[aprssig] Error checking within APRS packets

[Keith VE7GDH]

Max KG4PID wrote...

> There is an Igate in my area that changes the callsign of some of the
> packets that it gates. The Igate is KG4NVN-13 and I notified him a
> few days ago about it via email and was told that he would take it
> off line to check it out...

www.db0anf.de/app/aprs/stations/digiusers-KG4NVN-13

There appear to be quite a few corrupted callsigns handled
by KG4NVN-13. Having PASSALL enabled is the usual culprit
but I have heard of RF getting into a TNC and causing errors,
obviously after all of the CRC checking, so presumably in the
serial connection between the decoder and the receive data out
on the serial port.

Checking PASSALL should only take a moment. Unless antenna
was very close to the TNC, or unless the SWR was terrible, there
shouldn't be a lot of RF floating around near the TNC.

Looking at some of the callsigns viewed on the "digi users list"...

http://aprs.fi/?c=raw&call=0A4BNI-3&limit=25
2011-06-15 00:28:48 UTC:
0A4BNI-3>APN382,qAR,KG4NVN-13
:!3619.69NS08917.47W#PHG5450/ W4,TNn  Hornbeak, TN

It was heard direct, so no digis between the originating station
and the iGate are implicated. The same comment also goes for

1F4Q-1, 204BNI-5, 4BNNHN-1, and BNIBNI-5.

I agree. KG4NVN-13 should check his TNC. If it is PASSALL
it is a easy fix. If that isn't it, he would have to do some digging.

73 es cul - Keith VE7GDH
--
"I may be lost, but I know exactly where I am!"