On Wed, 27 Jun 2007, Tom Russo wrote: > A portable digipeater-in-a-box, however, can be deployed at a mission as > needed --- it needn't be man-portable, can be in a rugged waterproof > container, and with a mast, big battery, and beefy mobile rig could be > very effective. Our SAR Support team has one and can deploy it as needed > (which in our case isn't often).
*) Steel ammo-can. *) Large gell-cell. *) Mobile antenna mounted to the lid, perhaps a 1/2 wave antenna so that it doesn't require a ground plane. *) 2-meter handheld radio. *) Kantronics KPC-3+ TNC, set up to digipeat. *) Perhaps a chain to lock it to a tree in case a stray hiker finds it during the mission. One problem with this setup is that you have to allocate a resource to put it into place and another to retrieve it after the mission. Perhaps someone to replace the battery during a longer mission. > I am still of the opinion that the SARn-N idea could work, but has the > potential to jam up a channel quickly as every field team digipeats every > other team's data. I am waiting to be proven wrong, at which point I'll > gleefully eat my words. At this point I have no way of doinng the > experiment myself, as none of the readily available tracker units can do > it anyway. I figure 10-15 teams in the woods, transmitting roughly every 3-5 minutes, with some of them being in range of others and some not at any given time, won't be that much of a load. At least with the WIDEn-N anti-duping algorithm and using the preemptive digipeating, it should work well. Yea, needs to be proven in real experiments. If I get my three T2's on the air I'll try it on another frequency and bump up the rate quite a bit to try to figure out what the practical limits are. Can also get other people with regular APRS non-digipeating stations on the same frequency for the experiment. There are other T2's in the area as well, a few T2-135's in Alinco's, and at least one other OT2M up in Canada (which is part of our backyard). Maybe we can get together for a combined experiment at some point. -- Curt, WE7U. APRS Client Comparisons: http://www.eskimo.com/~archer "Lotto: A tax on people who are bad at math." -- unknown "Windows: Microsoft's tax on computer illiterates." -- WE7U "The world DOES revolve around me: I picked the coordinate system!" _______________________________________________ Xastir mailing list Xastir@xastir.org http://lists.xastir.org/cgi-bin/mailman/listinfo/xastir
