[aprssig] Voice Repeater Frequency Objects

Robert Bruninga bruninga at usna.edu
Wed Sep 17 08:32:05 CDT 2008

>>> I maintain that xastir is not broken, 
>>> because it meets the published spec.
>> It does until it inserts the /A=xxxxxx 
>> in front of all other user text and pushes 
>> that user formatted text to the right.
> The spec says /A=12345 goes anywhere in the 
> comment, period.

Agreed.  Perfectly true.... 

> At the beginning of the comment near the 
> other two dimensions of positional
> data seems like a very logical place to me.

Yes, that is perfectly fine too.  But *not* if the user has
entered something else that he wants to go there such as Tnnn.
The issue is that XASTIR forces /A=xxxxxx into that location at
the expense of the flexibility intended by the spec to also let
it go elsewhere so that the user can place other things there.

> The Tnnn format for specifying a repeater tone 
> is not in the spec at all, much less specified 
> as a field at a particular location. 

The APRS spect was printed in 2000.  Yet the APRS1.1 addendum in
2004 revolutionized the APRS network with the New-N Paradigm for
a muilt-fold improvement in reliability, and included provision
for DIGIpeaters to also beacon their local recommended voice
operating freqeuency.  

After much discussion on the APRSSSIG over many months, the
format of that frequency was hammered out and documented in the
www.aprs.org/APRS12.html addendum.  The addition of operating
frequency to APRS is one of the most exciting advances in APRS
in years.  It was added with 100% backwards compatibilty with
the spec.

> Tnnn is simply a particular comment convention 
> consumed by a single radio, not a standard.

I guess we disagree.  It -is- a published standard and has been
implemented in over 40% of all APRS digipeaters across the land
and Kenwood is just one of the APRS players that has picked up
on the standard and added it to their implementations.

It is good that we have discovered this minor quirk of XASTIR
and possibly other devices that forces the /A=xxxxxxx format at
a specific location at the expense of the users flexibility to
place something else there.

We recommend that any client or device that inserts the /A=xxxxx
altitude format into the packet should give the user the
original intended flexibility of the APRS spec by allowing him
the option of placing it at the front, or end, or elsewhere so
that it does not conflict with other user intent with his
comment field.

Hope that helps.

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