[aprssig] APRStt question

Robert Bruninga bruninga at usna.edu
Sat Feb 11 11:00:56 CST 2017

Since An APRStt (DTMF) transmission is converted to APRS at the local VHF
receiver, there is no need to encode the full DDMM.mmN/DDDMM.mmW plus the
ten digits needed for the callsign. (35 digits) when the VHF receiver
already knows where  it is, it already knows the DDMM and DDDMM digits.  SO
the DTMF user only needs the four mmmm digits to give a precise position
(60 feet)  report at a 1 mile event area such as dayton.

Or the Mm/Mm four digits to give 600 foot precision within 10 miles of the

By keeping the significant digits to 4, thusly, we can encode both the
callsign and relevant position in the 16 digits of most DTMF memories,
while still giving all APRS functiionality.


On Fri, Feb 10, 2017 at 8:37 AM, Bob Mueller <bob at funautical.com> wrote:

> I just read over:
> http://aprs.org/aprstt.html
> http://aprs.org/aprstt/aprstt-user.txt
> Are there any standard position formats as part of APRStt?  It seems that
> the positions are only "proprietary" to the user.  By using their own map
> grid or y,x position from a known fixed point.  It does not appear that
> there is any way to encode a lat/lon.  I don't see anything in the
> documentation that indicates a maidenhead locator is resolved to lat/lon
> and then digipeated.
> That leads me to my next question that I believe I already know the answer
> to:  Is there any way to use APRStt to create APRS objects?  It appears the
> answer is no.  As it only supports A, B, C, D. Callsign, Position, Comment,
> Messages respectively.  No objects.
> Please confirm that I have this correct and I'm not missing something.
> --... ...--
> Bob Mueller
> K8MD
> bob at funautical.com
> _______________________________________________
> aprssig mailing list
> aprssig at tapr.org
> http://www.tapr.org/mailman/listinfo/aprssig
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