Mr. APRS Explains APRS TouchTone
David Coursey, N5FDL Wed, May 20, 2009 at 9:56PM From an email exchange with Bob Bruninga:
The simplest entry for an APRStt user who wants to report his arrival at Hamvention is to simply press his DTMF MEMORY 1. Done. This reports to his wife, or anyone else, that he has arrived at the Hamvention. Two key presses, max. Not painful at all.
Now, if he wants to report his position more accurately for some reason, then…
1) If he has a GPS, then he does not need a map. He can report his position to the nearest 60’ by just entering 2 digits of X and 2 digits of Y using the Bxxyy* format.
2) If he does not have a GPS, he can pickup the paper map and enter his position to the nearest 120 feet enering only a single digit of X and y.
3) Of course, if he has no need to enter his position, then he does not need to do anything.
In many applications of APRStt, there is no interest in position, but the more important paramater might be his voice contact fequency. Again, just like his callsign, he can have pre-stored in a DTMF memory several of his favorite operating freqs. This way, anyone needing to contact him, can see that he is * at Hamvention, * When he last reported in, and * what Frequency he is monitoring.
Does the operator have to enter his callsign and a lat/long using a DTMF pad?
Nope. The station only has to enter his callsign ONCE for the duration of his ownership of that radio. NEver again.
And in APRStt, he never has to enter his DDDMM.xx/DDDMM.yy latitude/longitude, since the RF range of APRStt will only be a few miles, the DDMM… and DDDMM parts are already konwn. Usually, only xxyy will do
And besides, if someone has a GPS -and- he wants to report his position on any radio, he should not be using APRStt, but should get an APRS tracker to do it automatically. Cost under $30.
Hope that helps.
APRStt is a means for someone without apriori knowlege to get in contact with others. It is not a tracking system.
Bob, Wb4APR
Thanks for the clarification! This is definitely something that ARES/ACS groups need to add to their bag of tricks. I am hoping to test the CSS software and will report back.
