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[aprssig] Appalachian Trial Golden Packet!

Bob Bruninga bruninga at usna.edu
Sat Mar 14 20:54:06 UTC 2009


I just heard about SOTA, Summits on the air...
http://www.sota.org.uk/

Probably been around for years, but I don't see much down here under my rock.  But this sure excites me!  I think SOTA is a normal DX activity, but looking at it from an APRS perspective I see a great opportunity!  Maybe get the GOLDEN PACKET award!

Imagine getting an APRS packet all 2000 miles from one end of the Appalachian Trail to the Other!  We should be able to do it in about 40 hops from 40 peaks or so (every 50 miles)...

We would use the TEMPn-N digipeating that should be built into every D700 (or other portable digi). see www.aprs.org/TEMPn-N.html .

We would have to operate on something OTHER THAN 144.39, but maybe 145.01 would do.  Also we would NOT operate on the same weekend as any other SOTA acticity, since we would be shooting ourselves in the foot with RF blocking from the same hilltops.

The plan might be something like this:

1) All AT stations operate with TEMP7-7
2) This lets you see your 7 adjacent nodes in both directions
3) Being linear, there will be few dupes
4) Most stations can be just D700's acting as digis (or other temporary digi that can support TEMPn-N digipeating.
5) At each site along the way, you watch for a "golden" packet from either end (Springer Mountain or Katadin).  Then you do the following:
(a) you  capture it and save it for record purposes, 
(b) you re-INITIATE a packet from your station that regenerates the packet with your new TEMP7-7 path, but it includes a shorthand notation of all successful hops so far.
(c) The above regenerated packet will go both ways, so the 7 statiuons prior can also see that it has been picked up and forwarded along the way.

If that becomes too much congestion, then we might ask that when a packet is "regenerated", that the sending station has to change its path to DIGI1,DIGI2,DIGI3,TEMP4-4 to force it to only go the preferrred way.

Also we dont want all 40 statiosn to be regenerating the golden packets.  Just the stations about every 7 hops or so.
In this respect, maybe we should designate the regenerating statiosn beforehand so that we can enforce it.

This way the packet can go the needed 40 to 50 hops, yet still maintain a record of the hops.  We will need to come up with 1and2-LETTER abbreviations for all peaks along the way, so that we can keep the final packet under 80 bytes!

Then we set aside a weekend and go do it!  We might need to schedule two weekends, one for the first attempt, and the second one for all of us that screw it up the first time...

If you are interested in gettting involved in the planning and activation of this, please join the peak2peak group on yahoo groups...  But we will distinguish this specific event as the AT Golden Packet event.  Anyone know of any high-PR dates for the AT that might  be appropriate?

Again, I only saw the tip of the iceberg today when I saw a note on SOTA, and I hope I am not jumping the gun and jumping into someone else's project.  But I sure get excited when it comes to playing PACKET.  And this is the ultimate... packet...

Need people with good RF and mountain top experience to help organize and plan out the HOPS.  I bet, on our own freq, we can probably even average 100 mile paths if we really do it right.  That would only take 20 hops...

I'll certainly volunteer to plan the Maryland hop...

Bob, Wb4APR



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