.2,M,,*7A 

KC0YA-11>APRS,EOSS,qAR,KC0D-3:$GPGGA,135516,4028.3293,N,10457.7954,W,1,08,1.
00,2685.6,M,-21.0,M,,*70 

KC0YA-11>APRS,EOSS,qAR,KC0VJE:$GPGGA,140446,4027.7923,N,10451.6041,W,1,09,0.
84,6543.1,M,-21.2,M,,*73 

KC0YA-11>APRS,EOSS,qAR,KC0D-3:$GPGGA,135616,4028.2413,N,10457.4481,W,1,08,1.
00,3088.6,M,-21.0,M,,*70 

KC0YA-11>APRS,EOSS,qAR,KC0VJE:$GPGGA,140516,4027.7330,N,10451.2199,W,1,09,0.
84,6778.6,M,-21.2,M,,*72 

KC0YA-11>APRS,EOSS,qAR,KC0D-3:$GPGGA,135646,4028.1630,N,10457.1639,W,1,08,1.
00,330302,M7-21.0,M,,*74 

KC0YA-11>APRS,EOSS,qAR,KC0D-3:$GPGGA,135716,4028.0831,N,10456.8637,W,1,08,1.
00,3504.5,M,-21.0,M,,*7F 

KC0YA-11>APRS,EOSS,qAR,KC0VJE:$GPGGA,140546,4027.6844,N,10450.8156,W,1,09,0.
84,7006.8,M,-21.2,M,,*77 

KC0YA-11>APRS,EOSS,qAR,KC0D-3:$GPGGA,135746,4028.0183,N,10456.5880,W,1,09,1.
00,3696.2,M,-21.0,M,,*7B 

KC0YA-11>APRS,EOSS,qAR,KC0VJE:$GPGGA,140616,4027.6686,N,10450.3824,W,1,09,0.
84,7235.4,M,-21.2,M,,*78 

KC0YA-11>APRS,EOSS,qAR,KC0D-3:$GPGGA,135816,4027.9335,N,10456.3068,W,1,09,0.
94,3873.4,M,-21.0,M,,*7F 

KC0YA-11>APRS,EOSS,qAR,KC0VJE:$GPGGA,140646,4027.6706,N,10449.9278,W,1,09,0.
84,7460.5,M,-21.2,M,,*72 

KC0YA-11>APRS,EOSS,qAR,KC0D-3:$GPGGA,135846,4027.8498,N,10456.0181,W,1,09,0.
94,4055.8,M,-21.0,M,,*79 

KC0YA-11>APRS,EOSS,qAR,KC0VJE:$GPGGA,140716,4027.6662,N,10449.4959,W,1,09,0.
84,7686.8,M,-21.2,M,,*77

From: aprssig-bounces at tapr.org [mailto:aprssig-bounces at tapr.org] On Behalf
Of Randy Love
Sent: Wednesday, March 16, 2011 5:18 AM
To: TAPR APRS Mailing List
Subject: Re: [aprssig] KPC3+ induced errors

On Tue, Mar 15, 2011 at 11:08 PM, Larry Cerney <lcerney at viawest.net> wrote:

Now there's nothing to say that there ISN'T a problem with the KPC3+/KISS
mode, but the errors were traced to an Igate who was running a Kenwood D700
into a computer running UI-View.  No KPC3+ involved at all.  His packets
were being delayed by 2 to 10 minutes.  Russ, KB0TVJ, has done some analysis
on the timing, so I'll like him explain that.

But it seem the packet delays are due to something that is happening with
KPC3+ and now the internal TNC in the Kenwood D710, or something common to
both, or something altogether different.

Are you absolutely sure that it was the D700/UI-view32 combo that was
delaying them and not an upstream digi that is some client using a KPC3+ in
KISS mode?

I have a hard time believing the D700 has the same issue. They are TASCOM
modems and are not based on the Kantronics design.

What is the call of the suspected Igate? I'd like to see packets it delayed
that were not digi'd by another station proir to it gating them to APRS-IS.
If it was digi's by anything else, then the assumption can be disputed.
Also, the KPC3+ delays are consistent -- once it starts doing it, it keeps
doing it until reset or power cycled. It sounds like you are saying the 2 to
10 min delay with the D700 is random. 

Just my opinion.

Randy
WF5X

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.tapr.org/pipermail/aprssig_lists.tapr.org/attachments/20110316/3f60f07a/attachment.html>