Re: [dstar_digital] Re: Limited access
On Jun 26, 2008, at 3:20 PM, nj902 wrote: Beg to differ, Nate. I know you computer gurus are all gaga about the world-wide call sign routed [Nextel Direct-Talk] D-Star model, but from the point of view of an Emergency Management Agency, we have no interest in having one of our communications resources tied to the entire planet during a local emergency. Hmm, how to respond to this to clear up misconceptions about what I'm saying... I'm not gaga about it, in fact I find it has serious flaws. Source- routing is great as long as there's always an ack system to prove you source-routed all the way to your destination. D-STAR has this (RPT vs UR back from the repeater) but it often disappears in practice, and I'm not sure why. The system could also benefit from real-time warnings about doubling (which would require a lot wider frequency split or a mobile duplexer built into the rig so you could listen at the same time as transmitting) etc. It's not perfect, by any means. But as I'm learning to say, It is what it is. A Gateway-equipped D-STAR system is instantly a fully- linked, source-routed system. If that's not what you wanted to use, why are you building a Gateway-equipped D-STAR system for your local use? It is what it is. Or another way to look at it, use the appropriate tool for the job. A local only net, probably shouldn't be on a D-STAR Gateway-equipped system, if there's some logical, serious concern, about interruptions from afar. We might be interested in regional networking or access from the State EOC - it depends on the circumstances. I understand completely. All I'm saying is that plenty of EmComm nets and activities happen on shared spectrum in both training (peacetime) and very trying times, and those Nets don't have the ability to block out other spectrum users. They have procedures and knowledge of how to adapt to an interloper, intentional or accidental. Actually, if D-Star really takes off, it is inevitable that there is no way everyone will play together and there will be separate networks, subnetworks, connect disconnect on demand, or whatever turns out to be the evolution of things. Perhaps. Right now it's bringing dissimilar groups together around the technology. And there ARE mechanisms built in to filter out things and/or people you don't want to hear, but not to force them not to timeshare on the repeater, really. Digital code squelch comes to mind here. The distinct user groups can agree to a code and only hear the other guys if they find/use the same code, press the EMR button and holler HELP or however that darn BK button works... I haven't quite figured that one out yet. Does anyone on an EmComm Net really need to run open squelch other than the Net Control? Food for thought. But... in order to take full advantage of that particular part of the technology, the participants need to pay attention to the displays on their rigs. Take that a step further. Do the participants in the event really need to hear each other? Could the Net Controller callsign route to everyone as needed? If folks go back to making sure they voice ID, could the radios be pre- programmed with RS1 RS2 MED1 MED2 for things like Rest Stop 1, Rest Stop 2, Medical 1, Medical 2, etc... and the Net controller's rig have all of those available as UR memories? Want to get less specific? RS for all Rest Stops. MED for all Medical. SAG for all Sag Wagons. Just to use one type of event as an example... a bike race. Change these as you see fit to match your needs. These are just rambling thoughts... your Net runs your way. That's how it goes. I'm just challenging folks to think about how to implement this new technology they've chosen. It will do a LOT of things, but few are pushing the envelope and trying them out as ways to make things better. But sticking to the old analog repeater ways is limiting, to some extent. Someone has to break ground and try some other methods. If they work well, great. If it sucks... call it a learning experience. Certainly real public safety dispatch has changed over the years. Trunking, Talk Groups, etc... all used regularly now. The Fire Chiefs may listen to all districts, but the grunts don't. Same with the police. And the garbage truck guys may be sharing the same repeater infrastructure too! New ideas don't automatically mean BETTER ideas. For proof just look at the glitzy, state-of-the-art, digital dashboard in the 84 Corvette. Others tried it too. Look into any car today - what do you see? Good old fashioned analog readouts. People found that the old model works best. Never said they did. Just saying instead of putting the load on the admin to try to tear down and reconnect a system at the whim of the users of the system, on a system that was never intended to be disconnected from the overall cooperative network,
Re: [dstar_digital] Re: Limited access
At 05:36 PM 6/27/2008, you wrote: I was told the that the Internet was still available in parts of New Orleans after Katrina eventhough the power and the telephones were out. Yes, that's what I heard as well (read my notes on the most common failure mode for Internet linked repeaters). http://www.renesys.com/tech/presentations/pdf/Renesys-Katrina-Report- 9sep2005.pdf I wonder how many internet users THINK the internet is out but its only because their cable modem went dark when the AC power quit at their location. A simple car battery and a $39 12 volt to 120 volt inverter from Wallmart would have solved that problem. Should part of every ham's emergency kit contain a way to operate their cable modem from battery power? Yes, my experience here is that cable Internet often does survive power outages, provided you have a means to power your equipment. My current cable modem could be run directly off 13.8V, so I could even ditch the inverter. :) I haven't bothered yet, because I haven't decided how best to manage the IRLP PC (which is also the router at that site), so there's no point keeping the cable modem up. The repeater will stay up though, as it has battery backup available. 73 de VK3JED http://vkradio.com
[dstar_digital] 23 cm yagi
Nice Home Brew plan here; http://vitsch.net/ham/homebrew/23cm_beam/ http://vitsch.net/ham/homebrew/23cm_beam/ [Non-text portions of this message have been removed]
Re: [dstar_digital] Re: Limited access
Thank you all for your responses. I now have a better perspective of things. Matt / N3WNX
Re: [dstar_digital] Re: Limited access
On Fri, 27 Jun 2008, Jack wrote: I was in Lafayette, LA for this event, our cable Internet was only as good as there batteries and gas powered generators, then there was also the lines that were down. The short COX had limited or no coverage for 3 days in some areas and in the rural area I lived in it was 9 days till the cable was restored. DSL around here seems to be the best bet. I've had 20 minutes of downtime since April 2001. -- ...DOUG KD4MOJ Tallahassee, FL
Re: Re: [dstar_digital] Re: Limited access
Tony and all, Here in Tampa Bay, Florida, area we have a number of cable providers that offer cable, internet, phone, etc. on one cable. I have Verizon FIOS which is a fiber optics to the home and I subscribe to cable TV, internet at 3 Mb and phone. The phone is high, but the others are competive with others. When home power is lost the only thing working is the phone and on a battery. The battery is good for about 4 hours. No cable TV or internet even though you might have gen/battery power for computer. Just the way it is done. For New Orleans after Katrina it would not be a good test to compare DSL or any other serice in normal operation as we all know. For a Katrina one can expect most all services to be down except the sat stuff like Direct TV or other sat services we now have with our EOCs. Unless you have this sat service you will probably be down. My Verizon I think is in Texas with some type of connection servers here. 73, ron, n9ee/r
Re: Re: [dstar_digital] Re: Inside Chassis coax - lossy
Mobile duplexers work very well. Repeaters have been built for years with the mobile duplexers inside the repeater enclosure with very good performance. If replacing the cables and moving outside I would think the cables were the problem and not where the duplexer was. Since you replaced the cables this is probably the solution and not the moving the duplexer outside. This tells me the repeater had poor cables to start with. 73, ron, n9ee/r From: Nate Duehr [EMAIL PROTECTED] Date: 2008/06/27 Fri AM 01:59:59 EDT To: dstar_digital@yahoogroups.com Subject: Re: [dstar_digital] Re: Inside Chassis coax - lossy On Jun 26, 2008, at 1:15 PM, Mike wrote: Also the UK 70cms module came with a ready pre-tuned duplexer that was mounted inside the case, as soon as we moved it outside of the case and fed it direct with decent coax the difference was unbelievable in sensitivity.
Re: RE: [dstar_digital] Re: Limited access
As stated access to the internet from your local connection will probably not be aviable if a Katrina or the like hits. The internet will be there, just the last mile will not. Some here with D-Star are thinking of RF linking to distant city DSTar repeaters for the gate way; a link or remote base using DStar rigs on the repeater. We provide the local repeaters with a link to another 100 miles away DStar repeater that has the gate way. No guarantee, there is never is, but some reasonable back up is needed. If one is really concerned do as most EOCs do, have the internet via a satelite connection. The EOCs have expensive systems with even portable flip up antennas on the emergency comm vehicles. As Hams we can do the same with something like Direct TV. Be prepared to do the install after the storm, not the one you are using now. 73, ron, n9ee/r From: Woodrick, Ed [EMAIL PROTECTED] Date: 2008/06/26 Thu PM 11:07:01 EDT To: dstar_digital@yahoogroups.com dstar_digital@yahoogroups.com Subject: RE: [dstar_digital] Re: Limited access Matt, Since its inception, the Internet has never gone down.
[dstar_digital] D-STAR Field Day Update
D-STAR Field Day Participants, With just over 24 hours before D-STAR Field Day begins, the excitement is growing. Everyone is thinking about what they need to pack. The generators have all had their oil changed and the games are about to begin. A suggestion for reflector use. From what I've seen, the C modules on the reflectors are where a number of repeaters are linked full time. To keep from bothering these folks, why don't we try to stay away from the C module. And we probably ought to stay off of the non-North American Reflectors. Suggested Reflector Usage REF001A Voice Simultaneous Data REF001B Data Only REF002A Voice Simultaneous Data REF002B Data Only REF004A Voice Simultaneous Data REF004B Data Only Simultaneous Data is those who are going for 3 point contacts, where they can type and talk at the same time. If you've misplaced the D-STAR Field Day Rules or Update, you can download them at www.DSTARINFO.comhttp://www.DSTARINFO.com, there's even some sample logs. Don't forget that D-STAR Field Day goes the entire 27 hour period, no matter when you start setup. Do some demonstrations before everyone else starts! Ed WA4YIH p.s. I'll be W4GR 7A GA and will probably hang around either of the REF002A or REF002B ports. Good Luck in the Contest! [Non-text portions of this message have been removed]
RE: [dstar_digital] ID-1 DD Mode
Hi Adrian, Would like to check the following; 10.0.0.1 Internet access. I'm not getting it? For what reasons would you expect there to be DD internet access in Australia? Cheers Richard VK3JFK
Re: [dstar_digital] D-STAR Field Day Update
Ed, DStar FD is a very good idea. It would do what FD is about...testing for emergency comm and show what DStar can do to the so many who have never seen DStar. I will try on our local DStar repeater that has the gate way. I am sure most QSOs will be via the gate way...a terrific way to demo its usefulness. 73, ron, n9ee/r Ron Wright, N9EE 727-376-6575 MICRO COMPUTER CONCEPTS Owner 146.64 repeater Tampa Bay, FL No tone, all are welcome.
[dstar_digital] Re: D-STAR Field Day Update
Is there an acceptable range of frequencies for simplex? [ED - Yes, don't use 146.52 (see the rules) and stay out of any repeater frequencies, satellite sub bands, cw/ssb segments ... other than that, have fun. In many areas 145.67 mHz. is the D-STAR contact frequency, I'd start there. In some areas there is little or no use of the bottom of 430 (91AD goes there, I would venture other D-STAR 70cm radios do as well.] --- In dstar_digital@yahoogroups.com, Woodrick, Ed [EMAIL PROTECTED] wrote: D-STAR Field Day Participants, With just over 24 hours before D-STAR Field Day begins, the excitement is growing. Everyone is thinking about what they need to pack. The generators have all had their oil changed and the games are about to begin. A suggestion for reflector use. From what I've seen, the C modules on the reflectors are where a number of repeaters are linked full time. To keep from bothering these folks, why don't we try to stay away from the C module. And we probably ought to stay off of the non- North American Reflectors. Suggested Reflector Usage REF001A Voice Simultaneous Data REF001B Data Only REF002A Voice Simultaneous Data REF002B Data Only REF004A Voice Simultaneous Data REF004B Data Only Simultaneous Data is those who are going for 3 point contacts, where they can type and talk at the same time. If you've misplaced the D-STAR Field Day Rules or Update, you can download them at www.DSTARINFO.comhttp://www.DSTARINFO.com, there's even some sample logs. Don't forget that D-STAR Field Day goes the entire 27 hour period, no matter when you start setup. Do some demonstrations before everyone else starts! Ed WA4YIH p.s. I'll be W4GR 7A GA and will probably hang around either of the REF002A or REF002B ports. Good Luck in the Contest! [Non-text portions of this message have been removed]
Re: [dstar_digital] Re: Limited access
And I was in the eye of a CAT5 hurricane and the internet, the electricity, the REPEATERS, the Cell towers and commercial towers were down. Even the hospital (Fletcher-Allen) had no electricity. The generator got whacked too. The EOC in Punta Gorda was out of service and the Sarasota EOC filled in until they got up and running 24 hours later. I recall having this conversation once before, Hams were heavily relied upon that week. There is a thing called line of sight! In other words, simplex operations or non repeater operation. Every excercise should be carried out as though these services are not there and then migrate those services back into the excercise. Start at the top of the emergency rather than at the bottom. But what do I know So it does happen... 2004 Hurricane Chalie, Punta Gorda, Port Charlotte Florida. de N1TAI -Original Message- From: Woodrick, Ed [EMAIL PROTECTED] To: dstar_digital@yahoogroups.com dstar_digital@yahoogroups.com Sent: Fri, 27 Jun 2008 10:19 am Subject: RE: RE: [dstar_digital] Re: Limited access I have walked into a location where the eye of a hurricane has passed and Internet was available. And don’t forget that we seldom locate repeaters in valleys that are prone to flooding, I like my repeaters on top of the hill. Not all repeaters are connected with DSL service, some have very high reliability connections. No, I’m not going to count on the fact that Internet is going to always be available. But I’m not going to say that it never will be available. History has shown that the Internet is much more survivable than some hams think. [Non-text portions of this message have been removed]
Re: [dstar_digital] Re: D-STAR Field Day Update
This is really cool... FD on the internet -Original Message- From: txhemi57 [EMAIL PROTECTED] To: dstar_digital@yahoogroups.com Sent: Fri, 27 Jun 2008 11:56 am Subject: [dstar_digital] Re: D-STAR Field Day Update Is there an acceptable range of frequencies for simplex? [ED - Yes, don't use 146.52 (see the rules) and stay out of any repeater frequencies, satellite sub bands, cw/ssb segments ... other than that, have fun. In many areas 145.67 mHz. is the D-STAR contact frequency, I'd start there. In some areas there is little or no use of the bottom of 430 (91AD goes there, I would venture other D-STAR 70cm radios do as well.] --- In dstar_digital@yahoogroups.com, Woodrick, Ed [EMAIL PROTECTED] wrote: D-STAR Field Day Participants, With just over 24 hours before D-STAR Field Day begins, the excitement is growing. Everyone is thinking about what they need to pack. The generators have all had their oil changed and the games are about to begin. A suggestion for reflector use. From what I've seen, the C modules on the reflectors are where a number of repeaters are linked full time. To keep from bothering these folks, why don't we try to stay away from the C module. And we probably ought to stay off of the non- North American Reflectors. Suggested Reflector Usage REF001A Voice Simultaneous Data REF001B Data Only REF002A Voice Simultaneous Data REF002B Data Only REF004A Voice Simultaneous Data REF004B Data Only Simultaneous Data is those who are going for 3 point contacts, where they can type and talk at the same time. If you've misplaced the D-STAR Field Day Rules or Update, you can download them at www.DSTARINFO.comhttp://www.DSTARINFO.com, there's even some sample logs. Don't forget that D-STAR Field Day goes the entire 27 hour period, no matter when you start setup. Do some demonstrations before everyone else starts! Ed WA4YIH p.s. I'll be W4GR 7A GA and will probably hang around either of the REF002A or REF002B ports. Good Luck in the Contest! [Non-text portions of this message have been removed] [Non-text portions of this message have been removed]
[dstar_digital] Re: Inside Chassis coax - lossy
That's a pretty broad statement that needs a qualifier... they work well in the proper application. Most UHF mobile duplexers, are just simple notch types that will offer you some isolation from your own transmitter, but not from anything or anyone else. Even then, you only get about 65dB of isolation... so you better be using low power. They work well for portable repeaters and duplex subscriber units... real repeaters use real duplexers. Lee
Re: [dstar_digital] Re: Inside Chassis coax - lossy
Lee: Sorry, but just because I'm feeling contrary today I have to ask. Didn't we just have a discussion about how you don't need to run much power for a repeater? Most of the mobile duplexers are fine for 25-50 Watts. I have one repeater that runs 15 W out with about 7 at the antenna and it covers out to some 60 miles for mobiles. It's a real repeater--I think. Chuck - N8DNX ve7fet wrote: That's a pretty broad statement that needs a qualifier... they work well in the proper application. Most UHF mobile duplexers, are just simple notch types that will offer you some isolation from your own transmitter, but not from anything or anyone else. Even then, you only get about 65dB of isolation... so you better be using low power. They work well for portable repeaters and duplex subscriber units... real repeaters use real duplexers. Lee
Re: Re: [dstar_digital] Re: Limited access
Not sure what Cat 5 hurricane you were in. There has never been a Cat 5 hurricane hit Florida going back over 100 years. Sure there has been one, maybe within last 100,000 yrs, hi. Kertina was Cat 5, but down to Cat 4 before hitting New Orlenes. I remember Charley in 2004. Was headed right up the west coast headed right for us in Tampa area. A few of my friends went to Orlando to wait it out. Got to about Sarasota and made right turn and followed my friends to Orlando. They spent the next week operating a chain saw, 73, ron, n9ee/r
RE: Re: [dstar_digital] Re: D-STAR Field Day Update
Ron, The rules do not specify the access, so DVDongles are fair game. There are basically three types of contacts, Voice, Low Speed Data, and High Speed Data. Since D-STAR can do voice and data at the same time, then you can actually get a Voice and Low Speed Data Contact at the same time. The rules and updates are at www.DSTARINFO.comhttp://www.DSTARINFO.com D-STAR Field Day is not ARRL Field Day, the rules are different (which is why there are two activities). D-STAR Field Day follows the intent of ARRL Field Day in that practice and demonstration are the goal of the activity. In the D-STAR Field Day Update document, the following were listed as things to try: · Voice Contact with source routing, no linking · Voice Contact with multi-cast (See local administrators to determine if possible) · Voice Contact with two linked repeaters · Voice Contact through Reflector · All of the above with a Data contact at the same time · Low speed Data contacts · High Speed Data Contacts · High Speed Internet Access · DVDongle Contacts From my point of view, it’s a weekend to do a little playing with D-STAR. There should be a number of people on the bands and a lot of activity. If you work hard at playing, you might even get a plaque. From: dstar_digital@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Ron Wright Sent: Friday, June 27, 2008 2:05 PM To: dstar_digital@yahoogroups.com Subject: Re: Re: [dstar_digital] Re: D-STAR Field Day Update Have not read the DStar FD rules, but do DV Dungle?, computer to repeater to user contacts count for points??? If testing for emergency comm would think so for this mode would be used in disaster just like Echolink and IRLP have been used in some disasters here. It has been found Echolink is very useful as I am sure IRLP. Might consider DV Dungle to DV Dungle also. This could lead to a whole new EmComm feature. 73, ron, n9ee/r ps I think I got DV Dungle spelled wrong, sorry. [Non-text portions of this message have been removed]
Re: [dstar_digital] ID-1 DD Mode
Thanks for the answer, That's what I thought and expected. 23cm DD module sysop setup etc. My setup was correct. I have mobile internet anyhow We can play intranet etc. On to the next project now. vk4tux - Original Message - From: Richard Hoskin To: dstar_digital@yahoogroups.com Sent: Friday, June 27, 2008 11:54 PM Subject: RE: [dstar_digital] ID-1 DD Mode Hi Adrian, Would like to check the following; 10.0.0.1 Internet access. I'm not getting it? For what reasons would you expect there to be DD internet access in Australia? Cheers Richard VK3JFK [Non-text portions of this message have been removed]
Re: [dstar_digital] DPRS
The Delorme EarthMate USB can output NMEA. Here is a site that shows the USB Earthmate supporting NMEA-0183. http://www.byonics.com/gst-1/ Charles Miller [EMAIL PROTECTED] wrote: Gus, Don't d-star radios require NMEA.� I don't believe that Delorme is NMEA. 73 Charlie AE4UX
[dstar_digital] D-Starlet and D-Rats Repeater
I have also tried D-Starlet with D-Rats repeater proxy via Serial Port Redirector prog successfully. Anyone who uses D-Starlet and would like to test via the net please email me (good on qrz.com) vk4tux at bigpond.com vk4tux
[dstar_digital] Re: Inside Chassis coax - lossy
Hah, lets not go down that rat hole again. ;) I wasn't referring to the power handling capability of the mobile duplexers, as I was more trying to make the point of how broad their pass is. With an easily overloaded RX (think a mobile masquerading as a repeater receiver... ala D-STAR and others), in a typical high RF repeater site, a mobile duplexer is inviting trouble. I have a bunch of old Harris radios, with said mobile duplexers built in, and they work great in our high-speed packet backbone, with links using between 5 and 30W. BUT, they also have a manually tuned pre-selector on the front end to keep all the junk out. Cheers! Lee --- In dstar_digital@yahoogroups.com, Charles Scott [EMAIL PROTECTED] wrote: Lee: Sorry, but just because I'm feeling contrary today I have to ask. Didn't we just have a discussion about how you don't need to run much power for a repeater? Most of the mobile duplexers are fine for 25-50 Watts. I have one repeater that runs 15 W out with about 7 at the antenna and it covers out to some 60 miles for mobiles. It's a real repeater--I think. Chuck - N8DNX
RE: [dstar_digital] Re: Limited access
Ed WA4YIH wrote: Since its inception, the Internet has never gone down. There are places where access has been unavailable, but the Internet has never gone down. Except for the last mile, most Internet connections are highly redundant. In the middle of Katrina, in the middle of the biggest California Earthquakes, the Internet has been available. (snip) Well worked, Ed. As we're building out a few D-STAR systems ... we're making sure that they are designed to be as reliable as possible - including the gateways and network connection. In what I've drawn up so far - one of the weakest points in our whole configuration is the D-STAR repeater controller itself! Its easy to configure redundancy in that last mile network connection ... and setup a reliable gateway including maybe even a backup system. We can sustain the failure of a band module - which would leave other modules available. But if we lose the controller itself ... ugh! (Sorry if this thread is getting a bit off-topic ...) Bob W1QA [Assistant Moderator - This is on topic.]
Re: [dstar_digital] Re: Inside Chassis coax - lossy
Charles Scott wrote: Not exactly the kind of comments I'd expect from you. I didn't notice which band it was for this unit, but from 440 up the little mobile duplexers can be pretty small and work well for low-power applications. Also, why are you worried about shielding? I believe the radios in the repeater chassis have their own shielding, and what leakage would you expect from one of the small mobile duplexers? Considering the possible problems that have been reported with the jumpers inside the case, it may have been an improvement! Sorry, was in a horribly bad mood last night. Big escalated issue at work. Still going on, but now we're down to Nate will work all weekend to make sure the problem is fixed. instead of conference calls with angry C-Level execs. (I wouldn't mind so much if I hadn't audited these configurations and then someone copied the wrong one to all of the production systems instead. Sigh. 40,000 phone lines worth of teleconferencing equipment misbehaving all over the country is not a good way to spend three days, in case anyone's thinking about a career in telecom technical support. It's also a great way to miss participating in Field Day, for the most part. Sigh. Oh well, I'll get a bunch of OT, and maybe that'll pay for an ID-1. GRIN! There's always a silver lining, right? Heh heh.) I shouldn't have hit send on that one. But since we're here, I'll be nicer... and explain better... Don't know what you have against the smaller mobile duplexers, but I've used them in a number of applications and they work just fine--good rejection (for these power levels), not much more loss that a full sized duplexer, and certainly no leakage. They just don't handle much power. Real shielding using grounding strips, etc... between sections is what a real repeater (GE) has. Or individual RF shielded boxes for each section if they're on the same board (Moto). These mobile in a box repeaters are problematic at high RF (commercial) sites. They're okay but it sure would be nice if Icom would spend an additional $100 on sheet metal work to block the two sides from each other. As far as the mobile duplexer... I guess they're okay, I just don't build with them. 1/4 wave on UHF just isn't that physically big, and fits fine in most cabinets. VHF, is a pain, and most mobile duplexers won't handle our 600 KHz typical (now California is doing 400 KHz) splits very well. Sorry, Nate, just don't see a real problem with this on the surface as long as it was physically well done. Understand. It's just MUCH easier to over-do-it a bit on the duplexer and cabling, etc. Plus... all these reports that cruddy cabling may have been used internally really chaps me badly for a box that costs $2000 or more U.S. -- these things should be brick you-know-what-houses for that price. How much margin in Costs of Goods Sold (COGS) is there, in packaging two $500 mobiles in a metal box? A lot. Not including RD, there's probably at least $1000 profit in these boxes. (Because the mobiles don't cost Icom $500/ea to put in there, anyway.) I very much looking forward to seeing the rumored other repeaters that people are working on. Keeping one of these things alive on a high-mountain site complete with trips to investigate problems is a $100 round-trip issue every time it happens at today's fuel costs. While this might argue that it's a good idea to replace these cables, etc... now... when it's cheap... it bugs me to no end that Icom isn't just upgrading them in later versions of the repeater. Adding proper TX to RX shielding (a metal wall between the two rigs with fingerstock on top, as a bare minimum?) etc, is too easy to ignore. It's a bolt-in fix that can't cost more than $15/repeater, including development costs to pay an engineer to draw it on a CAD program. Others will eventually fill the void Icom has in their repeater engineering skill-set... I was just grumpy that someone stuffed a mobile duplexer inside too... in a box that already has reported leakage, and other problems. Think RF can't get through that 4 hole where the fan is, for example? That's not shielded. The repeater RF packaging is a joke. It'll get better. Either Icom will step up, or someone will knock them off the perch, but it'll get better... I'll hold out hope for that, anyway. Nate WY0X
Building redundant D-STAR Systems (was: Re: [dstar_digital] Re: Limited access)
Bob McCormick W1QA wrote: In what I've drawn up so far - one of the weakest points in our whole configuration is the D-STAR repeater controller itself! Its easy to configure redundancy in that last mile network connection ... and setup a reliable gateway including maybe even a backup system. We can sustain the failure of a band module - which would leave other modules available. But if we lose the controller itself ... ugh! Bob, this is actually a very interesting topic. One thing I've heard some groups have done is bypass that power bus topology of the controller altogether. It really does nothing more than turn power distribution into a single-point-of-failure. Plugging the modules into power directly would not (as far as I can tell) suffer any ill effects, unless they were accidentally hooked to floating grounds that didn't tie together. That could make the serial protocol between the controller and the modules unhappy if current were flowing. The brains of the controller is harder. One could buy two of them and build a complex switching system for the four module cables and the Ethernet... but that device probably introduces more possible points of failure than the controller itself does. Hmm... interesting topic. There's also been some discussion about how to harden the Gateway server properly, but those are generally well-known best-practices that any server admin who understands Linux could accomplish pretty easily. Same with the network gear, kinda... at least there's some commercial class networking gear that could be pressed into service and probably never show a fault in many years of operating time. Even some semi-commercial quality gear will do that nowadays. What else would need to be considered? Obviously a power source... automatic generator, if really paranoid a battery plant (and figure out some way to alert over D-STAR itself that the battery is online and site power is off... h... another side project...), etc. Nate WY0X
[dstar_digital] Re: Inside Chassis coax - lossy
Yes, we tuned a Celwave 6 can mobile UHF duplexer to 100 db using an IFR and and a return loss bridge. It's the best one I've seen, as most are in the 75 to 85 db range. When Telewave recently retuned our 6 can full sized 2 meter duplexer for our new 400 kHz split, they were happy to hear that it was a digital system and the deepest and narrowest notches could be used to achieve maximum notch. Ernie W6KAP
