quarterwave

Yes, once you find your way around M equipment, like I did working for them in the early 90's, its is cool to see what you can get into. Our shop built alot of interesting things back then. I run a pair of M208's as a small repeater, I have it set for about 15 watts, and it works just fine. Celwave mobile duplexer and a MRE1032 RA_1 interface. I used the interface to get the audio adjustment and drop out delay. I also keep a couple of my own cables around to make a quick repeater if I have to. My main machine is a 100 watt 100% duty cycle MTR2000 turned down to 50 watts....with a Zetron 37. Love that thing.

Appreciate the counter points. I wasn't suggesting the R100 was not a good unit, it was good for what it was built for, which was not to be a 100% duty cycle heavy duty repeater. We sold alot of them when I worked for M, and they generally were great. I did see some melted down because the customer needed a MSR2000 or MSF but didn't want to spend the money. I would hate to see someone buy one that may essentially be salvage, and may not be working....but buying one from a seller that can test, and would take it back if it wasn't what he said it was, would be better. Especially if you are are just-getting-started radio guy. I would disagree a bit on the Radius and Maxtrac....I have seen many a small repeater made from them, and they are a reliable, well made mobile. I have some that are 20+ years old and work just like new. I do understand that everyone's experience will vary, we each like what we like.

If no duplexer, then yes, you must have vertical and/or horizontal antenna separation. Not always easy to do, or do right. That R100 looks ok, but you never know if it works and for how long, I am always wary of a reseller like that ("I bought it from XXX or an auction....was in service, untested, not tested, etc.") It is usually best to buy from someone who can test it (beyond plugging it in!) and at least for frequency, power out, and audio, which doesn't require a radio shop if a guy knows what he is doing. Also, on something as old as a R100 (they started making those in the late 80's and stopped in the early 90's) you want to be sure someone can program it. It takes a cable (or cable and RIB) and a PC that can run DOS, as well as a copy of the R100 software. So, not to discourage anyone from buying an R100, but I don't want anyone to buy a boat anchor either. Sometimes you can find repeaters on eBay that guy's build them selves, and while they might not be able to warrant the equipment, at least the put it together and generally had some means of testing it. If worse comes to worse, a simple controller from MRE1032 like http://www.ebay.com/itm/RA-1-Repeater-Adaptor-Motorola-GM300-CDM-1250-RICK-/350465888363 and then a couple of M120, Gm300, Motorola Radius or Maxtrac radios with 16 pin connectors will work fine. I have one of those I built right now. All you need is a mobile duplexer off Ebay and then get the radios programmed and the duplexer tuned and you are ready to roll.

Welcome. If you are still talking about a simplex repeater (simplexer, parrott, etc) you don't need to separate the antennae at all, since neither receives and transmits at the same time, and in the case of a simplex setup...you would only need 1 radio, as it is store and forward. These projects are cool, a guy has to touch and see this stuff, get a feel for how it really works. I would ask what the terrain is, seems like 180 acres would be easy to cover with just portables and no repeater. I have used them on my family farm for years. The down side of the simplex repeater setup like that is durability. The TX radio is working twice as hard, carrying transmissions from both sides of the conversation, plus you have to wait for your message to repeat, and then the other guy talks, and his repeats. Make for a slow conversation. They have their uses, so it's not all bad. I made a "heavy duty" one once using a 40 watt mobile, a PC, custom interface, and Echo Station software. Still have the parts, but don't use it any more. If coverage is the real issue, I would lean towards a 10-25 watt repeater with a duplexer. It's just cleaner, easier and more reliable in the long run. But, by all means, if you have the means and desire to "tinker" like most of us, don't be discouraged from building a simplex machine, best way to learn is try, and try again.

Well...Micor was getting old when I was working for M and Motrac was ancient! Heck...MSR was current but on the way out at that time. Anyone remember the difference between Motrac and Motran?

I've spent a lot of money while daydreaming....

I have built more than one repeater from a couple of Motorola Radius or Maxtrac mobiles. The best cables I have found are from MRE1032 on ebay. The simple one has audio level control and optional delay. I have made my own cable also, it's easy. I actually used a couple of Maxtrac's and a cable I made up in 10 minutes back about 20 years ago when I was working for M and our local city service departments' GE VHF repeater went kaboom on a summer day. Hooked the mobiles up to their duplexer, and made them a temporary 20 watt repeater. They actually wanted to keep it...I think it worked better than the old GE. I have seen the old "Industrial" MSF5000 repeaters...big cabinet, all the regular heavy duty internals...and a 6 watt PA.

Gotcha. Yes, if you were using the internet for back haul, you would certainly need something to re-time it all. Fiber or T1 would be ok, but not internet.

I agree. Although, they do seperately mention "interconnection" which is specifically phone patch. I think for GMRS, poor mans trunking would be the way to go for someone who wants to play. Multiple repeaters, different locations on same freqs with different input PL's. I have seen this done with radios that scan and use last channel talkback...so it, for the most, part channel steered for you. But even doing it manually, could be ok. The system I have in mind that a fire department uses, they just announce what "tower" they are on.

Yes, it is kind of a self solving issue, since most individual GMRS operators are not going to go to the lengths, especially financially, to set up this elaborate of a system. However, there is some unclear definition to the ancient rules concerning "wireline control link". In the subpart that says you cannot connect to the PTSN (dial up phone system) it does say the exception is wireline control, and mentions part 95.127 which is not listed with the other sules on the FCC site at all. I did find it in a separate PDF, but part of one of the paragraphs in truncated in the FCC's own document, so who knows... I remember this terminology used in commercial part 90 years ago, and what it was written to mean was you could not use your radio, whereas you had the use of a telephone, wireline intercom, order wire, etc, readily available to give the same message over, and you should not do both. I am guessing this had something to do with air time, or controlling unnecessary transmissions for preservation of spectrum availability. All in all, it boils down to theory, as who would really go to the trouble. In the end, what might make more sense for the adventuresome operator, is what a few county organizations I have seen do when they didn't have funding for voting or elaborate systems, and that is to simply install multiple single site repeaters with different input tones, but the same output tone, all on the same freq. Then, you just steer it by switching the programmed channels in your radio according to which site you can hit, and since you can normally hear more that you can hit, you could communicate with someone when each of you were using a different site.

Just to chime in on... "A GPS is also used to keep the voter receiver audio streams synchronized in order to avoid issues with network latency"...GPS is used for TX on the simulcast, it is not used on the receivers, as only the best audio is voted. I am very familiar with a couple of these systems. One in my area that is UHF uses 5 sites, 4 outlying, 1 central (hub). Each outlying site is a MTR2000 repeater which has it's TX and RX "separated". The same is true for the central site, there is just more equipment there. Each receiver listens on the same input freq and pl. Audio is sent to the hub site via leased lines where it goes into the voter, along with the RX audio from the central site, which is local to the voter, of course. The voter decides which of up to 5 audio signals is best, and locks in that one (I can't remember how often it re-samples, but it does). From there, TX audio is sent to the central repeater TX and the 4 outlying repeaters via an RF link that is about 10 watts, has yagi's pointing 4 directions. Audio is received at the sites, synced to GPS, delayed if necessary, and the transmitted from all 5 sites at once. The result is massive coverage. The voting can be bypassed with a channel that is programmed in the mobiles/portables which carries a different input PL, and is locally hardwired to trigger just the central local TX if activated. It's a phase 1 fail-safe so to speak. The central site also has a backup repeater and antenna which is kept disconnected from power and Tline, and only plugged in if needed. This is to keep it safe from lightning damage, etc. It has yet a third input PL. This agency also has a secondary single site repeater on standby at another site, on a totally different freq. The voting system is 453 with 465 for link outs. It has worked well for 16+ years. I wish the users knew more about their equipment, and they would keep up monthly maintenance to balance line levels, etc...but like most public agencies, money can be an issue. So I have seen the links done both ways, wireline or RF, or a combination as above. I am the admin for my companies system. I used to work in radio, so I get to be the guy. I took our voting system back to single site. We had a main site where the TX/RX was, and then 2 other RX only sites, which came back to the voter on wireline. The voter was mainly added for some data terminal project they tried to do in the early 2000's and gave up on, which also made everyone stop using the radios because there was now data on the channel all day, so people turned them down and forgot about them. The company also bought everyone a cell phone. Since they only added the additional RX sites to get better data signals (which is harder than analog voice) over the voice channel, and we were having issues keeping the lines balanced and voter working, I had it removed. Now that I have a stand alone MTR2000 again, the system works great, all the stray, forgotten about radios with data boxes that went on aimlessly squaking day in, day out for years while no one paid attention are gone. When I took it on in 2012 it was to reorganize it, re-license and narrow band. Now, about half the fleet has radios again, more will get them when new trucks come in to replace older ones. They still have cell phones, of course, but now they have radios that will make use of the repeater, and simplex for back up, in case they need it, or just for quick coordination in the field. We have 2 bases with 6-7 remotes too. The system is VHF on an exclusive channel, with a wide split, licensed for 350 watts, 500 Erp. We owned the tower until this year, and it is a nice high profile mountain top site. The RX antenna is at 270 feet, and the TX is at 180. I run it at 100 watts with no duplexer. 6+ MHz split. We used to have a filter on the TX site, but it was stealing 30% of the power, so I took it off. My M shop checked it all out...no de-sense. We have a 75 Mile license, but this thing can be heard 150 miles. There is no way we would get the same license with the same specs applying today, so I told them never to let it go. We use talkaround and 2 Itinerants as well, and I put 5 weather channels in the CDM mobiles. Sorry for the long story telling, but I wanted to share some insight, and I know I like reading about whats out there. I know these are not GMRS, but the examples lend themselves to the original questions.

I'll ditto on the tuning. I have a set of older Motorola style cans, 2 RX, 1 TX that I had tuned up on the main freq I use by my buddy when he still worked at M a few years ago. I use them in my MTR2000 machine. I have a small cellwave that was tuned for .700 at one time, and I have tweaked on it a time or two. I can "tune" it the hard way if I need to...bird power meter, and a TX I can reduce to almost no power to check the desense. Works good enough. I have it running 10w on .650 right now. You can do split antennae, I used to have a setup with the Rx separated 30 feet vertical and about 75 horizontal from the Tx. (Rx on a house, Tx on a barn, wireline between them). https://www.google.com/search?q=chart+for+antenna+separation&tbm=isch&tbo=u&source=univ&sa=X&ei=p5kCVOerFouVgwTt_4IY&ved=0CCQQsAQ&biw=1280&bih=649#facrc=_&imgdii=_&imgrc=0LkFtTJ5j4lp_M%253A%3BE6aFCo_TFpkO5M%3Bhttp%253A%252F%252Fwww.repeater-builder.com%252Fantenna%252Fimages%252Fvertsep.jpg%3Bhttp%253A%252F%252Fwww.repeater-builder.com%252Fantenna%252Fseparation.html%3B671%3B543

There are a couple other new ones up in that region too, glad to see the interest and growth.

I used to hear a guy who had a vox activated intercom on GMRS freqs sitting beside his scanner. I think he was trying to use it be able to hear his scanner somewhere else in the house, didn't realize it could be heard further away. It didn't last long, as you could always hear personal stuff being discussed too...I think he would forget to turn the vox off. I guessed it was a .5 to 1 watt, something like the ones Audiovox made. I was speculating that I was within a half mile of him. If you are getting a good signal, odds are someone is doing it intentionally, people wanting to do "neat" stuff all time, and either don't care it is not legal, or ignorant to the rules.

I tinkered with this last year. It's kind of neat, but doesn't seem "reliable" (of course it is free...so one cannot expect commercial grade), it seemed to drop out and disconnect whenever it wanted. Tried it on 2 PC's on different networks, and on my smartphone. Looks like everyone that joins makes their own channel, but not a great way to really figure out what is what. I was interested in using it as a link for: 1. Pushing my scanner audio to it to create a private stream for mobile use on my phone. or 2. Interfacing it with a UHF portable so I could use my smartphone to link to my PC/UHF and it would work my repeater. Tried 1, wasn't consistent. Didn't get around to #2.

At 200 you need FAA, 199 you don't. There are considerations in the direct flight path of any airport. City ordinance or neighborhood assn may apply locally. I'm no use on the document...but I don't think a contractor is liable to the city if the permit is in your name anyway. There are probably trees, power poles and chimney's higher than 30 feet if they look around. At the new radio shop, when I worked there (a long time ago) we put up a 50 footer, in the city, a guy from the city showed up, with his big boy pants on, and told me we could not put it up. I asked him to leave the property before I removed him, and if he could stand behind what he was saying to come back with the PD and a court order. Funny...he never came back. I had already consulted the city engineer and there was no issue. Wait...I was multi-tasking....see if this helps... http://www.faa.gov/documentLibrary/media/form/faa7460_1.pdf

Is that confusion I smell?

In the United States, the Multi-Use Radio Service (MURS) is an unlicensed two-way radio service similar to Citizens Band (CB). Established by the U.S. Federal Communications Commission in the fall of 2000, MURS created a radio service allowing for unlicensed (Part 95) operation, with a power limit of 2 watts. The FCC formally defines MURS as "a private, two-way, short-distance voice or data communications service for personal or business activities of the general public." MURS stations may not be connected to the public telephone network, may not be used for store and forward operations, and radio repeaters are not permitted. Industry Canada (IC) established a five year transition plan, which will permit the use of MURS in Canada starting June 2014.[1] IC has not yet published rules for MURS, other than frequency limits.

No, I'm afraid it's not "all fine". Follow the rules. I have read a couple of your posts, are you here to participate or instigate? Sounds very negative to me. I think I can speak for all members in saying we welcome participants....not problems. Let's don't be antagonistic...or maybe this isn't the site for you. And furthermore...a 300 watt repeater has no better usable range than a 50 watt repeater if the receive isn't enhanced. 4 watts from a portable still only goes so far to reach a repeater....300 watts is just "broadcasting" and is likely hurting the receive side more unless using high dollar cans, pre filters/selectors, etc. Moderator - if I am being too forward with our new member here, please delete. Just calling it as I see it, and don't want something getting out of hand.

I would not recommend using a repeater ID if anyone beyond you and your kin are using the repeater. As I stated earlier, mine ID's, but only a couple people who my license covers use it. It certainly points the finger at you if someone is doing something wrong. Let the operators ID themselves, and if you need a "beacon" (which is probably discouraged, but I it know why you would use, as I have too) use a controller with a voice announcment, or setup a control station with one. I have the ability to use EchoStation if I need to .

On the system I admin, our VHF repeater performance is likely degraded some due to Narrow Band, but we are not really noticing. The system has always been over-built (that is a Positive!) with a 75 mira license and it's good for 300 Watts (500 ERP) on a repeater that is on an awesome site. Our split is also 8 Mhz...so it's a great performing setup. We only run 100watts at the antenna...haven't needed to up it. I have seen less range out of our mobiles on simplex channels, we use 2 freqs for site work, portables and truck to truck in transit. I would put usable range down by up to 30%.

You know, it is somewhat amazing to me that Radio people, and the agencies never think about this stuff, and accommodate it. However, a salesman will typically miss it....in my 25 years experience in radio. I think it is simply irresponsible and dangerous for any public safety or public service system to operate without a simplex option. A local (to me) PD and FD went to statewide trunked system a while back, and I am told they have no simplex. The existing VHF and UHF radio (which were in good working order) were zealously ripped out of the cars and trucks in favor of the new "toys"...which work great, but offer no back up to trunked or failsoft repeater operation. I am told they don't even have NPSPAC 800 simplex programmed. Leaving the radios that were narrowband capable (which were most of them) in the vehicles, and using it for back up would have been wise. The FD kept it's VHF repeater and simulcasts dispatches on it, but that's about it. The PD kept their UHF control base....but only to talk to the service department whom they gave the repeater and radios to. They don't even have the ability to use VHF interops from anything they own. 25 years ago every Sheriff's car, PD car, and HP car had VHF with at least 2 common VHF channels and bases all over our state. That was interops. Now they have pretend interops....patching a trunk talk group into another system and fighting with it and the training to get it to work. It's a shame. Sorry that was all off topic.

Hello, as a former Shack geek in my college days, I was the deferred to as the "expert" on just about everything most of the time, unfortunately. On one hand it was because I probably did know the answer, on the other, the evening shift guys I worked with were "gravy" guys....they only wanted the easy sales, and were too lazy to work for it. Guess thats how I ended up a keyholder too! 1. I would look for a Kenwood or Motorola dealer if you are serious about building a small business system. There has to be someone near you somewhere. 2. You can look here: http://home.provide.net/~prsg/ 3. GMRS is for personal use, not business use. The exception is "family" businesses, such as farms, etc where all radios are operated by family members. You could technically license all individuals for GMRS and then all be legal to talk to each other...but that is impractical to do, and maintain with employees. You need to use MURS (2 watt VHF) for business....or license it with a coordinated business frequency. You can use a repeater then as well (MURS you cannot). Enjoy GMRS for personal recreational, etc use...but it's not meant for business, nor is it legal for that. I do know some businesses that run on FRS just to use CHEAP radios....but a real business deserves better than FRS. Look into real radios in Part 90 service. http://www.ancom.org/ - Motorola https://www.google.com/maps/place/Co-Meg+Sales/@43.85278,-92.488236,17z/data=!3m1!4b1!4m2!3m1!1s0x0:0x166aeba8d4da6cd0 - Kenwood

Renewals are $200?

I agree, they have played that game forever. Everyone's mileage will vary, usually you can find a shop that will still do them, since the shops are not owned by M. If not, there is always some good ol' boy that has a copy of the s/w he downloaded from a foreign website. LOL.