[aprssig] APRStt Voice Channel outside the box

Duane Whittingham n9ssn at arrl.net
Sun Oct 12 16:21:55 EDT 2008

I also want to point out that if one can afford to get a UMPC like an 
EEEPC or some of the small laptops they wont take up much room or power.  :)

Duane - N9SSN

At 03:00 PM 10/12/2008, you wrote:
  ... It would cost a minimum of +/-$300
  per repeater to add APRStt hardware,....
  virtually unattainable by the vast majority of hams.
  doesn't this make APRStt an  unrealistic concept, at
  least on the universal scale? 73 de Rod.

I guess it depends. Here are some thoughts...

1) actually, we are now thinking less about putting these at
repeaters and more like putting them wherever convenient and
locating them on a simplex frequency.  Their main application is
for events, situations, and activities, where they can be
located as easily as a laptop and HT for the duration of the

2) And having a common simplex channel to monitor has a lot of
merrit.  Initially I suggested 147.51 but someone pointed out
that is not available in Texas and ALA and other states that
went to 20 KHz spacing. With that restriction, we need to look
at 146.46, 146.58, Or maybe 147.42, 147.48, or 147.54.  OK, lets
start with 147.54... Any conflicts?

3) Cost should be near nothing.  APRStt needs only an old radio
and an old PC.  Old PC's are everywhere.  Old radios in the
shacks and basements of most hams are gathering dust and also
relatively available.  The version of APRStt in work I believe
runs on a PC as an add-on to Uiview, so anything that can run
Uiview should be able to run APRStt.

4) Only one permanent APRStt system needs to be installed in the
area, since all hams can then use it at no cost to themselves.
(they already have the DTMF HT's and radios).  Of course if it
is not high at a site similar to a repeater site, then it may
not have much coverage and we will need a lot more of them.  And
you are also right, that adding a simplex system at an existing
repeater site is not trivial if done correctly...

Anyway,  one aspect of ham radio is as a place to experiment and
to try new things using what they have.  I imagine you are right
that if somene had to go buy a PC just to run APRStt, and buy a
radio, then one could say the cost could easily be even more
than $300.

I cant wait to give it a try.
I will put up a node in downtown Annapolis from my office.
Range will be small, but it will serve the handheld user in the


  Original Message -----
  From: "Robert Bruninga" <bruninga at usna.edu
  To: "'TAPR APRS Mailing List'" <aprssig at lists.tapr.org
  Sent: Friday, October 10, 2008 6:33 PM
  Subject: [aprssig] APRStt Voice Channel outside the box

  I think people still miss the point of APRStt.
   They are thinking inside a DTMF box.

   Quite conversly, what users of APRStt (the other 95% of your
   club) will experience mostly has nothing to do with DTMF.
   simply tune into the APRStt channel and "listen" to APRS
   information in the immediate local area.  For example at a
   marathon where the lead vehicle has the call LEAD you will
   once a minute:

   "LEAD is 4.5 miles northeast of FINISH"  or
   "TAIL is 3.5 miles south of START"  or
   "W1VIP is .1 mile west of EOC"

   And you will never hear a LAT/LONG.  Positions are reported
as a
   distance in a direction from the reference point.  The
   point defaults to the APRStt gateway location, but the
sysop, or
   any APRStt user can change the reference point to anything
   in APRS by simple command.. such as "from the repeater" or
   downtown" or "from FINISH", or from any other APRS station.
   With this powerful technique, it is very easy to visualize
   tactical situation.

   Remember, with only a few key presses such as QNM APRStt
   respond (by voice) with the nearest MOBILE to you...  Or QNW
   will be the nearest Weather to you... Etc..

   In a general purpose community APRStt for your club,  here
   some examples of some of the unsolicited information that
   might hear (if enabled):

   - An APRS mobiles voice FREQ  if he has it in his beacon
   - the local recommended voice freq object for travelers
   - the location and speed of some special stations.
    A) Any TH-D7 that selects the  TRIANGLE ICON
    B) Any D700 or APRS mobile using the "/n" ICON
    C) Any one station enabled by the APRStt sysop or DTMF user
   - the location of any new CALL that comes into the area
   - the AZ & EL & Frequency of any satellite in view
   - the TRAFFIC Speed past any TRAFFIC choke point...

   So, think outside of the DTMF box!  APRStt is more about
   the other members of your club or community "receive"(hear)
   local APRS information of immediate interest than it is
   entering anything in DTMF.

   Imagine the possiblities for your next event (for both the
   information) and for the remote data entry by anyone with an
   or for just providing local info of value to voice mobiles
on a
   routine basis when you cannot raise anyone on the local

   The info on the original APRS Traffic monitoring system is

   And APRStt is on www.aprs.org/aprstt.html

   Bob, WB4APR

Amateur Radio Operator
Duane Whittingham - N9SSN
City of Chicago CERT Member
Red Cross Disaster Services Technology Member
Red Cross ECRV Certified 

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