[aprssig] -IS to RF Igating (was: APRS on Android)

[Stephen H. Smith]

On 1/24/2011 2:07 PM, Eric Lorenz K9LGE wrote:
> Hi Lynn:
>
> I run under K9LGE-10 on my Droid X.
>
> The only other drawback is since data and phone cannnot run at the same time, 
> I have to re-enable APRSDroid after I get a call (unless I have something set 
> incorrectly and it is supposed to do it automatically). So, when I am on the 
> phone a lot in the car, I won't run it.
>
> (The other was a failed experiment to setup a local fill-in digi...discovered 
> there *was* another digi in the area so mine didn't seem to be needed).
>
> A little background...I travel over a lot of the midwest, primarily between 
> IL and WI and MN. I have been told that because of the amount of APRS traffic 
> on the network in WI, I probably would have next to no luck in asking ops to 
> reverse Igate...so I guess I will have to save my nickels for a better 
> radio-based APRS-solution. My current setup uses a Kenwood TM-251A fed from a 
> Garmin eTrex via a KPC-3. 

Arrrgh!!!    You are transmitting raw NMEA strings with this setup -- a 
horrible waste of air time in urban areas.   Raw NMEA sentences are 3 times 
longer than standard APRS-format strings and TEN times longer than compressed 
Mic-E format posits.  [The KPC3 in tracker mode transmits the 100+ character 
NMEA string received from the GPS as-is without reformatting it.]

Not only are you needlessly taking up more air time than required; you are 
shooting yourself in the foot by absolutely minimizing the chance you will be 
heard!    Bear in mind that ALL of a packet must be heard  PERFECTLY before 
ANYTHING can be recovered from it.
The long raw NMEA packets have a far far higher chance of being stepped on by 
another station transmitting at the same time, or getting corrupted by mobile 
flutter or a pop of noise.       Consider substituting a  $33 TinyTrak III 
(which can generate short-form APRS posits or Mic-E format), and then use the 
KPC3 as a send/receive TNC under software control at home.

TTIII Info: <http://www.byonics.com/tinytrak/>

> I would prefer to have this to use for a digi, or for packet use, but It's 
> all I have right now. I was trying APRSDroid to avoid having to run both 
> radios in my van while I am traveling.
>


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Stephen H. Smith    wa8lmf (at) aol.com
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