Jump to content

WRKC935

Members
  • Posts

    678
  • Joined

  • Last visited

  • Days Won

    16

Everything posted by WRKC935

  1. We are trying. But it IS a work in progress. On a side note. Can pictured be posted via links here? I have tried to post images here that are on Flickr here and had no luck. If there is some secret to this would someone let me know what that is please. Plan is to archive the project here and being about to directly post pictures and not just links I believe would be beneficial.
  2. Na. screw it. Between you and the guy that said I need to get a part 90 frequency pair and run P25 with ASE256 and RAC to keep things private,,, I am in agreement. Why should I care about other license holders. And if I invest in a number of FB6 pairs, I can put up a commercial DMR system instead and sell time on it. Who has time for hobby and family radio users anyway. Thank you for helping me to see the error in my thought process. I will say that we need to quit hijacking this threat. So when a Mod see's all this,,,, please clear it out until it's back on topic.
  3. I don't have any interest in choosing who uses the repeaters. That's the point. If you are legally licensed, you can use any of them it will be ASK of those using them to use the lower frequency repeaters first if they aren't busy. When they are busy, they are free to use the higher frequency repeaters. Like I said, even semi-private is too strong of a term. But if you are thinking I shouldn't do it. Then maybe I will just skip it.
  4. Site is owned by the other guy involved with this. So it is privately held. The previous owner was in process of razing the site when it was purchased. They had not scheduled the explosives team to drop the tower and sold it to my buddy for the value of the land under it. His goal is to be strictly ham radio. There have been inquiries about space for rent by WISPs and a commercial broadcaster that wanted to put police scanners there for their news team. He was and still is adamant the site is not to be a business venture. If the site had been commercially viable he would not have been able to buy it anyway. As far as repairs. The building was a mess. Ther was nothing there in way of electric. The first order of business was to get a temp service set and get the tower light working. Then it was money hand over fist to rebuild. I would say with the generators, electrical, securing the site, camera system, and other expenses he spend 12K in addition to the purchase price. Thats not counting the taxes, insurance or electric bill.
  5. Private is a strong word. Not really private,,, more like here are TWO repeaters for the masses. Knock yourself out. Yes, they are free to use. Here are two other repeaters that when these two are busy, you are welcome to use... But try using the other ones first. Personally I feel it's better than putting up multiple repeaters on EVERY frequency, and charging money for getting access to said repeaters. Take a look over at the new tread about the tower, the GMRS project and what we are working with. It's not to limit access to anyone. It's to provide access to repeaters with decent coverage, that will be available at all times. Better yet, let me ask you this... Once you see my tower, and know what the coverage footprint is, you will want to put a repeater on it. Your Kenwood, or two Midlands with a back to back cable and a CW ID board. So YOUR call sign is on the repeater, and you have lots of coverage. And you are willing to share your repeater with other GMRS users by calling it an OPEN repeater. So what is the difference if it's My gear and my call sign on the repeater if YOU still have access and don't incur costs of renting a port on the combiner or antenna space rent for a fixed antenna on the tower?
  6. I have found if you want to 'scare' them. Get a government looking vehicle. Couple antenna's and dark tint. Get some cheezy sun glasses and park ACROSS the road from them and sit looking serious. Take some notes and pictures (don't really need the photos but use a real camera and not a cell phone. Don't answer any questions when they come over asking about what you are doing and just claim it's an ongoing investigation. And for God's sake... wear dress clothes, and maybe a tie. Try to look the part. People typically will revert to what they see on TV as being reality if they don't have first hand experience. Something as dumb as a notepad and a handheld radio you are "talking" into when you see someone doing dumbsh!t like tossing stuff in a dumpster will get them all worried. We laughed about that for hours. The property owner even came over and told us the next business day the guy had permission to use the dumpster. When we explained it to him, he laughed too. But the point is to look the part and seem important. People get all worried when they feel they are being watched. But be careful... some folks WILL get violent with any sort of provocation. So don't push, and always keep the vehicle pointed is a direction for easy egress (get away) from the location.
  7. Here is the new thread https://forums.mygmrs.com/topic/2326-site-buildout-on-the-monster/\ Sorry this got hijacked.
  8. Some have read the other post that I sort of hijacked with my crazy GMRS plans. Guessing some have questioned the validity, my ability, and said " cool story bro". Here is what we started with in the winter of 17. https://flic.kr/p/2hLHs8V To say it was a mess is an understatement. The previous owner had contracted crack heads to do the tear out. They took anything metal. They even took a door. Not to mention every bit of conduit. I had been in the site 6 months prior and everything that AT&T had there was still in the building. It took 3 very large roll off dumpsters to get it all out of there. So I went to work rewiring, reworking and rehabbing the building. At this point, we have a large AREDN (Amateur Radio Emergency Data Network) with access nodes on all four corners of the tower covering 900 2.4 and 5.8 There is a large ham packet switch network hub in place covering all bands including HF. And of course a GMRS repeater (soon to be more). Not to mention the ongoing projects. A Centracom Gold Elite console system. Several ham repeaters, DMR and analog. I semi serious HF station... More antenna's to be installed in the spring. Couple shots of the interior https://flic.kr/p/2khe2Ti https://flic.kr/p/2kjeWTE Now there was some discussion about my plans to put up 4 GMRS repeaters and how that was going to happen. Here is the 8 port combiner https://flic.kr/p/2kjeofT https://flic.kr/p/2kjaCPs Some of the repeaters https://flic.kr/p/2kjeWGT https://flic.kr/p/2kjeo64 The MTR on top is the current GMRS repeater we have on line. The XPR's in other photos are going to be used as well for this endeavor. Here is the Centracom CEB stack. This is a work in progress that will be interfacing to the control stations in the second photo and the repeaters as I get that fully programmed and running. https://flic.kr/p/2kjaCA1 https://flic.kr/p/2kjeo88 Up till now, it's all just in a block building. So here is the tower next to the block building https://flic.kr/p/2hLJtx7 And a couple photos of the firefighters training on the tower. We donate access for high angle and rope rescue to all fire departments in the area. https://flic.kr/p/2khdz69 https://www.flickr.com/gp/36646490@N05/hzD6f1 So that's what I am working with. It's been time consuming, but fun. And the best part is, since it's all private, I can do as much or as little as I feel like on any given day. Specifics on the tower. Height 239 feet to the lightning rod tip. 43 feet from leg to leg. Two decks on top, one is octagon. The lower is square. THe lower deck is 40 by 40 with 4 horns Upper deck we haven't measured, but it's smaller, has 2 horns. Since I always get ask about the horns. They are 12 foot wide and 15 feet tall at the apex of the top. Electrically they are a section of a 24 foot dish. Beam width is 1.5 degrees and the mathematical gain is just under 40 DB for 11 Ghz and 30 something for 6 Ghz. Feel free to ask questions.
  9. Got a question pertaining to what you wrote... Do you know how much a SINGLE repeater is to setup and operate correctly? It's out of the reach of most license holders. Which means you get what ever coverage you can get off putting an antenna on a pole next to your house, or maybe a small tower (50 or so feet). Other than the power increase from .5 to 50 watts what are you getting that you cant do with FRS? Now I am FULLY aware of the state coordination committee with respects to ham radio. Only difference is the ones around here end up getting letters from attorneys telling them to cease and desist when one of the guy's dies, and his wife is a ham and wanting to keep the repeater on the air, but the committee wants the pair for their own private use. And then you have the non-standard frequency repeaters that have been on the air since before there was such a thing as coordination that a parked in between two standard frequencies making BOTH unusable. Then you put up a repeater on a non-standard split, 147.415 / 147. 950 (closest used freq in the state was 147.300 / 900) and everyone gripes that it's a non standard split. Tons of fun. Yeah, I too have heard the comments about doing digital things with GMRS. Frankly I am against it 100% because the interference issues that it will create. The issues with users needing new radios that are digital. But as far as it not being a public service. Really? Explain the linked systems that exist that connect multiple states together on GMRS... How is this different?
  10. WRKC935

    GRMS or HAM

    Ham VS GMRS. That's gonna depend on what YOU want to do with the radio hobby. And the number of users in your area on GMRS and their willingness to talk to you. GMRS is VERY limited as opposed to ham radio. You have 8 repeater channels and 14 interstitial. Ham has BANDS of frequencies and a number of modes of operation. You can experiment in ham radio with any sort of communications technology... GMRS is wide band FM on UHF. That's all there is and there ain't no more. I am a communications hobbyist. In short, I like radio. I am a ham. I have a GMRS license (which I waited far to long to get) and I am a commercial radio tech as my chosen career path. GMRS is a PART of my hobby. But I can't build a GMRS radio,,, where I have built several ham radios. Mostly single frequency HF low power stuff, but I built it and communicated with it. The only person that will know if a ham ticket is the thing to get is you, all we can do is explain the differences.
  11. That is what the quantars and DIU-3000's are for ... but they only have DES in them so no super secret squirrel activity for the time being. A new GTR-8000, site controller and 7000 series console system is just not in the budget. Got to settle for Gold elite and Tensr channel banks to run the Roci Cori links to the house for the CIE's And yes,,, I am. It's in the works
  12. No,,, the stack is 7 feet tall will get pics today of building interior and whats going on.... I am guessing that if I explained it without pictures,,, everyone would call me a liar
  13. DB Spectra If I remember right.... can't remember the part number. It Is two 4 port units stacked on top each other... If you were around for the Motorola UHF SMR stuff, it's those. They made a kit for stacking the units and it was custom cut cables. You had to have certain ranges in each set of 4, meaning you couldn't spread 450 and 460 across the 8. You would put your 450's in one set of 4 and the other set got the 460's. Since these are gonna be 460 and 440, I am just going to put up a second transmit antenna and be done with it. It seems I can't post pictures in here, but I will get a couple and share links so you can see whats up. I realize that all this sounds like some hack's pipe dream. But a buddy of mine that spent WAY more money on tools and equipment setting his garage said to me the first time I walked in "My reality is better than most guys fantasy" Here's ONE shot of the interior of the building. https://flic.kr/p/2khe2Ti It's still a mess but it's a work in progress. Here is what we started with 2 years ago. https://flic.kr/p/2hLHs8V Keep in mind that two guys put this back together. Cleaned it, rewired it and continue to build it. I need to put up one more cable tray to the back of the building where all the combiners and VHF duplexers as well as the receive multicouplers will be located. Obviously you are aware that this type of gear takes up a good amount of space where VHF ham is concerned due to the need for the large cans for the .600 splits for the repeaters. At some point, I plan to try to cobble together a transmit combiner for VHF, but that is nothing that is on the short list of things to do. I have a line on a large amount of 6 and 8 inch copper hardline that I believe will work well for making cans out of and the rest is simple machining. Finger stock and some luck. Not trying to reinvent the wheel, just copy what others have done and do it cheaper than the 5 to 8 grand per port for the commercially available stuff. Once I am happy with the results I may send them out to be silver plated as I really don't know if I want to deal with the amount of acid required to submerge a 8 inch diameter 20 inch long copper tube in. But that's a bridge to cross later. As far as loss, Motorola was the ones that bought these originally. Meaning it was top of the line gear for the time. And while i don't doubt what you are saying, I have another one of these that is a 8 port combiner that I am putting 20 watts in and getting 9.5 out measured with an Anritsu 412 and a 30 db directional coupler which was verified against a R&S digital watt meter to verify the cable losses and coupler attenuation. I should probably start a different thread concerning the site and the progression.
  14. Ham VS GMRS. That's gonna depend on what YOU want to do with the radio hobby. And the number of users in your area on GMRS and their willingness to talk to you. GMRS is VERY limited as opposed to ham radio. You have 7 repeater channels and 14 interstitial. Ham had BANDS of frequencies and a number of modes of operation. You can experiment in ham radio with any sort of communications technology... GMRS is wide band FM on UHF. That's all there is and there ain't no more. I am a communications hobbyist. In short, I like radio. I am a ham. I have a GMRS license (which I waited far to long to get) and I am a commercial radio tech as my chosen career path. GMRS is a PART of my hobby. But I can't build a GMRS radio,,, where I have built several ham radios. Mostly single frequency HF low power stuff, but I built it and communicated with it. The only person that will know if a ham ticket is the thing to get is you, all we can do is explain the differences.
  15. Well, it seems that I may have not done my research before asking the question. The person in question and his network of 20 some repeaters may just be a pipe dream. Although registered on here. He has never posted. There have been others that have posted pertaining to his system and they have never heard it on the air. So he may be running something out of his garage or something or it may have been a pipe dream that never came to be. I am gonna move forward and will be on the air by the end of next week on .575 .625 .675 .725 (725 is currently on the air under the call sign of the tower owner and will remain there) For those in Central Ohio,,, .575 and .625 will be the two fully open repeaters with 141.3 PL. the repeater at .675 will be the roll over for those two and will have a 103.5 PL. As far as cost,,,, we already own the tower. So the electric bill, taxes, tower light (yep over 200 feet, gotta have it) and the like are already expenses. Not sure how this will effect the electric bill running the three aditional repeaters and the receive multicoupler. But I am not real concerned. Spring time will see a solar and wind charging system feeding the grid tied battery plant we already have, so that will address the better part of the electric bill I am hoping. Our belief since the purchase or the monster is we have it, we need to use it and let others enjoy it as well. https://flic.kr/p/2hLJtx7
  16. I have experienced a DB420 being used at too high of an elevation in Columbus, Oh. Commercial repeater owned by a TV station. Had repeater and antenna mounted at 750 foot on a work deck. Repeater would talk to Indiana with no problems. It however would not work at all within the 270 outer belt unless you were in the helicopter. Think of antenna gain from an omnidirectional antenna like this. The pattern of the antenna is like a doughnut. In order to get gain from it, you have to crush the doughnut. So as you compress the doughnut, and it spreads out (directional gain) the bottom and teh top get pushed together. You need to be IN the doughnut in order to talk and hear the signal. If you raise the bottom of the doughnut above the ground, then you no longer have coverage. Now, on to solar powered repeaters. Honestly the repeater / duplexer / antenna is the easy part. The amount of storage and charge capability of the panels, specifically what amount of each that you need, are the difficult part. And this all hinges around the load. The receive / not transmitting part is easy to figure out... you put a current meter on the radio and see what it's drawing at rest. Then you get a reading on what it's drawing when transmitting. The hard part is figuring out how much transmitting the repeater will be doing in a 24 hour period. How many amps for how many hours. And you need to be reasonable with transmitter power as well. Is this going to be a public access repeater? How many folks do you expect to be on it and for what length of time. How many hours are there is a day during the winter where you are wanting to put the repeater? Does this location have good views of the Southern sky? The reason for the winter day time is summer is easy. Days are longer than the night and A couple 300 watt panels and a car battery will keep you going. The winter, snow fall on the panels, possible lack of access (you did say mountain) is where you need to closely consider storage and charge capability. If you are drawing 2000 watts or power out of the battery system per day and due to day length and other factors can only put 1500 watts of power back into the batteries during the course of a day, your battery plant will go dead. Couple things to know. First is output power (RF) requirements aren't near what you think you need. (Most will want 50 watts) Case in point. I have a system I manage that has 420's for transmit and receive through a combiner. The antenna's are at 400 for receive and 380 for transmit. Base stations are set at 20 watts out. They will not turn down further. So 20 watts out the back, into an 8 port combiner that drops 3 db off the signal. Then through 600 feet of 7/8 cable with a loss of 2.65 db per 100 feet. Calculator says that's 13.25 db of loss. Now that is in addition to the 3 db from the combiner. So 16.25 db of loss figured against 20 watts. If we convert 20 watts to dbm... we get 43.0103 dbm. Subtract 13.25 db and you get 29.76 dbm. Now switch that back to watts and it's a antenna melting 912mW or milliwatts. Not even 1 watt at the base of the antenna and the thing talks from Columbus to London Ohio. that's 40 some miles. Granted the antenna has some gain. But the system is still an alligator,,, big mouth, out talks it's receive abilities. Point is that if you run 2 watts in to a db420 or even a 408 and have a duplexer with only 1 db or so of insert loss and a 30 foot run of cable, and not 500 feet, then you are gonna still talk at least as far as you hear. Once you are getting serious about this endeavor, go download and figure out a freeware software called Radiomobile. It's a coverage mapping software. Do coverage testings with low power levels of 30 or 33 dbm (1 or 2 watts) Once you see that going from 30 dbm to 40 dbm or 50 dbm (1 watt to 10 watts to 100 watts) you will see that the coverage doesn't drastically change. Of course the 100 watts is purely for seeing the difference as we are limited to 50 watts out on a repeater. There is some change, to be sure, but it's not a 10 mile circle vs a 100 mile circle. And since the software takes into account frequency and topographical data for the area around the transmitter site, you may find that only 1 watt will sufficiently cover the area you wish to serve and beyond that the topography of the land stops the signal anyway. Lots of math involved in a solar setup to be sure. But if you are serious, I would be looking for a lower powered repeater that runs on 12 volts and not 24 and begin searching out solar panels. And be aware that panels will show the MAX output in direct sunlight. Meaning that a 300 watt panel is only going to do 300 watts on a cloudless day at high noon when it's being fully hit by the sun directly and not at an angle. What ever it says on the panel figure 1/4 to 1/2 will be the average output throughout the course of the day.
  17. OK, so lets bring something else into the mix. And I am not saying I want to do this necessarily, but it interests me. I saw the stuff about linking, and found that there are NO repeaters in Ohio that are linked machines. While I think I know what is going on with linking, I probably only understand half of it. Is there a document that explains the specifics of this? Are the links nailed up or are they user / repeater owner controllable? Is this a good option for a large coverage repeater or is it preferred for smaller coverage footprints? Thought process is this. We have had discussions internally (me and tower owner) and with a group of guys in Mt Vernon and Newark. As mentioned, I have a 4 port combiner that is technically 8 ports. The plan was to use 4 ports for GMRS and 4 ports for ham repeaters. The 4 ham would be a basic conventional, a DMR-MARC, a P-25 and probably a second DMR machine that would have both Talk paths as local only and have the other Linked repeater with BOTH paths as wide area or some combination of the two. The idea being if the wide area is in use on a specific TG then another machine would allow additional conversations on other TG's. The current systems all have the same TG's routed to them,,, so if one is active they all are typically. So the other 4 ports being GMRS, means it would just make sense to put up 4 GMRS repeaters, And the two main line public machines,,, one might get linked to the Midwest system. Would be interested in having discussions with whoever on this and getting some information.
  18. Best to grab a map of Ohio. Find Johnstown. It is North East of Columbus between Columbus and Mt Vernon. That is the RF site. Now, looking west of columbus on I-70 you will see St Rt 42 cross I-70. It gets noisy there on a mobile back to the repeater. Now looking North from Johnstown. The last of the solid signal goes into Marysville, and a little burg called Beliview. Or Bellville.. it's north on St Rt 13 north of Mt Vernon. East, find Zanesville. It's good to there, starts getting noisy past that. Lastly is South,,,, we are currently limited to the south due to a 12 foot wide 15 foot tall Microwave horn being to the South of the antenna on the tower. It talks as far as the Northern edge of Lancaster. Lancaster is further limited by geography. But it doesn't even hill top real well down there. North East and West we get about 50 miles. And yes we are running legal power limits, mobile radio is an XPR with a Unity gain antenna (cheap Motorola NMO mount wire antenna) Repeater is a 40 watt MTR2K with a Cellwave duplexer and a DB420 at 230 feet Pretty standard stuff. Truth is that the site is almost too good for a FB2 commercial shared frequency. Even power and height limited, the site talks for miles. We have talked to ham repeaters that are VHF, using a DB404 (yes a UHF antenna) in Cleveland, Findlay, Dayton and Cincinnati that is mounted at 110 foot on the North face of the tower. And we did verify that the repeaters we were talking on were in those locations. Granted, they were on tall towers as well (taller than ours) But the path loss still would have been pretty high... And we were using some Icom or Kenwood ham radio, 50 ish watts out. Nothing crazy like running a 250 watt amp.
  19. Thank you sir for the clarification
  20. Ok. Let me define semi private. The area we are in is typically a pl code of 141.3. So the public repeaters would be on that pl. The semi private ones would be a dpl that would be shared if someone ask with the understanding that the public repeaters be used first so the liading on the semi private units would stay quiet until the system loading required them to be used. By others. As far as expense. Yes, none of this stuff is cheap. But if equipment is no longer supported or broken many commercial entities will request equipment be replaced due to their need for very stable systems and upgrades from analog to DMR. And of course the dreaded XPR 8300 repeaters that would burn up with the slightest provocation. And those are NOT factory repairable any more. If you ship one to the factory for repair it will be sent back untouched. Can they be fixed. Yes. But you need some specialized gear to get it done successfully. I have a stack of them that were dumpster bound and parts to facilitate the repairs. The rest of it is all cast offs, site clean outs of abandoned equipment and ham fest purchases. Someone mentioned a licensed LMR freq. I have considered that. But there are two issues with it. First is those are suppose to be for business use. Second is cost. And as funny as this sounds, the 500 bucks for the repeater pair would be more than I have invested in ALL the gear for a single repeater duplexer and antenna system. I am going the route of gmrs because I can throw radios in the family vehicles and hand everyone a portable and be able to maintain communications without everyone needing a ham license and it not cost me for a frequency that the fcc will most likely not issue anyway
  21. No, not wanting to put two repeaters up on same frequency. Wanting to put up 4 repeaters on 4 different pairs. Two being semi-private, the other two being free full access. I do love that ya'll have taken and classified the CCR's and even given them an abbreviation. And for clarification, when I say transmit combiner, think duplexer that allows 4 repeaters to transmit on one antenna. And the repeaters I have are MTR's , XPR's and Kenwoods. So no junk. So my issue is this. I don't want to interfere with anyone purposely. BUT, If I want to put up a repeater, or several and a person has taken ALL the pairs up with pay repeaters (didn't realize that you could do that on GMRS) I am not really concerned that I am going to interfere with his pay units if I am putting up FREE access units. But I am curious about what others are going to think about all that. Keep in mind that we did have a group find the current repeater that the site owner put up and were using it. And they contacted us. We explained that it was a sort of private machine, but we were in process of putting up public machines, and I am retuning their duplexer so they can get on the air. They were ecstatic that they would have access to a repeater on our tower with the coverage it provides and not just working off a 10 foot pole bolted to a house. And yes, if I had dumped a ton of money into repeaters and others came in and parked on the pairs I was using, I wouldn't be happy either... But if I am CHARGING for access to those repeaters, and the other guy has his own gear and wants to do his own thing and not PAY for access to my stuff (still not sure how you can charge for access, this ain't commercial radio), then why should I be mad about it either. And as it's been mentioned before. Commercial LMR (licensed business band radio) share pairs with different PL's and all is good, but they have licensed operating area's designated on their license (so many kilometers from the transmitter) which GMRS does not.
  22. Does the requirement to ID still exist if you are on your owned repeater and it is IDing via Morse Code every 10 minutes?
  23. Well, I have to ask the question. I see a lot of the required expense and such for setting up a repeater system. So lets take this to the next level and say that I already HAVE it... ALL of it. A 4 port transmit combiner, 4 repeaters, a 240 foot tower with the proper antennas (DB420 with 7/8 cable on top for receive and a DB408 for transmit 30 feet below it). Receive multicoupler... you know,, ALL of it. At a site with a battery plant, and a generator for power backup. Look my HAM call sign up on QRZ to see the HAM owned tower. So here's MY problem. There is in what my established coverage area, which covers most all of central Ohio, some folks that have pay repeaters on the air on EVERY GMRS frequency. I don't do the PAY thing. The discussions with the site owner have been a 2 and 2 setup. 2 machines that would be semi-private. For his family and my family to use for personal traffic and two repeaters that would be full public access with their PL's posted here and available for ANY GMRS license holder. The site is a partnership between the two of us where his funding and my knowledge have merged to create what we hope to be a spectacular Ham radio communications facility. This will hopefully be a "Big Gun" HF station with several non-club affiliated repeaters on all common amateur bands and GMRS with a coverage footprint covering out 3 counties in all directions. So far we know the UHF coverage runs from Madison to Muskingum East to West and from Marion to Fairfield (south currently poses issues due to some rather LARGE microwave horns) North to South. My concern is that there is NO possible way that if I stand up these repeaters that the pay site guy will not be mad as I will provide FREE coverage on at least TWO of his frequencies that he has put up that are small profile machines. And probably more than that as there are 8 total frequencies and he has over 15 repeaters listed on this site. I really don't want to irritate anyone... But I also can't find enough motivation to NOT put these repeaters on the air because someone else feels the need to turn their GMRS license to a money making endeavor. So what's the opinion on this endeavor. Or a better statement is, I am GOING to do this. Unless someone has are REALLY compelling reason I shouldn't. But I am looking to hear if anyone has a compelling reason.
  24. First off, I HATE that this is my first post on here. I would much rather it been the HI. I'm Keith and I'm a radioholic. I can say that due to getting the bug at the age of about 8 or 10 with CB. Been an ham for over 20 years and a commercial radio tech for over 10 years. Enough with the introduction. While I can see the draw to doing DMR on GMRS, I will give a friendly warning about getting what you wish for. I mentioned the commercial radio tech thing. And I will comment a bit on first hand experience with DMR and analog on the same frequencies. First off is DMR modulation causes the signal to carry for distances that are surprising. We have two customers that are 4 counties away. Both were analog at one point and they never once had interference issues with each other yet they happened to share 2 frequencies. One was a 5 site analog simulcast system. Meaning 5 radio towers in different areas of the county, linked together and transmitting at the same time on the same frequency. Other customer had 4 different repeater sites and 4 different frequencies. So then it was decided that the second customer with 4 repeater sites needed to be DMR IP Site connect ( the technology that the ham radio DMR systems are linked with. And it was not EVER right, and they were BOTH interfering with each other, immediately. The DMR was breaking into the analog audio for the analog user, so they were hearing the DMR in places. And the fact that there was signal from the analog getting into the DMR radios for customer B... they would just hear nothing. So here's my point. We have 8 repeater pairs to work with nation wide. Customer B's DMR repeater that was interfering with Customer A was a 3 db gain antenna on a roof top that was MAYBE 60 feet in the air with a 40 watt radio that was cut back to 20 watts. Customer A's simulcast system was installed with the antennas below 120 feet to purposely reduce the coverage of the sites because by design you don't want a lot of overlap in an analog simulcast radio system. Switching from analog to DMR as far as the heard signal, at 50 watts, would be like an analog signal at 300 watts. And that pulsing type of modulation, busts right through the noise floor and is heard by analog receivers very well, and better than the analog signal. So be careful what you wish for. When this happens, and it probably will at some point. The repeater that you sometimes hear two counties over, will be busting into your analog radio when you get into the fringe of your repeater coverage area and REDUCE your effective coverage area by as much as a third, with NOTHING that can be done about it. I was told that the FCC even considered reducing the power levels for repeaters in the public safety bands to 10 watts or less for DMR users. For those of you that are in the business. The company I work for is the one that bought BACK a DMR radio system (Customer B's). That fact is pretty well known in the commercial radio community. And if you have heard about it, please refrain from mentioning who I work for or the customers out of respect. I personally would never even consider running a DMR repeater on GMRS unless it was a collaborative effort and it was only on one frequency. And that it was FREE to assess for all GMRS license holders. Don't get me wrong. DMR is great. It would bring in TDMA to GMRS and give license holders twice as many talk paths as we have. Simplify linking and create the ability to have Group Call's (talk groups... I know,,, I do the Motorola thing). But the fact that it would create a ton of harmful interference for those folks that are just wanting to do the analog thing. And enjoy the license and its benefits without needing to completely replace their radio systems, I can't in good conscience advocate for the change. Just my two cents.
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use and Guidelines.