[aprssig] Duplicates evident on aprs.fi

[Gerard Hill]

On 27/06/2011 8:07 AM, Rob VK6UFO wrote:
> On 26/06/11 19:25, Heikki Hannikainen OH7LZB wrote:
>> I looked up the packets on aprs.fi. The packets have been modified by
>> a digipeater or an igate, either by adding or by removing a space
>> character in the end of the packet. Since the packet contents differ,
>> they're not treated as duplicates by the APRS-IS, and they're not
>> filtered.
>
> Yes, that seems to be the answer. The packets in question all have
> trailing spaces until they pass through one igate where the spaces
> disappear. I believe the spaces are part of the OT reporting temp and
> voltage in the comment so removing it would require turning off the
> reporting or adding something extra to the comment. As far as I can
> tell, the igate in question is using APRSISCE win32 (APWW08)

The same thing is happening on the east coast with posits from my VX-8R. 
Packets have a 17 byte payload with 2 spaces on the end. There are often 
TWO repeats, one with a space stripped, and another with 2 spaces 
stripped. Here's how they appeared on aprs.fi in hex mode:

2011-06-25 10:05:23 UTC VK2IO-7: 61 bytes
0x00 V K 2 I O - 7 > S S 4 4 W 2 , V K 2 R U W - 1 * , W I D E 2 - 1
       564b32494f2d373e5353343457322c564b325255572d312a2c57494445322d31
  0x20 , q A R , V K 2 H I M - 1 : ` O X # n \ ? [ / ` " 5 . } _
       2c7141522c564b3248494d2d313a604f58236e5c3f5b2f6022352e7d5f

2011-06-25 10:05:25 UTC VK2IO-7: 71 bytes
0x00 V K 2 I O - 7 > S S 4 4 W 2 , V K 2 R U W - 1 * , V K 2 R A O -
       564b32494f2d373e5353343457322c564b325255572d312a2c564b3252414f2d
  0x20 1 * , W I D E 2 * , q A R , V K 2 A S Y - 1 : ` O X # n \ ? [ /
       312a2c57494445322a2c7141522c564b324153592d313a604f58236e5c3f5b2f
  0x40 ` " 5 . } _
       6022352e7d5f20

2011-06-25 10:05:26 UTC VK2IO-7: 70 bytes
0x00 V K 2 I O - 7 > S S 4 4 W 2 , V K 2 R U W - 1 , V K 2 R T Z - 1
       564b32494f2d373e5353343457322c564b325255572d312c564b3252545a2d31
  0x20 , W I D E 2 * , q A R , V K 2 Z E N - 5 : ` O X # n \ ? [ / ` "
       2c57494445322a2c7141522c564b325a454e2d353a604f58236e5c3f5b2f6022
  0x40 5 . } _
       352e7d5f2020

It's no surprise that aprs.fi reports that packets are being sent at a 
high rate!

Cheers ... Gerard, VK2IO