[aprssig] APRS in gliders

Rikard Sohlberg rikard.sohlberg at home.se
Fri Apr 6 16:10:35 CDT 2007

I now have a PocketTracker permanently mounted in my glider (sailplane).
This means I will be beaming my position, speed, course and, most important
in gliders, altitude, on every flight this summer. I spent the last week in
Norway in a wave soaring camp (www.wavecamp.no). Unfortunately, the weather
was not all that cooperative, but I got on flight up to an altitude of 3000
meters (or 10 000 ft as Americans prefer to call it... ;-). Also a little
unfortunate was that the local ham (whose call sign I forgot) was not active
this year, so I-gateing was a problem. We discovered that the range from the
PocketTracker with a 50 cm wire antenna was about 20 kilometers (?? miles)
to the TH-D7 down on ground (or actually the (frozen) lake) we were flying
from. Up to that, all packets decoded perfectly, after that, some were heard
but did not decode. The TH-D7 was just using the original rubber antenna.
But from 3000 meters, a few packets hit some I-gates some 70 kilometers to
the south and my buddies back home in Sweden could see me.
I was also invited by the camp management to give a presentation on APRS!
This was very nice and gave me an opportunity to explain the magic of APRS
to an interested audience of some 20-25 highly motivated and technically
savvy pilots. One guy (a KLM 747-400 captain) asked me a few question after
the presentation and said his son was a ham. He would probably do some
experiments from his Club Libelle glider.
Also the capabilities of weather reporting are of great interest to the
glider community. As we are very dependant on the weather (our "engine"),
the ability to send and receive real-time weather information is also of
great interest. As this is an area that I have not explored myself, I did
not elaborate on that in m,y presentation.
After the presentation, it struck me that if I just had prepared myself a
little better, I could have demonstrated map tracking on the ice with my
laptop, UI-View and the TH-D7 as TNC. I just did not grasp that idea. It
would have worked, at least as long as the laptop battery!

Of course, I'm also interested in other experiences from flying APRS hams,
powered, or non-powered alike! My glider actually is a powered glider, a
so-called SSG, Self Sustaining Glider. A little two-stroke that can take me
home if the thermals lets me down(!).
Here is a picture of my glider (and SM0JWX in the cockpit!): 
http://www.pilotmagazinet.se/search.asp?search=SE-UNA I use the registration
SEUNA as tactical call sign with my call sign in the status message. We also
fly SEUNF and SEUCS in my club.

OK, sorry for long mail, but I got inspired by Bob's mail on doing things!

73 to all



(If you wish to contact me off-mail list, I use Rikard.sohlberg at home.se) 

-----Ursprungligt meddelande-----
Från: aprssig-bounces at lists.tapr.org [mailto:aprssig-bounces at lists.tapr.org]
För Bob Bruninga 
Skickat: den 30 mars 2007 05:16
Till: TAPR APRS Mailing List
Ämne: RE: [aprssig] Two More Tier 2 Servers for your use!

> While there has been great debate over the pros and
> cons of [tier1 and tier2 systems] it remains simply 
> a CHOICE for APRS operators.
> Sometimes having a CHOICE isn't a bad thing.

And dont forget the third choice which is to CONNECT A RADIO!
Operate APRS the way it was intended.  A local real-time tactical RF network
informing everyone in the local area about everything going on in Ham radio
live and now, right outside your shack...

If nothing is going on, then do something in Ham radio.  APRS is not an end
in itself.  It is just a single common signalling channel anywhere and
everywhere to share HAM radio in real time so that everyone is informed on a
single channel of anything that might be happening (all around on any other
freq, or band or what-have-you).

If you are doing something in ham radio that anyone else might be interested
in, put it out on APRS. An object, A bulletin, A location, A freq, an area,
a heading, a bearing, a meeting, a net, some DX, some news, etc... APRS was
never just a vehicle tracking system.  Its too bad that is all most people

Is it because no one is doing anything else in Ham radio?  No, its because
we arent remembering to use this common channel to inform others of
everything going on..  We can do better.  And I DONT mean 24/7 bulletins and
24/7 objects and 24/7 SPAM spread far beyond the local area.

Dont miss the local trees in your RF domain because of the global APRS

Sorry, I ramble...

In ANY case I highly recommend that you have more than one server for your
APRS program to attach to. I've seen cases where an ISP lost a lot of their
direct connectivity to the West but kept a connection to the East. While
that shouldn't be enough of a drop in the ISP's bandwidth to kick you off an
APRS server, Murphy is always waiting in the wings.

> -----Original Message-----
> From: aprssig-bounces at lists.tapr.org
> [mailto:aprssig-bounces at lists.tapr.org]On Behalf Of Jack Chomley
> Sent: Thursday, March 29, 2007 4:02 PM
> To: TAPR APRS Mailing List
> Subject: Re: [aprssig] Two More Tier 2 Servers for your use!
> Alright, when it comes to APRS infrastructure....I know nothing.
> What, is a
> Tier 2 server? I go and have a look at the links and simply see a whole
> stack of statistics and thats it! No support pages, no "how it works"
> pages. At least at findu.com I can find "myself" :-)
> 73's Jack VK4JRC-15 HF APRS Motorcycle mobile
> _______________________________________________
> aprssig mailing list
> aprssig at lists.tapr.org
> https://lists.tapr.org/cgi-bin/mailman/listinfo/aprssig

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