Re: [Repeater-Builder] Possible to purchase IRLP node numbers for AllStar nodes to thus enable IRLP connections on AllStar system?
On Wed, 8 Sep 2010, Kent Johnson wrote: Bcc to 2010 VoIP Conference List -Original Message- From: David Cameron (IRLP) [mailto:dcame...@irlp.net] Sent: Wednesday, September 08, 2010 7:56 AM To: Kent Johnson Subject: Re: Possible to purchase IRLP node numbers for AllStar Kent, the short answer is no. I have had far too many complaints about people being brought into full duplex telephone calls and non-radio endpoints due to Allstar nodes on IRLP. The philosophy of IRLP is to keep radios on all ends of a link. Dave Cameron VE7LTD I call BS. -- Kris Kirby, KE4AHR Disinformation Analyst
RE: [Repeater-Builder] Re: Circular polarization for VHF repeaters?
On Fri, 3 Sep 2010, Mark wrote: Once you get it figured out, PLEASE write up an article for Repeater-Builder for the rest of us!! Make an X with dipole elements, and connect the feed harness to one side, and connect the left and right sides together with 1/4-wavelength of coax, wire, or coat-hanger. The antenna elements should be on opposite sides of the mast. Something about this tells me that the stack should have the next section up rotated 90-degrees around vertical to eliminate nulls. If you take that and try to build it all around the same point, it starts looking like an imploded Lindenblad. -- Kris Kirby, KE4AHR Disinformation Analyst
RE: [Repeater-Builder] Re: Circular polarization for VHF repeaters?
On Fri, 3 Sep 2010, Kris Kirby wrote: Once you get it figured out, PLEASE write up an article for Repeater-Builder for the rest of us!! Make an X with dipole elements, and connect the feed harness to one side, and connect the left and right sides together with 1/4-wavelength of coax, wire, or coat-hanger. The antenna elements should be on opposite sides of the mast. Something about this tells me that the stack should have the next section up rotated 90-degrees around vertical to eliminate nulls. If you take that and try to build it all around the same point, it starts looking like an imploded Lindenblad. I could go further to say that it should be possible to do this with two DB-224 clones, the ones that hold the elements to the pipes with hose-clamps. Connect up all the feed harnesses as you normally would and connect the two by a -90 degree hybrid, or a 0-degree (in-phase) Wilkinson divider with a -90 degree section (1/4-wavelength) of coax on one leg, so that one antenna is fed -90 degrees (1/4-wavelength) from the other. Pasternak's article makes mention that these antennas are difficult to match. Things being as critical as they are, I would recommend tuning for minimum VSWR, since the receivers are hardly ever 50-ohms. This antenna may lend itself better to a split-antenna system without much separation between the circular antenna and the vertical antenna -- simply to avoid detuning the receiver duplexers if the antenna loading situation changes due to ice or other effects. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Re: Circular polarization for VHF repeaters?
On Thu, 2 Sep 2010, Gordon Cooper wrote: I guess that I do not have much to contribute on this thread but to me it is very interesting reading. Gary has my sympathy, his problem is duplicated here. Much of my repeater work relates to a low power portable repeater on 141 MHz. We live near a medium sized mountain range which has plenty of deer and wild pigs. Hunters go looking for them and perhaps get lost, or fall and break a leg. Also, there are recreational trampers who just get lost . Several times a year we have to go find, and rescue them. The last time was two days ago at 6.30 am. For once, it was not raining! Our repeater runs 5 watts output, needs to run three or four days off a gelcell, and most importantly has to fit into a backpack to be carried to a convenient hilltop. Fortunately, the split is 3 MHz so that the duplexer is of a reasonable size. You need lower power output and a further split and a big battery. Even running a repeater at five watts with commercial handhelds out in the field (each of which have a battery that will make it for eight hours), you're going to need somewhere around a 33Ah battery, which weighs 25 lbs. The problem is getting reasonable coverage. Sure the search areas are fairly small but usually encompass several ridges and deep valleys. We use vertical polarisation with a 5/8 whip on the repeater and the search teams have flexible dipoles that fit into their backpacks. Sharp ridges and steep slopes contribute to coverage problems. Would circular polarization help?? I think not. Remember, a quarter-wave has significant energy in the pattern from about five degrees to eighty-five degrees; if you're dealing with valleys, this may be a better choice for an antenna. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Re: Circular polarization for VHF repeaters?
On Thu, 2 Sep 2010, Paul Plack wrote: Gordon, something worth trying might be low-band. About 20 years ago, I lived in an area where hams did course communications for rally events in very mountainous terrain. I remember experimenting one night about 2am with my partner at the other end of a heavily wooded course, about 12 miles end-to-end. 444 MHz simplex, 5 watts, colinear mobile whip - no copy. 146 MHz simplex, 5 watts, 5/8-wave mobile whip - no copy, but would barely break the carrier squelch. 29.6 MHz simplex, 4 watts, FM CB conversion, 1.3m helically-wound mobile whip - full quieting and S9+. Motorola Syntor Xs are relatively easy to locate, and can be programmed for 10m to 6m without any retuning. They were designed for 30-50MHz. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Re: Circular polarization for VHF repeaters?
On Fri, 3 Sep 2010, Gary - K7EK wrote: Thanks to all that replied. I appreciate your input. I'm still looking for answers, but may be onto something. I have emailed Bill Pasternak, the author of that Cushcraft 4-pole conversion article. I re-read his original article and may have figured out what I must do. That, plus any additional input from Bill, should hopefully help me to complete the project. I will post again later if I have any success. Best regards, Gary, K7EK Personal Web Page: www.k7ek.net If you find a copy out on the 'net, please forward me a copy of the link. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Circular polarization for VHF repeaters?
On Thu, 2 Sep 2010, Gary - K7EK wrote: In the 80's there was a amateur radio repeater book by a fellow, Pasternak I believe, that took two gamma match style Cuschcraft Four Pole antennas, combined them, and did some magic with phasing lines to end up with a four bay circularly polarized repeater antenna. Unfortunately the description leaves much to be desired, at least for me, so I never built one. If he would have included specifics on phasing line lengths, cable types, etc, the job would have been a whole lot easier. Has anyone actually gone circular with Cushcraft Four Poles, and if so, could you please share it with me and/or this group? I have done some inquiring to commercial companies about a custom built two meter four bay circularly polarized array, but that is entirely out of the question. They want thousands of dollars. There must be an easier (and cheaper) way. Similarly, is anyone in this group running circular polarization on your amateur repeater(s), and if so, could you please share the details in a manner that could be duplicated without a lot of guess work? I know that I could easily solve my multipath problem by installing one or more remote receivers, however I would like to keep that as a last resort and shoot for a circularly polarized antenna system at the main repeater site. I do understand that there is approximately 3 db of loss as a result of this, but that is quite acceptable. The dividends would greatly outweigh the down side. Thanks for any constructive ideas, suggestions, links, etc, that you might be willing to share concerning this situation. There's also a recent article in QST about a passive Lindenblad using an active dipole as a center section and four passive aluminum wires suspended from a plastic mechanism. I've looked at that and said... that wire/plastic assembly, and one of the old Motorola TAD series dipoles ... would make a DC-grounded circularly polarized antenna that should be good for a few hundred watts, and a minimally preferential (non-circular) pattern. You're in unexplored territory. The best way in is to locate a low-power FM station that upgraded to a higher-power transmitter, buy the antenna from them, and get Jampro to cut it down for your frequency. Of course, that's real dollars... anything else will be improvised. It would be a good idea to look at the terrain you're trying to cover and see what beamwidth fits it best. If you have the money to spec out an antenna with some null-fill and a lot of gain, like a customized DB-228, you'll find that coverage is second to none. Typically speaking, you don't need much antenna gain to cover close in to the tower because the distance losses are less. And you can always address that with a 1/4 wave dipole on the top of the building connected to a voter reciever. Theoretically speaking, circular polarization results when the vertical and horizontal components are 90-degrees seperate from each other. The Cycloid dipole accomplishes this simply, using a vector sum of the two to make circular polarization. It's synthesized -- 1/2 horizontal + 1/2 vertical = so many degrees hypotenuse. It gets complicated to start working up in those regions, almost to the point of designing panel antennas and putting one on each side of the tower to get a decent pattern. It's difficult to phase antennas and preserve some form of a pattern with them. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Motorola Saber Batteries
On Mon, 16 Aug 2010, Aristotle Zoulas wrote: Hello , I know this is not a Repeater Building questions but most of us either have or had Saber radios's. What is the best source of replacement batteries. I bought a 2700 mah battery from ebay and its way too tight, only goes on 2/3 of the way. If I forced it, I would definitely break the radio. Also, even though it was 2700 mah , it was half the weight of the original dead motorola battery. Thanks Aristotle Zoulas, KC2GBS Try taking the base plate of the radio off and putting it back on, if you have the spanner to unscrew it. You may find out there's a hairline crack in the plate, or that the terminals are sitting higher than they should be for that battery. As with a lot of aftermarket gear, there will be significant variations in workmanship and fit. I don't know what to make of the weight issue. I've never put the NiMH battery or the NiCD battery on a postal scale. I'll try to remember to try that out. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Re: Dielectric diplexer
On Thu, 12 Aug 2010, skipp025 wrote: brand diplexer rated at 25000 watts on 191 Mhz from a analog TV station. I feel a little bit like the dog that catches the car he is chasing. Now that I have it, what can I do with it? Any ideas? Can it go to 220? Does anyone have any experience with these? Thanks Bill N4XIR I'm thinking duplexer and/or cavities for any of the VHF and some UHF Bands if you do the proper homework. Even getting it cut down and welded back together, you could easily to 420-450MHz, perfect for that 421MHz 1.5kW ATV machine you're building. 220... oh but the cans must have a high Q -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] VHF REPEATER USING DELTA or RANGR
On Fri, 9 Jul 2010, tomnevue wrote: Has anyone made a VHF repeater using 2 Delta or Rangr radios? Were the results OK? Any unexpected problems? Yes, two Rangrs. I turn the TX power down to 50W (100W radio) and provide forced-air cooling in an air-conditioned room. No issues noticed other than deviation being low. I used the Mic input for the transmitter and the Audio_PA_Enable line in the control head for the RXCOS line. The radios are handling time-out timer (three minute max :-/) as well as CTCSS reception and generation. This machine has a fairly low duty cycle. In testing, it would back down to 35-40W or so and just stay there when the PTT was wired to ground. Kept it locked in transmit for 24 hours, no real issues noticed (again, at 50W, it backs to about 35W, which is sufficient to keep the heatsink cool). I mounted the radios vertically, with the heatsink up. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Erring on the Side of Caution....
On Thu, 1 Jul 2010, La Rue Communications wrote: Thanks Jeff! I am curious though - if the RSS is similar to Computer applications (I know the RSS *IS* software) but if its obsolete, a lot of software vendors don't mind if the obsolete software goes public / freeware. Even if it was made Open Source and people could configure it to work with any similar Motorola radio (If possible), would Motorola get upset about stuff like that happening with their licensed software? Motorola will sue you into bankruptcy if you cross them. However, they have larger problems. Remember that they are selling radios that cost $1500+ to every agency under the sun because of the narrow-banding that is coming up in a few years. The secondary markets of the existing wideband radios will be legal Part 90 users who do not want to pay for the new radios, and can afford the filter and frequency standard replacement as well as the tech's time on the bench to make sure the radio is within spec. On top of those factors, many of the radios weren't made to deal with the splinter frequencies which will be used in increasing numbers in the future. I suppose if one was bright and wanted to hedge a few bets, one could buy up a large number of Maxtracs, have them sent to China, install new timebases and filters, check them there cheaply, then send them back to the US and have them checked again, programmed, and sold to the other Part 90 users. Or one could have 900MHz Maxtracs turned into 450MHz Maxtracs, keep the 2.5KHz deviation, and use HearClear. That would be fundamentally changing the operation of the radio and might involve learning 68HC11 microprocessors and reverse engineering the radio. But those costs are cheaper in China, where the choice is do I want to eat today? versus Do I want to eat next week? or I still have four months before they foreclose. Of course, the growing dependence on CODECs to achieve bandwidth savings in digital radio sets an artificial obsolescence point in the lifetime of the radio. As long as the FCC and industry keeps thinking they can squeeze blood from a turnip, two-way radio will see smaller allocations and the Big Five telecom players will enjoy allocations in the multi-megahertz. But Motorola plays in that market too. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] RG-142B/U
On Wed, 30 Jun 2010, NORM KNAPP wrote: It is decent stuff but it has a silver covered copper clad steel (yes steel, test it with a magnet) center conductor. If you don't immobilize it after installation, you run risk of noise (and other problems) when the steel core breaks from metal fatigue. If it is free, great! Get all you can. Better to use (imho) RG400 or RG223u. (If you got to stay small). Connectors for RG58 are usually suitable, but in some cases specific RG 142 connectors are required. 73 Norm I second what he said. I'm in the process of trying to replace my RG-142 jumpers with RG-400. Also, RG-142, while well shielded, does have appreciable loss per foot at the higher frequencies. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] re: DDRR Antenna on a tower
On Fri, 11 Jun 2010, skipp025 wrote: Keep in mind the DDRR Antenna is a reduced size vertical polarized antenna and the Squalo Ho-Loop are normally considered full or standard size loop type antennas that are horizontally polarized. DDRR Antenna mounted on a tower? Only if there were no other decent options.Maybe, but I've never run into that situation. That would definately earn you the hammie award, which is a downward look from the commercial guys. Also, DDRRs are notoriously touchy about the local environment and tuning. Expect a 500KHz wide 2:1 and if anything changes within a wavelength or less of the antenna, it's tuning will change. In short, it's an antenna best used as a mobile, where you're likely to be able to keep it in tune. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Re: Advice on 40 year old radio tower
On Thu, 3 Jun 2010, dgrapach wrote: The pictures are here of the tower. http://s903.photobucket.com/albums/ac231/dgrapach/Old%20tower/Old%20Tower/ I am really new to towers and tower climbing. Here are a few points based on what images you have posted: 1) Immediately Agent Orange the base of the tower, the guys, and the base of the guys. 2) Thoroughly inspect each of the above points for any through or heavy rust where metal meets concrete. 3) Anything that is living in or on the tower should immediately be severed. The tree growing through the guy wire needs to be separated from the guy wire. By cutting it down. First above the line, and then through the line. You want to crack the tree away from the line. The entire tower must be safetied before any attempt to climb is made. Anything organic growing on it should be turning brown and dying, and all of the guy bases must be inspected and assured to be in the ground. Additionally, since this is a bolted tower, I would inspect all of the bolts in the bottom 10 - 20 feet for any signs of looseness on the way up. One of these towers might survive with a loose or missing diagonal. But if it loses two diagonals, it's liable to drop without warning. Any rust should be surface rust only. There are no splits in the legs, so it's good there, but without being able to see the base of the tower without foliage cover, or the base of the guys without foliage cover, there's no certain way to tell how safe it might be. Obviously, the farther apart the vertical legs are, the stronger the tower should be. Rohn 45 is 18 per side, Rohn 20 and 25 are 12 per side. Rohn 45 is a little more comfortable to climb. ;) -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Legal radios for a repeater
On Mon, 31 May 2010, WD7F - John in Tucson wrote: Ah ha! Now I have it...your job title explains the comment about Part 90. de WD7F John in Tucson For Part 90 use, something narrowband complaint because the deadline is a loomin'. Well, spending $2000 now is usually cheaper than spending $500 now and $2000 later. Even if it takes three years to implement; swapping out a fleet of 100 - 2500 radios takes time. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Legal radios for a repeater
On Sat, 29 May 2010, terry dalpoas wrote: I was asked the other day by a friend if you could use an older mobile (Micor, Mitrek, Mastr II and Exec) that has been duplexed for a repeater in GMRS, public safety, etc. I told them that I was pretty sure it was legal since the transmitters are FCC type accepted and as long as they transmit a clean signal. Was I correct on this? For ham use, literally anything as long as it doesn't cause harmful interference to other services. For Part 90 use, something narrowband complaint because the deadline is a loomin'. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] HT-1000
On Tue, 25 May 2010, Douglas wrote: I have a question, maybe two on the Motorola HT-1000 portable radio. On the Repeater-Builder's information webpage that talks about how to decipher the model number example: H01SDC9AA3BN The forth digit/letter defines the working spectrum example S for the range 470-520mhz, R 438-482mhz, etc. I am talking obviously about the UHF model HT-1000 Jedi series radio here. My question is,are there model R out there and secondly, how easy or difficult to retune the S model if the range is outside the Amateur Radio arena? Many thanks guys. You need to read the radio with RSS to determine what actually sub-range of those frequencies the radio is programmed/capable of. Or you can disassemble it and check the parts/modules against a list to see what band-specific parts are inside. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] White Noise on Micor TX
On Sun, 23 May 2010, Tim - WD6AWP wrote: I have a small amount white noise on the TX of a Micor repeater. It is most noticeable in the hang time but it's not coming from the controller. It's still there with the controller completely removed and pressing PTT on the station control card. It's more noticeable on some radios, perhaps radios with higher audio frequency response. Are you set up for transmitting a PL/CTCSS? -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Lost 10 volts in a Master II UHF Repeater
On Sat, 22 May 2010, Chuck Kelsey wrote: And sometimes scare the crap out of you! And they stink. They make a cool purple smoke with lots of sparks when they flame out! IIRC they contain an element you're not supposed to breathe because it only causes cancer in the state of California. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Coupling cavities, cable length, and notch/bandpass configuration
On Sat, 15 May 2010, spradio2000 wrote: Hello, I've been designing and building my own cavities, and experimenting to find out what works best. The current project is a 70cm repeater, but we are planning on a 2m repeater. My own design uses a length between 1/4 and 1/2 wave between the cavities, this looks better after tuning with the coupling loops. Before I continue with 2m cavities I'd like to know more about coupling cavities and cable lengths. What is wise, and is the setup with 2x twoo notches and one bandpass the best solution. I tried 2x tree notches. works nice but requires major retuning when connected to the repeater. I hope one has some good info, or knows where to find some. Oh, all interconnecting cables are RG400 double shielded, silver and PTFE cable. Did you calculate the distance to include connectors and velocity factor of the coax? 1/4-wave between points is normal; it also tends to have a transforming effect as well that helps with matching. Another thought might be to aperture couple the cavities. Then you won't have any cable or connector issues to deal with. The paging cans use this to reduce losses and increase power handling capability. -- Kris Kirby, KE4AHR Disinformation Analyst
[Repeater-Builder] Lightning Strike Detector
http://www.youtube.com/watch?v=1jP_D0S2CtY Watch this to the end. Build the chimes experiment using phone ringing bells. If you hear them next to the tower, run like heck! -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Multiple receivers on one antenna
On Wed, 5 May 2010, wd5etd wrote: Sorry for the dumb question but, I have a group trying to add a link at one site for 5 repeaters. They are not trunked. What is the cheapest way for them to share 1 antenna? They have a very good DB antenna but, I did not think it necessary for them to buy 5! They are out in the country quite a ways. So, there is not much else to interfere. I know a combiner is probably the usual way but, I thought there might be a cheaper way since it is only for receive. They do not have a tower for the receive antenna but, they do have a multi-story building. So, feed line expense is not a concern if they use multiple antennas. Cheapest way would be a band-pass cavity ahead of a cable TV distribution amp and a multi-port hybrid splitter. This assumes that the antenna isn't duplexed and used for transmitting as well nor are any of the transmit frequencies within the receive bandwidth. -- Kris Kirby, KE4AHR Disinformation Analyst
RE: [Repeater-Builder] Re: A warning to Land Mobile Radio Dealers
On Sat, 1 May 2010, Mike Besemer (WM4B) wrote: Kinda wandering off repeaters here, aren?t we? Brian Raker wrote: ?97.111 Authorized transmissions. (a) An amateur station may transmit the following types of two-way communications: ... (3) Transmissions necessary to exchange messages with a station in another FCC-regulated service while providing emergency communications; Yes, we are allowed to do so only while providing emergency communications. It's up to us to determine (hopefully with a good helping of common sense) what is an emergency. Actually that's pretty easy. See 97.403 and 97.405. We're way, wy off-topic. -- Kris Kirby, KE4AHR Disinformation Analyst
RE: [Repeater-Builder] Neat kit for switching repeater devices
On Sat, 1 May 2010, Eric Lemmon wrote: A fan blowing on a transmitter heat sink does absolutely nothing immediately after the transmitter is keyed, since the heat sink is likely at ambient temperature. It takes a period of time for the heat sink to warm up, so operating the fan prematurely is a waste of energy- which may be an issue for a solar-powered repeater. IMHO, the most efficient means of fan control is also the cheapest: A thermal switch. My first choice is a Cantherm #R2005015 normally-open thermostat that closes at 50 degrees Celsius, about 122 degrees Fahrenheit. When attached to a heat-sink fin, it turns the fan on when necessary, and keeps it on until the heat sink cools below about 100 degrees F- around body temperature. This particular switch is available from Digi-Key for about $9, as Catalog Number 317-1094-ND. If you're going to be using solar power for the repeater, it might be just as wise to invest in metal -- more heatsink area and better heatsinking. Like, for instance, the head off of an old air-cooled Volkswagen. If you don't need a fan, and the temperature rise is acceptable -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] fcc violation notice???
On Fri, 30 Apr 2010, Bill Smith wrote: Recon Scout is one that just received FCC approval for video in the 439 MHz area. I know about the Recon Scout. My name is all over the FCC's comments system rebutting the manufacturer's attorney. I'm at a bit of a loss as to why more amateurs aren't getting involved in trying to stop this misuse of spectrum. Even when the FCC makes an order, the affected users have a right to petition for reconsideration. I'm wondering if the device below is a Recon Scout, or if it is a device by another manufacturer. On Thu, 29 Apr 2010, Kirk Just Kirk wrote: For some odd reason POLICE DEPTS. think they are exempt from any frequency co-ordination!! There is one Law Enforcement agency here in Las Vegas that has a Robot device that receives it's commands on 154.570Mhz !!! WHAT THE HELL WERE THEY THINKING This freq is MURS-4, it's unlicensed, but it IS a licensed channel used by damn near every fast food eatery for it's drivethru window!! Can you possibly think of a poorer choice of RF freq to control a Robot on Dont get me started on the fact they use 439.250Mhz for the Video feeds!!! besides it being used for HAM ATV it's a very common cable TV channel!! What manufacturer makes this robotic device? -- Kris Kirby, KE4AHR Disinformation Analyst
Re: Re: [Repeater-Builder] Re: A warning to Land Mobile Radio Dealers
So if I had a UHF Saber, and programmed it to a Police frequency for the purposes of TX EMERGENCY info only like 911, then its required to have authorization? What if I was involved in a wreck and my radio was the only thing in reach over my cell? On Thu, 29 Apr 2010, dmur...@verizon.net wrote: You would go to Jail. Well, if it's your personal radio, that's between you and the FCC. However, keep in mind that your radio doesn't transmit your location like a cellphone does when you dial 911. I still wouldn't touch the button to TX unless you're certain you're bleeding out, or will otherwise expire in ten minutes without emergency medical care. For a customer? I wouldn't risk my business like that. If they can't show a letter from the licensee permitting them access to the system, and such access can't be verified with a phone call, no-go. Tell the vollies to stick to a scanner. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] fcc violation notice???
On Thu, 29 Apr 2010, Kirk Just Kirk wrote: For some odd reason POLICE DEPTS. think they are exempt from any frequency co-ordination!! There is one Law Enforcement agency here in Las Vegas that has a Robot device that receives it's commands on 154.570Mhz !!! WHAT THE HELL WERE THEY THINKING This freq is MURS-4, it's unlicensed, but it IS a licensed channel used by damn near every fast food eatery for it's drivethru window!! Can you possibly think of a poorer choice of RF freq to control a Robot on Dont get me started on the fact they use 439.250Mhz for the Video feeds!!! besides it being used for HAM ATV it's a very common cable TV channel!! What manufacturer makes this robotic device? -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Direct Strike Lightning Detector
On Wed, 28 Apr 2010, Chuck Kelsey wrote: My Dad used to have a small tower for his TV antenna. One Christmas we strung Christmas lights up the thing and they got left there for a couple years. All the coloring wore off, leaving bare bulbs (the old outdoor size of years ago). The tower took a direct hit one summer. Every one of the bulbs ended up with a burned out filament and a large black spot on the inside of the glass. The antennas were fine, TV was fine, but the scanner (with antenna on the tower) didn't make it. Took all summer for the grass to start growing again under the tower. Chuck WB2EDV That makes me think a bit. If you take and run fluorescent lights all the way up the tower, connected together with short copper jumpers, once the ionization voltage is reached, they will form a large conduction channel to the termination point. It might potentially be a lower resistance than that of the tower, although your neighbors aren't going to like it when The Big Tower lights up because the voltage from ground to the top is enough to bias the lights into operation. If you don't bond it to the tower, you could have fun. If you do bond it, you'll know when the strike hits. On the other hand, if you do get a direct strike, your neighbors will be picking up pieces of glass for months. You will too. =) -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Direct Strike Lightning Detector
On Mon, 26 Apr 2010, Jesse Lloyd wrote: I am trying to think of a way to detect if a tower at one of our sites gets a direct hit. I was thinking of paralleling a ground strap with Direct hit? Sure, look for anything that has the magic smoke let out of it. In a direct hit, something is gonna go. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Re: how far
On Sun, 25 Apr 2010, George wrote: well this amplifier is rated 90 watts you can see it on e-bay just type powerwave in the search. it has error eliminating computer inside and no distortion what so ever. i have it modified and use it at 450 watts and i pushed it with two power supplys that can put more than 120 ampers at 24 volts. the antenna is rated at 500 watts... i wonder why woud they do that...just to put out 5 watts? power over bandwidth. 90W on a 200KHz channel, combined with other channels... Take all that power amplification capability, and put it into a single carrier +/-4.5KHz wide and you've got a nice large peak on the spectrum analyzer. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Re: how far
On Sun, 25 Apr 2010, Joe wrote: Just be careful. At the ERP antenna output levels that you are playing with and frequencies involved, things can get dangerous for human exposure. Anything above 50W, an OET 65 RF Field Study must be done. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Re: how far
On Mon, 26 Apr 2010, George wrote: i looked at the pdf that you refering and there is requirements for mesuring if the signal is more powerful than 1640 watts and the antenna is 10 meters or less accessibel by people...my antenna is more than 10 meters above the closest person and the signal is less powerful than 450 watts. anyway magnetic fields have no effect at the human body...what so ever You'd think that, but have a gander at the FCC Rules, Part 97.13. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Mitreks as UHF Repeaters?
On Mon, 26 Apr 2010, Paul Plack wrote: Your heatsink approach, however, is exactly what I was talking about. I have several very large heatsinks originally designed for use with big SCR switching circuits which look to be more than generous for a 30w PA at 100% duty cycle. My first repeater was built from a 2w Repco exciter board repurposed from RFID service. It was supposedly rated for continuous duty, but had to run very hot to dump the heat it produced through the little aluminum tab mounted to its own PC board within the case. I fashioned a new tab with a 90? twist which allows sinking the little PA to the case itself, and it never got above warm to the touch, even after hours key-down. Guys, I appreciate all the input. 73, Paul, AE4KR Remember, the 100W Mitrek had a heatsink that was rated for 35W and used the duty cycle to keep things cool. If you do a case swap from a 30W radio into a 100W case, you could be fine for 100%, barring excessive temperature climb. My druthers would be to use an Original Syntor. It's got the helicals of a Mitrek, and the programming of a PROM. At $10 per frequency change (the going rate of the PROM chip), it's still cheaper than the Mitrek and uses the Mitrek/Motrac accessories. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Mitreks as UHF Repeaters?
On Mon, 26 Apr 2010, Paul Plack wrote: I am completely unfamiliar with the Syntor, cost, availability, etc., but I'm also early in the process of nosing around locally. I'm willing to look at any plentiful, high-quality radios for the conversion. 73, Paul, AE4KR Syntor -- not Syntor X or Syntor X9000 -- has the helicals of the Mitrek and excellent suppression of other nearby signals. The radio is only about 2MHz wide at widest tuning. Every other Motorola radio beyond them is 22-28MHz wide. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] OT: Programming Help Needed - Saber
On Mon, 26 Apr 2010, La Rue Communications wrote: I have run into a brick wall at a rather high rate of speed... as fast as DOS can run anyway. I am trying to figure out the band split of a (Presumed) VHF Saber Securenet Capable portable / handheld. I have the standard DOS RSS for Saber version 07.01.00 with a Moto Rib Box etc. I have programmed and read many other models of Sabers, except for this one particular model. Factory ID: H43TUN5170CN H43TUN5170xN, 6 watt, VHF Systems Saber I Model is H99QX + 104H, which I think is a package number. Google turns up that it may be a Military issue and no information can be found on this. Is this true? Generate a new codeplug in the RSS and dial the options around until you see a model tag that matches the above Model. That will tell you without reading what you're holding. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] OT: Programming Help Needed - Saber
On Mon, 26 Apr 2010, La Rue Communications wrote: Can you think of any reason why this radio will not be read by the RSS in the first place? All I get are Serial Bus I/O Error was detected. I know it seems like something not connected properly, but it reads all other models of Sabers just fine. This is the only RSS I have for the Sabers. COuld it be an improper version? John Hymes La Rue Communications 10 S. Aurora Street Stockton, CA 95202 http://tinyurl.com/2dtngmn Systems Sabers require Systems Saber RSS. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Pager Interference Revisited
On Sat, 24 Apr 2010, Mike Besemer (WM4B) wrote: The issue disappeared over the winter months. If it's a hot, sunny day you can be sure the problem will be present. A hot, cloudy day is also a fairly good bet. Also, a cooler, sunny day will bring it out. Cool and cloudy or cold and sunny do not allow the problem to manifest. The issue has been present during and after several days of rain, so that seems to eliminate the 'rusty bolt' syndrome. I tend to believe it's an amplifier mounted on a pole or tower someplace that's going spurious with heat, but that is just a theory. Beam headings tend to point to the paging transmitters rather than the possible mixing source, which is baffling me as well. Does the paging transmitter have a circulator, or a bandpass cavity between it and the antenna? Does it stay on one frequency or hop around? -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Is there an admin for BatBoards around?
On Wed, 14 Apr 2010, Dennis Wade wrote: Please excuse the interruption, but the site email appears to be broken as does the its registration process. If there is an admin for the BatBoard discussion site, would you please contact me via private email? Thank you. forums.hamsexy.com is probably a good place to register and complain. -- Kris Kirby, KE4AHR Disinformation Analyst
[Repeater-Builder] Motorola Spectra Question
Is anyone aware if the Motorola Motorcycle Spectra (M33) has a different final amplifier than the regular D33 or D43 models? Is the M33 setup with a 25W PA that is turned down to 15W and capable of operation at 10W? I do not have a manual for the radio, unfortunately. -- Kris Kirby, KE4AHR Disinformation Analyst
RE: [Repeater-Builder] Motorola Spectra Question
On Mon, 12 Apr 2010, Eric Lemmon wrote: I have several Spectra motorcycle radios, as well as the motorcycle supplement 6880103W01. Both my visual inspection and reference to the manuals confirms that the M33 motorcycle radios contain the same PA as the regular 10-25 watt radios, except that it is adjusted to 15 watts output. Range 1 radios (136-162 MHz) contain the HLD6066B PA, while the Range 2 radios (146-174 MHz) contain the HLD6032B PA. Thank you! I put a motorcycle Spectra into a go box as a portable station and turned it down to 10W. I wasn't able to verify prior to use that 10W was a Motorola-specified power level or not. Looks like my guess was good. Thank you for answering the other question I hadn't asked yet -- what the part number was for the motorcycle supplement! Do you have a master part number for the Spectra manual that should cover most of the radios? (By now it should be a -O part.) -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] crimping assistance please
On Mon, 12 Apr 2010, Chuck Kelsey wrote: Then I'm assuming that you'd agree that a typical ham-installed connector should probably have the center pin soldered? Chuck WB2EDV Whatever the connector is designed for. I solder them, my father solders them, and three or four two-way radio shops I know of solder them. I usually don't buy connectors that require the center-pin the be crimped. There may be connector fit issues after soldering. However, your typical ham-installed connector may be held on with duct-tape and baling wire, glow red hot at times, and simultaneously function as a 3x, 5x, 7x, 9x, and 11x multiplier and mixer at the same time. Or it may simply be slipped onto the coax, held in place with a friction fit and/or cold solder joint -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] crimping assistance please
On Mon, 12 Apr 2010, hitekgearhead wrote: I know this has been thrown around a bit before but I could use a little assistance. I just purchased a crimper and a couple sets of dies. I bought some cheap BNC and TNC connectors to practice with along with some RG-58A/U cable. I bought 3 different sets of dies. One of which is for RG-8 size connectors so I am not really concerned with that yet. The other two dies have hex crimp sizes of .324, .255, .215, .100, .068 and .215, .184, .068, .042 Obviously these two dies duplicate the .215 and .068 sizes. .215 is what I use for RG-58, .255 is used for RG-59/LMR-240/RG-8X. I think .68 or .100 is used for the center pin of either of those, but it's often connector dependent. The .042 crimp will be for the smaller varieties of coax like RG-174's center pin (or perhaps the micro-coax they use in the U.FL connectors.) If you look around, you'll find that you've equipped yourself to crimp anything from RG-6 all the way down to RG-174, and certain types of Fiber Optics. I'm a firm believer in investing in good tools. I think you've made the purchase of a lifetime, so to speak. You won't have to replace that crimper until you either wear it out or need to replace the jaws. Basically I am not sure what size hex to use for the above stated RG-58A/U and BNC and TNC connectors. .215. Also, I have a question regarding stripping the cable. I am not going to be doing high volumes of cables, but probably will be doing them on different size of coax. Would you recommend a stripper or will a razor knife suffice. If you're making a lot of cables, the stripping tools they make are excellent for speeding coax preparation. Most of them make cable prep easier than cutting copper pipe. Lastly, and relating to the coax strippers: Don't different connectors, even on the same type/size of coax, need different stripping lengths? This would probably translate into quite a few different strippers for different cables and connectors, no? You can kinda eye-ball this using a nice pair of strippers, a sharp knife, and some careful cutting. Just remember that you can't allow either piece to touch and that you don't have to strip to entire center conductor. Also, the shield should usually be cut back to just long enough to interface with the shield ring, preferably the entire length of the shield ring. I usually strip about 2 of RG-58 of the outer jacket, cut the shield down to 1/2 from the jacket, then start eyeballing to figure out where I have to strip the inner conductor to get it out of the end of the center pin. Or into the center pin, as the case may be. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Slightly OT: How are folks taking audio from multiple mobile radios and outputting them to one speaker?
On Sat, 10 Apr 2010, Will Gwin wrote: Personally I'd rather have each radio going out its own speaker. It works alot better when the speakers are mounted in different locations in the vehicle so you can tell which radio it's coming from without looking at it. Other guys I know that run multiple radios usually stick with really small speakers that they can stick right next to each other. Though I suppose you could spend a couple bucks and try some diodes? Another approach is to build or use an aircraft audio panel, which gives you two or three audio outputs. This is not entirely unlike the Motorola consoles that have select and un-select audio channels. Check out Bruce Lane's installation: (Controlling it all) http://www.bluefeathertech.com/kc7gr/thevan.html -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Xtals for Mastr ExecII
On Sun, 11 Apr 2010, Lee Pennington wrote: Crystek, And Jans, Both in Fort Myers, Fl..73 Last crystal order I put in, I mailed the ICOMs to International. I think the ICOMs were close enough to frequency that I didn't have to touch them. The last time I called JAN, I didn't get a call back, or a response to my email. Has anyone else had more recent contact with them than three months ago? -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Had at the hamfest
On Sat, 10 Apr 2010, AdamW wrote: Bought a Mastr Executive II unit today with the idea of making it into a UHF repeater. The seller indicated it was a 70 watt model, which would have been perfect. Once I got it home and opened it up, started looking at board part numbers and the Combination Number, it turns out I have one of the vehicular repeaters with a 300mw RF deck! ARGH! So, can I convert the RF deck to a higher wattage by adding the missing board in the PA (and where can I get one, and what would it cost?), or simply replacing the whole RF deck with one for UHF and higher power (same questions on this solution). Lastly, I could sell the radio to someone on here who might be able to build something out of it using other parts or parts radios they have around. You might be able to find someone here on the list two would be glad to trade your three watt radio for a high-power radio. Low power radios are good for linking. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Motorola Syntor system 9000 X help?
On Sat, 3 Apr 2010, AARON LEWIS DINKIN wrote: Salutations, I just recently acquired a Motorola Syntor 9000 X (as well as a Systems 9000 kit as well as a Spectra box) off eBay, and I'm in a bit of a pickle; I didn't realize how much of a radio I was getting myself into, because I only have previous HT (Yaesu VX-8R and Kennwood K2AT) experience, and I didn't realize how HEAFTY the Motorola was going to be. Motorola's philosophy can be compared to GM's; it's radio by the pound, and 110 watts is heavy. The Connector cables alone are so massive and confusing, I'm reaching out for help. I'm going to need someone to help me sort through all of the information from http://www.onfreq.com/syntorx/ as well as http://www.repeater-builder.com/motorola/syntor/syntor-index.html to help me sort through and reach a boiled down meat and potatoes step by step sequence I can go through to help trouble shoot the radio and HOOK IT UP TO MY VEHICLE. Should be a big red wire -- goes to the battery through a fuse-holder rated for 40A. Should be a big black wire. Goes to ground, like to the body of the car. The green wire on the control head goes to an always on low amperage source (think of this as RX enable) and the orange wire is wired to the ignition (think of this as TX enable). Plug the antenna into the SO-239 and watch anything not rated for 110W go up in smoke. Literally. I've melted a Tram 1180 in half with this radio. I've noticed the above sites recommend that I open up the radio to see if it's setup for a positive or a negative ground. But i really need help decoding the cables so I know what wires go where? I need to decode which wires are for the SIREN, the LIGHT BAR, the Vehicle power, etc. The Syntor X9000 uses RS-485 between each Systems 9000 accessory, along with a differentially signalled BUSY line, so you won't be able to sort out siren and so on. The Syntor X9000 is the first of the radios that was able to be programmed from a PC, and uses RSS. It cannot be programmed using any of the Syntor X tools. their own microprocessor inside. Unlike the Syntor X the X9000 is programmed with RSS (and a slow PC), a RIB and special adapter cable that goes in series with the normal radio cable. The the special cable is not an absolute requirement; there are several ways to make your own connection from a radio to a RIB. In other words, the X9000 is a more desirable mobile radio than a Syntor X since you don't need the almost-impossible-to-find suitcase programmer for the plain Syntor or the Syntor X... you just connect a slow PC or a laptop to the X9000 and program it. The RSS package for the X9000 contains two programs, one to program the radio, and one to program the head (you program the radio with the information (frequency, tone, etc) for each mode, you program the head with the text to display for each mode). That being stated, there's a company that's called http://www.piexx.com/ they make a mod, http://www.piexx.com/index.php?main_page=indexcPath=5 it's primarily for the Syntor and the Syntor X lines, it allows the unit to be more easily programmed. So instead of using the hard to find suitcase programmer you can hook your system to a Win9X based or WinMe based system to program it, instead of having to hook it to a Slow PC Running Real DOS. This doesn't work for the Syntor X9000, which is a different radio than the Syntor X. Before you even THINK of making a reverse hybrid (converting a Syntor X9000 to a Syntor X), contact someone on the list. Someone will have a Syntor X somewhere they will be happy to outright trade with you. I was curious if there was a way to apply this mod to the 9000 X Series, I understand it won't necessarily be a TRIVIAL mod, but I'm up for the challenge if someone's willing to help walk me through what I need to do! You're in unexplored territory. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] D-Star Was: Molotora Gontor
On Sat, 3 Apr 2010, Nate Duehr wrote: Actually they did an okay job on the radios, JARL did a really piss-poor job on the streaming standard, The radio interface isn't so bad until you get into programming all fourteen menu items that have to be set to make communication happen through a repeater. I still think it needs a beacon channel like APRS which would allow the radio to be aware of what repeaters are around it so the system may route the call according to what repeater the user can hit. But that might make it too much like trunking radio, and would require another duplexer and a second frequency. and Icom REALLY screwed up the distribution of a Linux server... (Build Apache from SOURCE CODE as a normal way to distribute the software?! Really Icom? Okay, welcome back to the 80s... thanks...) Agreed. That and completely NOT understanding NAT and RFC1918 space, as as well as requiring pre-CIDR routing make it a toy. Realisticially, you don't need to know anything about routing, and way they decided to implement it precludes current subnetting practices used in AMPR.ORG (44.x.x.x/8). I like D-STAR as a not-very-well-designed first try and use it... but it's seriously technologically flawed. Some of that can be fixed... other things like the header information not being interlaced... There's always DSTAR v2.0... If ICOM is willing to release a flash tool for the radios. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] D-Star Was: Molotora Gontor
On Sat, 3 Apr 2010, Nate Duehr wrote: p.s. Before anyone thinks this is a plug or a rant either way for or against any technology mentioned above, be advised that I've been working on bugs like this my entire career, and watching engineers make the same mistakes over and over and over again in the wireline telco world. I gave up picking favorites long ago... almost every data protocol out there sucks, in one way or another. This is not limited to data and RF, it's all over anything attached to a computer. I gave up working in computer security because it was always the same thing -- someone would write software wrong, not test it, ship it, and it would be the way that a customer was broken into. Of course, if that customer had followed the recommendations of the security consultant, the break-in wouldn't have occurred, but the CxO made the decision based on cost vs risk to skip implementation of that system. I can explain how to break X.25, Ethernet, Gigabit Ethernet, Token Ring, IPX, IP, Q.931 messages... ahh, pretty much anything -- 'cause I've seen customers do it. Invent a better protocol, someone will invent a better idiot. I've been that better idiot. I'm continually amazed at the bugs I find in exercise equipment, cars, etc. Failure or unexpected situations are not tested for, because testing is expensive and only performed once someone gets hurt or killed. I think we're trying to teach people this stuff so fast these days, they have no idea what you're talking about when you ask them to measure the voltage on a T1 circuit... or try asking someone to measure the voltage on Ethernet sometime. Trying to understand digital RF communications is like drinking from a firehose. And most college students are more interested in graduating and/or doing all of those things that college students do. When it comes to RF digital protocols, the entire classroom full of hams would fall asleep long before you got past the basic framing of the circuit, let alone talking about how a double at the RF/Air interface would affect it. Well, we do this as a hobby... Wireline techs have no concept that ELECTRICITY and all the E=IR and other properties that go with it... are actually traveling down those wires... they do seem to get it that when they replace it with plastic fiber optics it all works faster/better... but then they bend the cable beyond the bend radius allowed for the fiber, and wonder why it all falls apart again. NO CLUE about the physical world, just that you're supposed to plug it in and type some commands and it'll magically work for you. Again, this isn't limited to wireline techs. There's an entire generation of Americans who know only that one thing they do, and have no desire to learn anything else unless the boss tells them they need to know it. In an earlier time, these individuals would find themselves out of a job. Thus, the folks who REALLY know it -- really need to try a little harder to make the on-air interfaces bulletproof, and ALSO to make sure the products are also released with TEST GEAR that any moron could operate. Seriously. We all know from reading here on RB that just understanding all the gotchas of FM analog, and repeaters, is many years of study. Add the requirement that the repeater operator also should magically understand routing protocols, IP, on-air framing formats, and all that jazz? There are many man-centuries of experience on this list. But I agree. I think that Motorola and some of the other companies haven't put thier best talents on writing protocols and designing products. It'll be a while. Ask any agency who deployed P25 when it first came out how many years it took their best techs to really UNDERSTAND what was going on in the system on a day-to-day basis... or if they even really believe they do, yet. I find that the best techs tend to be reverse engineers. Unfortunately for them, they are under-paid and usually unrecognized among thier peers. The company brought in a trainer a few years back to teach logical troubleshooting. Three clues in, I gave the answer. The trainer said, How did you DO that? Before I could reply, my boss (kindly) said, We didn't hire him for his personality! My favorite answer is: I think with both halves of my brain at once. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] D-Star Was: Molotora Gontor
On Fri, 2 Apr 2010, Scott Zimmerman wrote: Around here (Western PA) the governments bought Icom D-Star radios for RACES. I had no objection to that since those radios can be used in analog modes with analog repeaters. Now they are wanting to get D-Star repeaters for RACES and emergency use. I *strongly* object to that since they CANNOT be used in analog modes for emergencies. In my view, you'd be alienating much of your volunteer base that doesn't have the correct equipment right at the point where you need all the help you can get! Of course with the government in the mentality that they have been in the past few years, maybe that's their way of thinning the heard. There's also a substantial base of users who like D-STAR because there isn't a scanner that can decode it. This provides the benefits of an encrypted channel without the encryption. IMO, any use of this mode for that purpose is strictly against the rules. I'll take my analog Motorola Saber with a 2700mAH battery any day over a ham HT for being out in the sticks or having to transmit/receive for eight or more hours. When the battery dies, I can at least bludgeon a squirrel to death with it and get a meal out of the radio. Disaster situations are about survival. Individuals who go into a disaster situation need to have basic survival skills, plan to carry everything in that they need, and to have a way out. Skip the air-conditioner for the shack, pack an extra water tank, and pick the most effective radios you can for the job. They should all be MIL-810E tested or higher. -- Kris Kirby, KE4AHR Disinformation Analyst
RE: [Repeater-Builder] D-Star Was: Molotora Gontor
On Fri, 2 Apr 2010, Doug Bade wrote: I would be glad to elaborate about D-Star Repeater conversions as there are multiple ways to do it now and Any EDACS capable or Smartnet Capable repeater would do D-Star as both fundamentally have the parts to transmit and receive GMSK type waveforms There is one issue that needs to be handled. When a D-Star repeater hears another user on the input for a callsign not it's own, the modem is captured, and any input packet that starts or is received in the middle of that transmission is discarded. This, of course, would not be permitted in the Motorola world; something would have to be done with the received information, even if a band-opening allowed a remote digital user to interfere with a digital trunking system's input channel(s). Practically speaking, I think that the earlier data should be thrown out, and the packet decode restarted with the new signal. Of course, short of doing SDR and de/re-coding on the fly, this is not a trivial problem to fix. When your RSSI is measured as BER, it's a different world. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Nice article on the Molotora Gontor
On Thu, 1 Apr 2010, Kevin Custer wrote: Bob Meister has written a nice article on the Molotora Gontor for RB. http://www.repeater-builder.com/molotora/gontor/gontor.html Thanks go out to Bob for his efforts! If it front-panel programmable (FPP)? -- Kris Kirby, KE4AHR Disinformation Analyst
RE: [Repeater-Builder] Helix / Connectors
On Tue, 30 Mar 2010, Jeff DePolo wrote: Aluminum-shielded cable isn't anything new. It's pretty much the standard in CATV, and was quite common in two-way back in the day as well. Andrew, Prodelin, Phelps-Dodge, et al made different flavors of it, both corrugated and smooth-wall, jacketed and unjacketed. I've had way too many problems with aluminum shielded cables to ever consider buying it again. I'll spend the few extra pennies on the good stuff (copper). When you're pricing out 440 feet of coax, the pennies add up to quite a few dollars. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Re: Anyone get RSS for MT1000 to run on a Dell M70 in DOS?
On Mon, 29 Mar 2010, Fuggitaboutit wrote: there was all this talk about the old uarts in the older machines which i dont really believe if you can get the sofare to run in a dos box then great it wouldnt matter how new the machine hardware software is the spectra radio here works but the grief i would have to go through to get the radio to communicate with anything is not worth my time The problem is that the timing loops associated with serial communication in that software run too fast on modern hardware, causing the software to try to talk to the radio faster than the radio is capable of writing to its firmware. i386 virtual machines are great, but it is possible to have something execute in that virtual machine at 2+ GHz today. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] 10 Meter Questions
On Mon, 29 Mar 2010, N8FWD wrote: How far apart does my TX and RX in air miles on 10 meters have to be for a 150 watt transmitter? Can I put a ider on the rx site and let it id through the link and through the transmitter and be legal or do I have to Id at both sites? The rules read that all transmitters must be identified. You should have some form of timeout timer to prevent the TX from locking up on the air if the link RX fails. Looks like 67 dB at two miles (10,000 feet). http://www.repeater-builder.com/antenna/images/horizsep.jpg To get another 3dB, you'd have to double the distance. 70 dB = 4 miles 73 dB = 8 miles 76 dB = 16 miles 79 dB = 32 miles 82 dB = 64 miles 85 dB = 128 miles 88 dB = 256 miles 92 dB = 512 miles I'd say put the two radios as close together as possible within the groundwave radius of coverage of either. Then attenuate the transmitter as much as possible, or notch the transmitter's pattern in the direction of the receiver. -- Kris Kirby, KE4AHR Disinformation Analyst
[Repeater-Builder] Helix / Connectors
Andrews LDF4: Any thought, comments about L4TNF-PS vs L4PNF-RC? -RC is a captivated pin connector which is gold and silver, the other connector is bronze inner, trimetal housing. I'm thinking that the less potential metal interaction, the longer the coax will last. I've also seen Trilogy listed in the same transmission line category, which uses a solid aluminum tube for an outer connector and a solid copper tube for the inner connector. The only issue I see there is the thermal expansion coefficient, or how much is my cable gonna grow from cold to warm days? This needs to last a decade. Station is not duplex, (originally quoted as LMR-600), but since the install needs to last a decade, I need good stuff. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Re: 10 Meter Questions (we've got answers)
On Mon, 29 Mar 2010, skipp025 wrote: We have a fairly local 10M Repeater here in California running that power level at the same site. Just a question of protecting the receiver and the transmitter. It's not super hard rocket science to make a 10 Meter Duplexer from 1-5/8 inch hard line if you can't find surplus cavities. Those coax stubs can be touchy to vibration. I wonder if they'll change appreciably if you mask off a part of the inner conductor, spray krylon down the tube, then fill it with expanding foam? Might make it a little less vibration sensitive, provided you don't destroy your tuning range. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Re: NOS GE Phoenix For Sale
On Sun, 28 Mar 2010, Joe wrote: Which mike are you looking for? I may have a NOS one somewhere, handheld with Whelen written on it. MCH wrote: I think the 200 was 16 channels with an option for 32 channels. While I'm typing, does anyone have a source for a replacement Whelen microphone element? I can't justify $150 for one from Whelen. Even a source for a good used Whelen mic would be welcome. And sorry about the off-topic post relative to the subject. Please direct any replies to my email address rather than the list. It would be cheaper to ask around and see if someone has a microphone that some dip destroyed out on the road, and put the Whelen cable on the two-way mic. Most of the Motorola - MA/COM mics are made by Shure anyway. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Maxtrac Channel Control
On Fri, 26 Mar 2010, Mike Morris WA6ILQ wrote: As far as I know the early Maxtrac did not implement Channel Steering (Motos' name for binary channel selection). You needed to use a late Maxtrac (more precisely one with the late logic board), a Radius LRA series or a GM300 to get that feature, and then you had to do some very careful programming of the radio to get 4 bits of channel steering, a RUS pin, and a transmit PL encoder on/off pin. What does this look like in RSS? Is it specified in the pin selection? I looked in a recent Radius firmware and didn't see anywhere that I could enable or disable channel steering by the pins. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Question about antenna seperation
On Fri, 26 Mar 2010, James Adkins wrote: We are considering installing a 2-meter repeater, standard 600 kHz spacing, with separate antennas for transmit and receive, looking at phasing together 2 DB-228's for RX and 2 DB-228's for TX and using a high-power transmitter, such as a Motorola Nucleus at 250-300w or other high-power transmitter. Does anyone have a formula or know what formula would need to be used to determine the amount of vertical separation needed to provide the isolation required for such a duplex operation? We are wanting separate TX and RX antennas because of plans to have the repeater on a platform located 1200' in the air, and heliax runs are not practicable. There's a chart on the repeater-builder website from GE's older information. http://www.repeater-builder.com/antenna/thoughts-on-isolation.html http://www.repeater-builder.com/antenna/separation.html In short, you're going to have a lot of coax in use already with a DB-2216. You should still have cans on the receiver side, as well as a notch can (rated for the power level) on the transmit side. You may be able to locate the appropriate notch-type can from paging company surplus. Typically they have 7/16 DIN connectors and are aperture coupled between cans. The receive side will need a notch cavity for the transmitter frequency, and some form of a bandpass filter to prevent other signals from causing front-end overload. Just one DB-228 at 500+ ft HAAT will cover out to 100 miles. There's a repeater 35 miles northeast of my apartment that I can work on an HT in my living room. I sit at about 900 ft AGL; the repeater is at 1300 ft AGL. I can work the machine from the laundromat as well -- at 750 ft AGL. I wish you much luck in this endeavor. It's a big project indeed. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] RG21AU CABLE
On Wed, 24 Mar 2010, Doug wrote: Can someone tell me what the characteristics of this cable are. I tried google and it didn't seem to know.. I sort of think it might be a lossy coax but not sure. http://www.rfparts.com/coax_specs_rg.html -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] RF Fuses
On Sun, 21 Mar 2010, Thomas Oliver wrote: How about Making one out of an old polyphaser housing just remove the guts and solder in the pico fuse. Should remain closer to 50 ohms if than putting a couple of chasis mount connectors on a metal box.. Let's see, we can calculate voltage on the line by reading the SWR or VSWR. I've never read into calculating RF amperage, but I assume that it would be calculating the amperage feeding a fifty-ohm load from the VSWR. Can someone correct me on this please? -- Kris Kirby, KE4AHR Disinformation Analyst
[Repeater-Builder] Scanning Tip
When trying to figure out how involved scanning a manual page may be, try inserting a piece of 11x17 paper up to the spine of the book. The paper will serve as a guide as to how the document may be scanned, since most scanners are either 8.5 x 11 inches or 11 x 17 inches. By looking through the paper, the person scanning may determine to make one, two, or three attempts to scan a given sheet of paper. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Ctcss detection
On Sat, 20 Mar 2010, kerincom wrote: Hi guys .A long time ago there was a series of post over the ctcss detection time and I am wondering if anyone can suggest which radios are the fastest on ctcss detection From what I've been able to determine, unaided by equipment, the Motorola Saber appears to enable the audio PA (speaker pops) at about the same time whether on carrier, PL, or DPL squelch. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Re: [rfamplifiers] Return Loss Bridge Kit
On Wed, 17 Mar 2010, kb8stb wrote: I have an MFJ 269 (i know its not a precision instrument...) but at the hobby level is there any reason for me to think about building this thing? What does it do (even the $498 one) that my 269 dose not? (ignoring the precision issue) I ask in hoping to learn something more about radio and test equipment. I figured out quite by accident one night that an MFJ-259 and a directional coupler can be used with an HP-141T to simulate a tracking spectrum analyzer. By using the analog storage function of the scope, you can verify what the output of the MFJ-259 is when feeding the directional coupler into a dummy load. Then reverse the directional coupler, and the sweep should be flat and low-level if there is a dummy load on the coupler. Finally, you attach the antenna or other device and look at what power is reflected. I had the benefit of being able to do this in a number of different ways, using an isolator shelf with a 250W dummy load, -30dB directional coupler, and my other directional coupler of unknown rating. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Low Band Micor mobile not making power
On Thu, 18 Mar 2010, tahrens301 wrote: Working on a micor mobile to be used as a repeater (only using the exciter/control board/PA). Was going through it, and am only able to get about 75 watts out of it with the exciter on 53.7. The exciter is putting out 0.3 watts... a bit more than most exciters I've seen, but they were high band. The tags on the PA cover indicate over 100 watts were once measured. Made most of the capacitor mods to the exciter, but it tunes up easy. (slugs not in wierd places). Oh, not gonna run it at full power, but wanted to make sure it was up to snuff. IIRC Motorola usually used about 1W at the exciter to drive the PA to full power. 1.125W (+33dBm) will put a Mitrek amp up to 125W under certain conditions. The Micor may have a tripler though. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Low Band Micor mobile not making power
On Thu, 18 Mar 2010, Tim Ahrens wrote: I asked the guy I got them from if he had an extra exciter, as one of them seemed to have some parts missing. Anyhow, he said oh, that maybe one that was setup for digital. Evidently they came from an oil company, and they were a bit 'special'. Early DVP and DES systems used a 16KHz-wide data signal. To repeat these through the repeater required re-clocking modules. That may be what you're seeing, that or a DCS(DPL)-type module. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] cor location in an ic-2200h
On Tue, 16 Mar 2010, Nate Duehr wrote: This I want to build a portable repeater question comes up so often, I wonder if someone has time to turn it into an article for RB... Give me a minute (I mean a month) and I'll write something on how to do it right. Oh, but it takes two suitcases... -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] cor location in an ic-2200h
On Tue, 16 Mar 2010, Paul Plack wrote: Russ, you may have to spend more on whatever you're using for power than you're saving with those radios, as they pull 1.6 amps combined even on standby receive. Also, develop a plan to keep the transmit radio's heatsink cooled, even in low power mode. But plunging ahead... Suitcase repeaters require either power efficient radios, or low-duty cycles. Otherwise you're carting out battery boxes bigger than the radio box. Your controller can work with either COS (carrier-operated switch) or derive that signal itself. If you can find COS in the Icom radio, you don't need discriminator audio, and can couple audio from anyplace handy, including the external speaker jack if it won't be accessible to passersby. You will need to lift one side of a capacitor on the controller board to use de-emphasized, non-discriminator audio. On the other hand, if you can provide the controller discriminator audio, you don't need COS - the controller will make its own. The CES docs actually seem to favor this approach. The 2200 doesn't provide the needed signals on its accessory connector, but there are leftover pins there you could use to get disciminator audio and COS out of the radio cleanly. Get the owners and service manuals, available through online search. 73, Paul, AE4KR None of this is going to work if his objective is repeating D-STAR information. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Controller order , paypal problems
On Tue, 16 Mar 2010, John J. Riddell wrote: Some of you will recall that I had problems with Paypal when ordering a repeater controller. I sent two E mails to paypal and got no satisfactory reply...just stock answers I then called them to find out why they sent an E Check for my purchase instead of an instant money transfer. Again the lady read from a script and after asking her several times why they handled it this way, she finally told me that they have instituted a new security measure. When a purchase looks suspicious to their Computer, it decides to send an E Check which can take 10 - 15 days to clear. Is there any way to prevent thisno. since no human gets to see this transaction. This might happen in 1 - 2 % of the transactions that they handle. In my case the amount was $185.00 and it came out of my bank account instantly but their computer decided that it might be suspicious ! So hopefully this information is helpful to anyone using Paypal to make payments. I've used them many times in the past and never had a problem until now. John VE3AMZ It's because terrorists are Canadian. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Re: HAM Mototrbo Systems
On Sun, 14 Mar 2010, Nate Duehr wrote: That's one of the mildly interesting things about TRBO, it's not a Public Safety system. It's commercial, but rarely used in Public Safety... Perhaps what you're saying (paraphrased here) is MotoTRBO is D-STAR done by Americans.? LOL... that'll get me in trouble, I'm sure. D-STAR requires too much work to be effective at message passing for any one except for the technically inclined who like to push buttons. It is trunking radio, minus the control channel, and all of the functions performed by the control channel are delegated to the user. MotoTRBO would be akin to an LTR system, or another trunking system, with the built-in capability for handling high-speed data. High speed as in 9600 bps, not 100-200 bps. If there is one thing that seems certain in the PS arena, it is that Motorola is trying to sell every solution except something APCO-25 compliant, and attempting to confuse thier customers into purchasing systems which are not. Not to say that they have bad ideas -- MotoTRBO brings in the experience of iDen to two-way radio, but the FCC pushing for more narrow-banded technologies, not dual channel solutions. Am I fully OT or not? If so, I'll STFU. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Re: HAM Mototrbo Systems
On Fri, 12 Mar 2010, Nate Duehr wrote: It's well-implemented, and as one local pointed out... it behaves like I expect a commercial radio system to... he was comparing to D-STAR where you *have* to fidget and mess with callsigns, etc... to really utilize all the features... in TRBO, he switches the rig to Channel 1 to talk locally, and Channel 2 to talk to a pre-defined group of IP-linked repeaters... obviously, this is dirt-simple, and keeps the complexity for the user away, and places the complexity choices on the system operator/administrator. Not as flexible by any means, but sometimes you're just looking for it to just work. Don't forget that a public safety radio system and a Japanese ham protocol are two different things. The Japanese language is ideological, English is something else. We don't think the same, or implement things the same ways. That being said, if you've ever needed or wanted just work, you know how important that is. It's probably what's been lacking in almost every ARES plan. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Antenna Phasing Question
On Wed, 10 Mar 2010, afa5tp wrote: I have three (3) Antel [BCD 80010] 806-900 mHz vertical antennae that I would like to mount on the three legs of my tower for omni pattern (Rec. only). Several questions come to mind. 1.) At the rated frequency, how many inches should the side arm place the ant. from the tower? 1/4 wavelength from a large plane reflector, mounted in the middle of the reflector. 2.)What would be the best way to phase the antennae? I have a Andrews three port Splitter, and will use LDF4-50A for feedline. I would suspect the length of the pigtail from each antenna to splitter is going to be critical...or not, for receive only? 33% to each side, 120-degrees electrical length (I think). And be sure your tower can take the windload of sheet aluminum on all faces for 1.5 wavelengths below and above the omnis. Look at a feed arrangement for a big wheel antenna that has three petals instead of four. -- Kris Kirby, KE4AHR Disinformation Analyst
[Repeater-Builder] GE Delta S990 Head Question
Has anyone succeeded in getting the alternative S-990 head firmware to work? If you have, please email me as I am having some difficulty. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Noise Level on a Duplexer
On Wed, 10 Mar 2010, Kent Chong wrote: Yes, we found that the interconnect T-Join between two system is heated up. Could we just cool down the T-Join for there is other way to solve this issue? Replace the tee. It has failed, or one of the connectors attached to the coax has failed and the heat is conducting into the tee. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Pion and Simon
On Wed, 10 Mar 2010, John J. Riddell wrote: I ordered a Pion and Simon PSE 508-3 controller and have not received it yet here in Florida. They don't answer E mails and I can't find a telephone number for that company. Does anyone know their tel number ? Are they still in business ? 541-273-8958 does not work..This is the number shown on Paypal. 73 John VE3AMZ Last time I bought a controller from them, it took a long time to get here, like about a month. But when I ordered one from ICS, the lead time was like 60-90 days. I actually forgot I had ordered it when it showed up. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Pion and Simon
On Wed, 10 Mar 2010, John J. Riddell wrote: Thanks, James.but you'll recall that my question was for a phone number. I sent two E mails with no reply..to the address shown... Bear in mind that some people don't reply to emails because they are working on whatever spawned the email. -- Kris Kirby, KE4AHR Disinformation Analyst
[Repeater-Builder] Writing Guidelines
I see the guidelines for writing; what are the guidelines for scanning documents? -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Re: 200 watts on a repeater transmitter - was something else...
On Mon, 8 Mar 2010, nj902 wrote: It should also be noted that he is planning a system with voting receivers. It is very possible that these receivers will improve the talk-in sufficiently that the system will be talk-out limited even with 200 Watts. Until he has those recievers deployed and working, it's an alligator. --- In Repeater-Builder@yahoogroups.com, Kevin Custer kug...@... wrote: We have been over this many times. If a system is balanced with a receiver at -116 dBm running 50 watts of power, then it will be balanced with 200 watts and a properly deployed preamp adding 6 dB of gain. The added power level on the repeater transmitter helps with noise that is common in urban locations experienced by the mobile; noise that is not experienced by the repeater receiver. ... I think that one would be better served by choosing an antenna appropriate to the purpose of the repeater. If you need urban coverage, choose an antenna with more null-fill, or less gain. If you have to pay for power (or make your own power!), you'll spend more time working on an antenna that will cover what you need so your transmitter can be ten watts or less. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Re: 200 watts on a repeater transmitter - was something else...
On Mon, 8 Mar 2010, Kevin Custer wrote: The antenna doesn't know if it's receiving or transmitting - so the antenna has absolutely nothing to do with transmit or receive balance - which is now the subject. Kevin brings up an interesting point: If you want to verify the pattern of an antenna at a given frequency, RSSI may be for this purpose when attached to a receiver. One only need to calculate the pathloss and know the remote transmitter power. -- Kris Kirby, KE4AHR Disinformation Analyst
RE: [Repeater-Builder] Re: Fw: FCC RO Involving the Amateur 70cm Band
On Thu, 4 Mar 2010, David Jordan wrote: My guess is the manufacturer doesn?t have the technology or funding needed to build the cheaply made, significantly over priced crawling camera to operate in the GHz ranges. My bet is that the manufacturer got a deal on some 433MHz camera modules from China. Like BPL?this vendor will disappear once their venture capital has been all used up. The military may purchase some of these units but with tax revenues down nationally, for the next several years, I don?t think your local fire or police dept will be spending many dollars on this low value technology? Doesn't matter; the legal world is ruled by precedents. This sets an unhealthy one. And NTIA/Military has spoken up on the matter -- did you see the section in the order where the device would not be operated within so many miles of several AFBs, which are known to house PAVE-PAWS installations? -- Kris Kirby, KE4AHR Disinformation Analyst
[Repeater-Builder] Super-band TV Transmitters
If there are any TV engineers on here who have or have maintained a VHF superband transmitter (174-210MHz), please email me. I have some questions, and wonder if you still have schematics. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Fw: FCC RO Involving the Amateur 70cm Band
On Wed, 3 Mar 2010, George Henry wrote: Re: the waiver request by ReconRobotics for 420 - 450 MHz operation. Hams get the shaft again... Who wants to be the first to sue the FCC? -- Kris Kirby, KE4AHR Disinformation Analyst
RE: [Repeater-Builder] Fw: FCC RO Involving the Amateur 70cm Band
On Wed, 3 Mar 2010, David Jordan wrote: There are plenty of options?the FCC has set aside spectrum just for Public Safety and such devices, but they need input from us or all they hear is the vendor biased story?not sure why the FCC felt compelled to allow this request. Perhaps the vendor was concerned about building attenuation. I believe the erp of the devices is extremely low. Guys, they have authorized a user to transmit NTSC video in a section of spectrum reserved for RADAR; NTSC video has no previous nor presently known use as RADAR. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Narrow Banding versus Marine Channels (OT)
On Tue, 2 Mar 2010, wd8chl wrote: No. Narrowbanding only affects Part 90, and Marine is Part 80. It should also be noted that VHF Part 80 cannot be narrowbanded without an International agreement. That means it's not likely to happen for quite a while yet. Much like switching aeronautics to FM instead of AM -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Mitrek problem
On Mon, 1 Mar 2010, kernkampj wrote: Recently I had a problem with a Mitrek radio, The RX channel element would not reliably start oscillating on power-up. In my experimenting, I discovered that the problem related to the power supply I used. I had four power sources - two linear supplies, one switcher, and a battery. One of the linears and the battery worked fine. The other linear and the switcher created the non-start problem. I finally noticed that the radio has two internal power sources for the channel element (9.5 Reg and 9.5 switched), and wondered if the timing of the two sources could be the problem. So I slowed down the 9.5 switched source, and that cured it. The channel element now starts every time from any of the power supplies. For those interested, I added a 100uF cap from the base of Q1 (the receiver 9.5V Switched supply) to ground. This slowed down the voltage output of the 9.5 switched source. You might have one or more electrolytic capacitors which have dried out. I think the last Mitrek rolled off the line before I was born, which is longer ago than I'd like to admit. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] 900 meg Spectra radio
On Mon, 1 Mar 2010, Nate Duehr wrote: That's the reason I asked. There's a major manufacturer making a pretty decent 1.2 GHz radio (Icom ID-1) that costs $1000, and it's obviously also (besides doing FM) a D-STAR rig, and that distinction is making it sell to those with $1000 to burn on a digital mode... but a 900 MHz FM Analog with no hook feature to pull people in, I think would sell dismally, and therefore would have to cost at least that much... Come up with an idea and sell it to the fine gentleman from Starkville, MS. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Re: LOOONG audio runs
On Sat, 27 Feb 2010, JOHN MACKEY wrote: Using balanced audio in a broadcast environment, I have on rare occasions experienced issues with cross-talk between long runs of un-shielded balanced audio lines. (inductive pickup??) I always wondered if the wires were truly balanced when that happened. That's probably NEXT or FEXT, which is near-end cross-talk and far-end. Bell documented this stuff somewhere; I've read the book. There's a reason why they don't run the T1 lines with the voice lines or why they don't stuff the entire binder full of T1s. Of course, that same book explained how to use the cable pairs as resistors to heat up the cable, which has been done a few times in NYC, resulting in dead pairs in the cable due to too much power/heating on a given pair. -- Kris Kirby, KE4AHR Disinformation Analyst
RE: [Repeater-Builder] Re: LOOONG audio runs
On Sun, 28 Feb 2010, Chris Curtis wrote: My favorite is direct burial + shielded cat cable. I've got some here that I've been using for controller to device hookups. As well as the run from the house to the shed. Shielded with 100% foil and a joke of a braid. It is flooded with goo to keep the moisture out as well. Nice stuff for the $$ Of course, there's always fiber, but now you have to have power sources at both ends. Interestingly enough, I've watched the price of fiber come down over the last ten years, aside from changing connectors and increasing patch-panel capacities... Once it is installed properly (and people critters kept away) the stuff will last through a few generations of switch equipment. -- Kris Kirby, KE4AHR Disinformation Analyst
RE: [Repeater-Builder] 900 meg Spectra radio
On Sun, 28 Feb 2010, allan crites wrote: What really needs to happen is for someone to design a transistor or FET RF power doubler for all those 450 Mhz radios that will be coming or now surplus on the commercial market. Then amateur 900 MHz would boom. Don't ask me to do it, I don't have any time. WA9ZZU The problem isn't the radio, the problem is the ham. If it wasn't made for the amateur band and doesn't have buttons to push, most hams won't use it. When you start saying things about programming software and channelized and no repeaters in the area, well... the average ham just decides to find something else to play with. Hams don't work on radios any more. They buy them new and push buttons. If it doesn't have push buttons and can't be programmed using a user-friendly interface, most aren't interested -- even if it is the cheapest band to get into because the radio and antenna are surplus! Yaesu, ICOM, and Kenwood don't make rigs on that band, so they aren't interested. Whaddaya mean ya gotta modify the radio? I don't know about this modifying a commercial a radio business. I ain't never hear'd of a ham radio by Motorola. The doubler idea is nice, except that the vast majority of the radios that are already at 900MHz use 2.5KHz deviation, not 5.0KHz deviation (or 10KHz, which would be the result of doubling a 5KHz radio). -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Re: LOOONG audio runs
On Sun, 28 Feb 2010, Mike Morris WA6ILQ wrote: 2) the pair that was receiving the problem was a high impedance load or an unbalanced load (i.e. one side grounded). Use an ungrounded 600 ohm winding from a transformer on each end of each pair. The nominal impedance of a copper pair from CAT5 is 110-ohms, not 600. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Suggestions for signal generator?
On Sat, 27 Feb 2010, AJ wrote: Anyone have a suggestion for a simple 50 ohm signal generator? I have a number of VHF Phelps Dodge duplexers and several UHF flat pack duplexers I'd like to be able to test prior to sale and possibly rough tune for a few projects duing the waning weeks of winter. I realize a network analyzer would be the best case option for doing this sort of work; followed by possibly a service monitor and a spectrum analyzer with tracking generator. I currently have an HP spectrum analyzer available at work; unfortunately it did not come equiped with a tracking generator. It does have a current calibration; I'm guessing I could use it to determine the exact output from a signal generator and subsequently the insertion loss from the duplexer. You'd probably want to drive the VCO of the signal generator directly to make it sweep up, but if you don't have a good baseline on how it's power level varies over the range, you won't be able to compare with the antenna response. Something like an MFJ-259 attached to a sweep generator would probably do the job. Of course, the MFJ-259 doesn't have great frequency stability, but you're not staying in one place for very long. Then you can use the spectrum analyzer for what it does best. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] LOOONG audio runs
On Fri, 26 Feb 2010, JOHN MACKEY wrote: I have a odd situation where I need to run long audio cables between my repeater controller and two repeaters. In this case, the repeater controller will be connected to 2 repeaters in the same cabinette. The other two repeaters will connected thru about 140 feet of wiring to the other side of a building. I am thinking of using balanced audio wires for the long runs and using Henry Engineeering boxes to convert between balanced/un-balanced at each end. Anyone ever done long audio runs like this? Am I over engineering it and unbalanced will be good enough? unbal to bal is a good idea. It isn't over engineering as Motorola did this for years with radio accessories. And they only had to go 17 feet. Getting rid of common-mode interference (ground loops) is worth it. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] dual band convertacom
On Wed, 24 Feb 2010, hitekgearhead wrote: What I would like to do is parallel these two amps with some kind of switching/duplexer setup so that I could easily switch from VHF to UHF. My initial idea was to run an antenna switch from the convertacom to the amps so I can manually select which one the signal goes to. Then on the output side of the amps I thought about using an antenna duplexer on the output of the amps to feed the antenna. I was also thinking of running a switch to alternately select which amp was receiving DC power, but I don't know if that would be necessary. (Could I leave both amps powered on in this situation?) So, does this sound about right or am I going off the deep end? Buy two duplexers (diplexers) from some ham source, put one between the MTVA and the amps, and the other between the amps and the antenna. No switching needed. If one really wanted to get wonky, you'd put another MTVA in the car and use a linear dual-band HT amp, but you'd have to look at the third-order intercept points on a spectrum analyzer to make sure the amplifier doesn't create mixing products, and alter the drive level of the two HTs to make sure the amp doesn't go non-linear when trying to amplify 145MHz and 440MHz at the same time. -- Kris Kirby, KE4AHR Disinformation Analyst
RE: [Repeater-Builder] Re: DB-201 Measurements for 6 Meters?
On Mon, 22 Feb 2010, Jeff DePolo wrote: Kinda along the same lines as always make the cable from the connector on the transmitter to the connector on the duplexer an even half-wave. The reason for doing that is that if the duplexer presents a short-circuit, said short-circuit won't appear at antenna port. Given the range of most duplexers, it would be unlikely that the cavity would cause such a situation to exist unless it were struck by lightning. -- Kris Kirby, KE4AHR Disinformation Analyst
[Repeater-Builder] Mask filters?
In the commercial world of broadcasting, there is a hybrid filter used called a mask filter. The mask filter is two -90 degree hybrids, a dummy load, and a pair of bandpass cavities between them. They suppress sidebands and keep the TV transmitter's radiation within the 6MHz channel. Has anyone heard of a similar concept used for filtering amateur repeaters? -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Mask filters?
On Mon, 22 Feb 2010, IM Ashford wrote: These filters are constant impedance designs so the transmitters unwanted sideband power gets dumped into a load on the Hybrid port. This also helps with group delay at edges of the filtered response. ... cant see why a ham would make a filter with twice as many cavities than needed, just to keep SWR low out of band.. Perfectly matching your noise and reflected power to a dummy load, minimizing mixing and out of band signals. -- Kris Kirby, KE4AHR Disinformation Analyst
RE: [Repeater-Builder] Re: DB-201 Measurements for 6 Meters?
On Mon, 22 Feb 2010, Jeff DePolo wrote: On Mon, 22 Feb 2010, Jeff DePolo wrote: Kinda along the same lines as always make the cable from the connector on the transmitter to the connector on the duplexer an even half-wave. The reason for doing that is that if the duplexer presents a short-circuit, said short-circuit won't appear at antenna port. Uwhat? I was thinking quarter-waves. If you have a tee, connect the antenna at the center and a duplexer to either side using quarter-wave cables, the effect I noted should occur, minimizing losses. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Re: Unlawful in IL to Rebroadcast Public Safety Communications
On Sun, 21 Feb 2010, Greg Beat wrote: While the First Amendment upholds Freedom of Speech -- it does not uphold a person that yells Fire in a crowded theatre -- causing a panic and injury -- when there was no fire! w9gb Lenny Bruce made a comment about this, something to the effect of It's not OK to yell FIRE! in a theater, unless you're on stage... I actually hope this gets made law, and the FCC strikes it down. Then again, one wonders what happened to the FCC from the heydays of roving field agents checking broadcasters on a regular basis to today, where one may get by with a violation for several weeks without realizing it. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Unlawful in Il to Rebroadcast Public Safety Communications
On Thu, 18 Feb 2010, James Delancy wrote: Then it is a federal matter and not that I am much good with this legal stuff ... but no matter where you are, it is illegal to divulge what you hear to a 3rd party ... that would include a re-broadcast via IP or radio anyway?? So with that, aren't all the scanner sites illegal? Four points: 1) No station outside of Shortwave, TV, FM, or AM services are legally authorized to broadcast. 2) The Communications Act of 1934 and The Telecommunications Act of 1996 govern this. RF is the FCC's domains, unless someone really wants to rehash States Rights during this administration. 3) The use of the internet is governed by the FCC, through the divisions the telcos use, under the name they use: Common Carrier. 4) Interference with a common carrier is a FEDERAL offense, punishable by fine and/or jail time. On the point of #4, if a police officer pulls over a legally operated and authorized semi-trailer carrying a sealed load across state lines and tells the driver to break the seal on the trailer, that officer is interfering with interstate commerce and may be be arrested by the US Marshals. My advice? Don't test this law. If you do test this law and officers show up to arrest you, immediately call the US Marshals office. Oh -- get a good lawyer, and make him a rich man. And further -- it is impossible to broadcast over the internet or IP. There are mechanisms which work similar to the common-sense concept of broadcasting, but properly designed networks do not allow such packets to traverse the networks or the edges of the networks. Multicast, which is a broadcast like IP-based system has not been deployed on large scale basis by most providers. Like 99.999% of them. And they charge good money if your packets need to be in all places at one time -- that's X amount of bandwidth taken from ALL of thier pipes that service your points of interest. It's time for a repeal of that law, and a recall election to remove that member of the legislature from office. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Low voltage disconnect in Alberta winters and more
On Thu, 18 Feb 2010, Tony VE6MVP wrote: Also we're thinking of having a backup power generator being a lawn mower motor hooked up to an auto style alternator and a rioughly eight or ten hour fuel tank.If the batteries get too low then we'll just attempt to get into the site, fire up that home made generator and walk away. We'll make sure it looks like a rusty piece of garbage so no one who wanders by is likely to steal it. Any comments? Generators and fuel are a lot of trouble. (Apparently the snow drifts can get quite bad so we might need to borrow a snowmobile for the last 400 yards or so.) This is when you have to ask yourself: Is it really worth the hardship to keep this repeater on the air at this site? We're thinking of putting the batteries in a chest freezer disguised by thin plywood so it just looks like a box. We're told by the site owner that a fridge looks way too much like trailer trash so disguising it with wood should work.I'm thinking we would put the charge controller in there for a little heat and the dump load in winter Are we nutz? Have I asked some stupid questions? Yes, and no. For the former, you're in good company. The freezer idea isn't new; there's one repeater up somewhere in Canada that is near a rock peak mounted in a large freezer. It, along with the repeater trustees, were flown in with a helicopter. For your situation, it might be best to use a pair of freezers, and install a hasp and padlock on them. Put the batteries in one (or both) and the repeater in the other. If you can find self-resetting circuit breakers, I would use those for the batteries, and individually protect each battery from a common bus. This way, if you develop a shorted cell in one battery, or a dead-short across several or the battery itself, the problem becomes self-isolating. Of course, you have to be able to develop enough power from the other batteries to exceed the circuit breaker's trip rating. You'd be better off using fishing batteries than lawn garden batteries. Don't forget to make a gas collection/vent system using aquarium tubing or surgical tubing. Well, if you need a gas collection system, you don't have sealed lead acid (SLA) batteries, which means you're adding electrolyte or water a few times a year. SLA is the better way to go, but you have to watch the battery temperatures to prevent damage to the batteries during the warm months or when charging on a really good power day. Damage means the battery vents, and that's no good. So you need a good charge controller, and decent diversion load. I suppose if one was really inventive and handy with some metal tools, you could make a vertical rack and suspend a large weight from it. Then attach a screw/gear lift motor from the diversion system, and have a small, regulated generator from a different gear ratio making a few watts of power. 10,000 feet of wire-rope and an old oil well -- Kris Kirby, KE4AHR Disinformation Analyst
