[OZAPRS] Strange APRS packets

Gordon VK4VP gordon.t at internode.on.net
Tue Dec 27 09:32:43 EST 2011

Hi all,

            I too have been seeing these strange events but I can see them
on UI-View as what looks like multiple tracks on the map.


This happened once before and the problem was my TNC.  I was running an
MFJ-1270B in KISS mode and rebooting the PC fixed the issue.


We worked this out by disconnecting my Igate from the server and the problem
was solved.


I no longer use the 1270B but use a TNC-X in KISS mode.


I have just reset it all here so we will see how it goes.


VK4OG and I often can hear the same packets on RF so it is possible if I
have an issue it could cause this problem.


I am also guessing that the TCPIP originated packets are reverse gated
packets from VK4OG.


P.S  Philip don't worry about saying what you see or if there is an issue,
we don't always know what's happening unless someone tells us. 



Regards Gordon VK4VP



From: ozaprs-bounces at aprs.net.au [mailto:ozaprs-bounces at aprs.net.au] On
Behalf Of Philip Webb
Sent: Monday, 26 December 2011 21:48
To: Australian APRS Users
Subject: Re: [OZAPRS] Strange APRS packets



Actually, I'm glad this subject has come up, because I have been noticing
issues for a while and not sure how to broach the subject.

Out here in the country, I often see posits going straight to tcpip only -
no problem. Occasionally I see a mixture of both, and most of the time that
is understandable. But occasionally I see things that don't make any sense.

Neither my car nor David's is fitted with 3G mobile yet many of our trip
have posits marked as TCPIP with the original VHF path lost - short example

2011-12-02 13:17:38 UTC:
2011-12-02 13:17:38 UTC:
2011-12-02 13:19:38 UTC:
2011-12-02 13:21:37 UTC:

The TCPIP packets are always attributed to VK4OG and has only been happening

I also noted anomalous activity similar to David's on Saturday 24 th, with
the duplicate "position" packets and posits moving too fast - but I won't
spell out any further details except to say that the anomalous packets are
also related to VK4OG and VK4VP.
I have analysed some of the duplicate "position" packets, and they have been
repeated up to 6 minutes later than the originals and have "WIDE1*,WIDE2-2"
modified to "WIDE1,WIDE2*".

If anyone would like to have a look at the chapter and verse, please contact
me off list.

I'm just trying to help sort out a fine system which has been working well
up to now.

Tried your site Damien, but it timed out and I did get my data from aprs.fi

I hope you all have a great New Year.



On 26/12/11 18:40, Damien Gardner Jnr wrote: 

I'm guessing that you're referring to the 'duplicate position packet'
messages?  You didn't actually say what the 'strange behaviour' actually was
That would appear to be a problem upstream from .au, as it's *not* appearing
on the second.aprs.net.au data stream..  Check out
http://hamtrack.pinegap.net/stationdump.php?stationid=42434 for your raw
packet dump for the last 24 hours - you'll see that there were no duplicates
in there, so any 'duplicates' that aprs.fi may have seen, were in the global
network, not .au..
-----Original Message-----
From: ozaprs-bounces at aprs.net.au [mailto:ozaprs-bounces at aprs.net.au] On
Behalf Of David Hopkins
Sent: Monday, 26 December 2011 2:15 PM
To: ozaprs at aprs.net.au
Subject: [OZAPRS] Strange APRS packets
Anyone else noticed strange behavior on the APRS system here,
Have a look at the raw packets on VK4zf-9 on aprs.fi At first I thoughht
there was something wrong with the setup in this car.
However if you look at vk4zf-7, it has the same problem.This is a completely
different car and radio.
I have noticed it also on other mobiles.
If you watch the tracks on aprs.fi the positions are all over the place.
What is going on?
David G. Hopkins (VK4ZF)
27.32.38S 153.12.03E
Skype :- davhop 
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