Mykle: Thanks for your comments and your interesting case study on the problems of hidden terminals and APRS. Its encouraging to see there are still a few people that understand the basics of packet radio and how to properly concieve an RF data system. You can call it what you want (BBS, NOS, APRS, etc. etc.) but if you ignore the common layer 1 and 2 issues, you'll end up with a poorly performing system irregardless of the application layer as you found out. Hopefully some of the Linux types can get involved and put real (RF) networking hooks into a APRS like clone. I'll do what I can. -Jeff Mykle Raymond wrote: > Hello Jeff, > > A couple of postings to APRS-HAMS were forwarded to me by Bob W6SWE, > particularly > comments added by you and then by Steve Dimse. > > Keep it up! > > I still run a 145.01 simplex node on top of the hill north of Tucson (a > mile HAAT). Minimal bbs traffic these days, but mailbox connections here > and yon, connections thru gates for chatting or exploration, and so on. A > few people are still having some fun. > > I'll pull the plug when we can replace it with something else, like > connecting the voice repeater that is dedicated to packet (gotta fix it > first). We'll link thru microwave (almost in place for a linked repeater > system) and/or thru a regenerator dedicated for link use. I've long been > tired of needing a bulldozer station to connect to the node, when I'm used > to exploring far and wide with an HT on the packet repeater. > > We've just installed an APRS digi at the same place, "for testing". My > home station on the same old HT was working nicely thru the local low level > digi. Not any more. Looks like it takes 10 to 20w minimum to get thru all > the traffic that the hi digi is seeing. (hidden stations in spades) > > It's looking to me like we have several purposes for APRS that are > separating from just one. One is a collection of fixed stations (home, red > cross, wx, digi) and mobile users with significant watts. > > Second is QRP stations, like hikers (I've been a Search and Rescue > volunteer for years), runners, bicyclers, and other stations that won't be > running double-digit watts. > > Sure, it was fun last night watching a local ham return from a trip for > three hours, from the west side of Arizona into Phoenix and home to Tucson. > All from my HT at home (but you sure weren't going to be seeing MY > station!). If wide-area coverage of stations with watts to spare is what > interests you, then fine. > > A second frequency for the less-well-endowed appears to be required. Maybe > I'll welcome them to the packet repeater and save a few digi's. > > As you pointed out, we're ignoring the issue, and using lots of band-aids. > APRS on one frequency serves some but not all of the present users. As the > number of users increase, the one-frequency system will serve a smaller and > smaller proportion of APRS users. > > It is really surprising that one frequency has been adopted > coast-to-coast-to-coast (east, west, and north). Congratulations to all > that worked hard on that issue. It serves most of the APRS users at > present, but not for long. > > This very high Tucson digi may remain in place. It does appear to serve a > limited purpose. As the large boxes presently needed for radio, tnc, gps, and > power become smaller boxes, I may eventually be able to throw one into my > already overloaded backpack. It won't be on 144.39, not the way it > presently works! > > We'll be watching for other methods for making this work, such as those you > have mentioned. Simplex is simple, but not for a large number of users. > APRS is another flavor of packet, with advantages of it's own, but it is > still packet. > > Keep preaching, there will be a few who understand. > > The Hidden Station > Mykle N7JZT > > ZONGE ENGINEERING FAX: (520) 325-1588 > 3322 East Fort Lowell Road Voice: (520) 327-5501 > Tucson, Arizona 85716 E-Mail: [EMAIL PROTECTED]
