On Sep 4, 2007, at 1:51 AM, Steve S. Bosshard (NU5D) wrote: > "The full "D-Star stack" of VHF, UHF, and 1.2 GHz all at the same > physical SITE is a waste of spectrum, and should be avoided also. > > Nate Duehr" > > There are around 14 DSTAR users in Temple, Texas, and our neighbors in > Waco and Austin are moving forward with their own systems as well. > The > 'full stack' may indeed be a waste of spectrum unless there is a need > for more capacity. I am finding the 1253.0000 digital HS data > repeater > is unique to the system - no voice just 128kb/sec data. Thus far we > have not set up a network between stations, just tested the internet > connection and it does work at around 80kb/sec. (3 of the 14 have 1.2 > capability and the number will grow). Also the coverage at 1296 is > not > bad (different than 2M or 440, but not bad).
Understood. My understanding of the 128Kb/s data "repeater" is that it's a store-and-forward system similar to Packet, and is not full- duplex. The photos you provided (or someone did?) on the other list seemed to back that understand up in that there's a single mobile rig inside the 1.2 GHz HS "repeater" box. So... I don't lump that box in with the repeaters that Icom has out for D-Star... it's more like a very high speed proprietary Packet mode, to me anyway. Would you agree? > There are many times when a user wants a local chat on 2m/440 (not > necessarily both) and there are times someone wants to use the gateway > to make an out of area contact. Having 1292.1000 digital voice plus > either 2M (very crowded most places) or 440 (not as crowded here in > the > sticks) while not a full stack, does have a place, and 1.2 G is pretty > much under utilized most places. Propagation on 1.2 Ghz makes > frequency > re-use less of a challenge. Add to this an occasional traveler > through > the area, and with the Belton Hamfest bringing several thousand > hams to > the Temple/Belton area a couple of times a year, I can see how a > single > repeater might be less than ideal. That makes a good case for TWO repeaters, but not the whole "stack". :-) I could see a VHF/UHF pair of repeaters, or a VHF/1.2, UHF/1.2 or best, a UHF/1.2 -- but all three at the same site? Three seems a bit overkill strictly from a spectrum-use standpoint. At least where things are today with VHF essentially "full" in many metropolitan areas. > Having DSTAR Chat run concurrent 1.2kb/sec low speed keyboard chat > with > digital voice at the same time on any of the digital voice > repeaters is > also a nice added feature that better utilizes spectrum. (You cannot > have separate voice and data transmissions - low speed data rides with > voice whether you use it or not) Add to this the 6.25 Khz > bandwidth for > still better spectrum utilization. I cannot see using a 20 Khz > channel > in 2M plus a 20 Khz channel in 440 to duplicate efforts unless > there is > a real demand, but I can see 23 Cents added to either a 440 or 2M > system > to offer some unique features. Seems like the 23 cent HS data > repeater > is a simplex operation that is around 200 Khz wide and could not > pratically be used in the lower bands. Yeah, we basically agree here then. And you confirmed my thoughts about the "simplex" nature of the 1.2 HS data system. > I believe coordinators should offer incentives to more spectrally > efficient technologies such as P25 and DSTAR. This will ultimately > open > more spectrum over time, and while I agree both P25 and DSTAR are > repeaters, rule changes to foster more spectrally efficient > technologies > may be indeed appropriate, especially when dead repeaters block the > use > of channels that would otherwise be used. There's been some discussion here locally about that "incentive" part. What exactly is the incentive that would drive someone that has a perfectly working VHF system to dumpster it and put up a VHF D- Star system? I think it's going to be a hard-sell to some organizations. An example might be my club's particular setup. We have three VHF systems spread out over 150+ miles, linked. Then we have one higher standalone VHF system. There's no clamor from the end users for anything D-Star related right now, and most new hams and/or financially challenged hams buy single-band VHF gear. I think if we took a poll today, we'd be surprised how many of our club members ONLY have VHF radios. We also have four UHF systems and the likelihood that one of those might be "re-purposed" for something digital down the road, is far more likely than reconfiguration of the VHF setup. Right or wrong, but mostly due to the manufacturer's marketing techniques of selling VHF rigs at or below cost, VHF tends to be the "lingua franca" of repeater afficionados... everyone has a VHF rig. Most (but not all) have UHF, and only a handful in this area have shown any interest at all in D-Star, yet. So with that in mind... how could a coordination body offer us anything that would make us believe we just "had to" say, turn down that high-mountain VHF standalone and re-task it. I don't think there's anything they could offer that would "encourage" us, especially considering that most days, the standalone VHF repeater is in "lock-to-talk" mode from the beginning of drive-time until the end, at both ends of the workday. The three-repeater system is more about "coverage" and "features" and has an autopatch (lightly used, but used), IRLP node, and tends to be a local gathering place for Nets... every weeknight but one, and three Nets on weekends, for various groups/organizations. Depending on time of year and interest, that system serves something like 8-10 Nets, including our own. > It does seem (while the new hasn't worn off yet) there is a surge of > activity on DSTAR repeaters while many other repeaters lay virtually > dead. Time and the market will tell. Maybe that's our "problem". The only "dead" repeaters in our system right now is a UHF that is a stand-alone at one of the "end" sites for the linked VHF system, and another UHF we're using right now as a "tech"/testing system that's sharing an antenna with the more user- oriented UHF at anothersite. Everything else may not be busy 24/7, but each has a group of regular users who do use them -- taking any one of those away would mean upsetting someone's apple cart. Even the 6m machine which is plagued by TVI from close-by TV broadcast stations has a regular Net on it. Okay that's not 100% honest... the 1.2 GHz analog machine is pretty dead. Or so I hear. I have to borrow a radio to even work it. :-) How's that for sad? It's probably a candidate for replacement with something, and with P25 1.2 GHz radios not exactly being available -- a D-Star machine might be interesting. Problem is, I'm fanatical about our repeaters and would find it hard to justify a $1000 rig to work one system! I could justify the dual-bander V/U radio with the D-Star module installed, perhaps... at least it would have other purposes. We'll probably re-visit the 1.2 GHz machine's future sometime "soon" (with "soon" being measured in months, but probably not years), so there's a possibility for something digital there... Putting new things up is difficult, due to tower loading at one site, the two "end" sites being so far away from the Denver metro area as to not be that useful for the majority of our membership, and the high site being bloody expensive to add antennas to. I can't see any level of "incentive" short of buying the system for us or offering it at such a reduced price that we'd be fools to say "no" to it, that would get our club to bite/chew on D-Star on VHF... not yet, anyway... I'll always allow for hope. We could also be easily swayed to partner up with other organizations to do a "shared" project of some sort, but there's the resulting "which site should it go on?" and "who really owns it?" and "who's insuring it?" types of questions that type of project leads to, will make us think twice before stepping off that gangplank. I saw your other comments about being the "benevolent dictator" -- and I agree. If one has the funds and wishes to play, that's great. I don't. That's how I got involved in working on club systems to start with, and then by dumb luck (I showed up for the meeting) ending up a club President. (GRIN) There's folks out here that do that, not on D-Star around here (yet) but I'm sure it's coming. P25 is already here under the "benevolent dictatorship" one ham has on his system, but in a larger club, there's a stewardship issue: I shouldn't spend the majority of the annual captial expenditure budget on 1%-5% of the membership. But if there's enough interest, a special funding drive for D-Star (or anything else) is always a good way to get the ball rolling. We've done that before. Our organization has also never shyed away from trying new things, even if expensive, if a "reasonable" number of members might ultimately benefit. Thus, I could see a D-Star or other digital UHF system in our future... but that $1000 user-radio price tag for a rig that can do nothing but D-Star, keeps me away from 1.2 GHz... at least for the moment. I really lament two things in Icom's implementations -- one is that the 1.2 GHz repeater isn't dual-mode. (Well actually ANY of them, for that matter.) While I understand the reasons why not, it would have made an easier "transition process" for everyone, and the uptake of the technology would have been exponentially faster. If I could buy a dual-mode analog/D-Star repeater today, it'd probably already be on the hill, in some fashion or another, one band or another. Keeping existing "service" while offering something new, is something I could "pitch" easier to members, than blowing a few grand on a system only a few will be able to buy radios for. The other is that with 220 MHz not being legal for use in Japan, that we'll probably never see a D-Star repeater on that band. It'd be a shot in the arm for 220, and would really give existing system operators a way to expand at certain sites easily, without affecting "service" for their VHF/UHF systems. Like the dual-mode thing, if there were a 220 MHz D-Star (or any other digital mode) repeater available, if the club hadn't put it up by now, I would have... somewhere. Even if the silly thing was in my backyard. It'd hurt financially, but supporting 220 MHz in any way, seems to do that anyway. I have a nice Sinclair duplexer here (finally) after shopping for a long time for it, that will end up on a MASTR II 220 conversion, eventually... that project was going great guns until a multitude of other personal and club things got in the way, but it'll get started up again... especially when the snow flies and I can't get to the repeater sites anyway... and the ham shack will be put back together by then, too. The general lack of 220 MHz systems anywhere other than California, and a lack of multi-band user radios that include that great band, is a serious bummer, considering how well that band works... all the benefits of both VHF/UHF with little of the negatives of either, and a much lower noise floor in most metro areas to boot. It would be a sweet place in the spectrum to build a digital repeater network. (Spent the entire holiday weekend painting the newly remodeled basement/ham shack, nothing fancy -- it was time for the vinyl fake- walnut paneling and the brown almost-shag carpet to bid farewell! -- and I think it would have been easier to just sell the house. Ha! If it comes down to "Buy an ID-1" versus finishing painting the rest of the house, replacing all the wall outlets and switches, tearing down wallpaper in two more rooms, and generally keeping the other ham in the house -- my wife -- happy, I think the home improvement projects will win out. Heh. Wouldn't mind having that tower up that's been stored next to the garage for four years now, either... sigh... always something....) Oh, and oddly -- after all that work this weekend... I can't sleep tonight either! (GRIN) Good to hash out some thoughts on repeaters and the "future of ham radio" with you, though... G'night Steve... here's hoping that medication they have you on doesn't make you read this reply too early in the morning! -- Nate Duehr, WY0X [EMAIL PROTECTED]
