[aprssig] APRStt (APRS touchtone DTMF)
vk2tv at exemail.com.au
Fri Sep 19 16:52:06 CDT 2008
Robert Bruninga wrote:
>> How are you going to differentiate the DTMF
>> tones used for this from the repeater control tones?
> Good questions. I have tried to get people who know these codes
> to provide the best recommendations. Best we have come up with
> is to begin each APRS string with ##A or ##B or ##C depending of
> the APRS application. The ## in many repeaters tells the
> repeater to ignore the following tones. THen two of them
> improve that probabilty of detection. The A or B or C indicates
> the type of APRS code to follow...
Guard the repeater control functions with a unique CTCSS tone and a bit
>> 1. Most repeater owners who use DTMF control
>> guard them very carefully. One wrong tone can
>> cause the repeater to go crazy, meaning you
>> might have make a trip to a mountain top
>> or restricted access building. They are not
>> universal, and many poeple will be suspicious
>> if you ask for them out of the blue.
> Yes, only the existing repeater sysop knows if this application
> will be good on his repeater or better to be placed elsewhere.
> There are so many unused repeaters, that there are plenty of
> places to put them. Actually, APRStt was mostly designed for
> its own frequency at an event or special purpose. It should not
> be placed on a repeater that would have problems for it.
>> 2. Some repeaters strip DTMF off, others do not...
>> 3. How will I know if a repeater in an area
>> uses this? Is this going to be in ARRL
>> repeater directory, or sent on APRS?
> Yes, it will show up on every APRS map, or FINDU, or whatever.
> The APRStt engine will appear on all maps with its special
> APRStt symbol and frequency so that everyone can tell where it
> is... But of course the DTMF user doesn't see the local APRS
> map, so you are right, it will be in directories, and it should
> be included in the voice announcement.
>> I don't think you want to just blindy try
>> sending DTMF on a repeater without asking
>> a local user.
> Yes, that is a big concern. These are all issues we need to
> deal with, but at least now finally we have the mechanism. Now
> we see how to implement it..
> Glad to have you on board and helping...
> Bob, WB4APR
>> Re: [aprssig] APRStt (APRS touchtone DTMF)
>>>> APRStt coming soon!
>>>> but this will be a new version that
>>>> runs under windows using only the sound
>>>> card for both DTMF decoding and Voice-Back synthesis.
>>> Ehhh...is this going to be available on platforms
>>> that are suitable for unattended operation? (sigh)
>> See www.aprs.org/aprstt.html
>> Bob, WB4APR
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