Radioguy7268

No problems here - your answer did include some helpful information. It's just that anyone reading through the responses would wonder why a GMRS forum wasn't leading with a GMRS solution to a GMRS question! I'd also say that 4-5 watts UHF GMRS portables would be the equal or better compared to 2 watts MURS in most real world scenarios requiring signal penetration in and out of buildings and vehicles. Plus, if you start with some decent UHF GMRS portables, you've got the option to program them to a repeater. There's simply no option for MURS bubble pack radios to work on a VHF repeater.

Guy comes to myGMRS.com - asks about a GMRS solution, and the first 2 answers he gets suggest MURS & CB? C'mon folks. This is why people get frustrated with asking for advice online. YES! GMRS is a good solution for what you're looking to do. You might be able to get 1 mile or so out of UHF handheld portables - but a simple GMRS repeater at roof level will probably get you between 2 and 5 miles without even trying. Now - you're going to need to do some reading and educate yourself to a certain level if you want to do this on your own. Otherwise, open up your wallet & call the local two-way radio shop, and purchase their parts & experience. https://forums.mygmrs.com/topic/1402-you-just-got-your-gmrs-license-now-you-want-your-own-repeater/

Part 90 software only difficult to obtain if you're trying to get it both cheap AND legal. If you don't mind spending the money, Kenwood is easy to get from any Dealer, and Motorola isn't always cheap or easy, but if you can spend the time to set up an MOL account (Motorola On Line) it's easy enough to obtain. Otherwise, Ebay has about 100 listings on any given day for copied software burned onto discs - and there are sites out there on the interwebs that offer free downloads - although it's not always current/up to date versions & it's nearly guaranteed to be stolen/unlicensed.

The only Part 90 radios that I'm aware of that used Sideband was some Aerotron stuff in the '80's that worked on certain odd narrowband splinter frequencies in the VHF band. SEA (Datamarine) took that same tact and used ACSB for the 220 MHz band in the late 90's. I'm not aware of any manufacturer who tried any AM Sideband for UHF frequencies with Part 90 equipment. I played around a little with the SEA stuff and thought it was decent for what it was. They used a pilot tone in the middle of each narrow channel to try to keep everything centered on frequency. I remember that certain voices (higher pitched young women) would drop out certain sounds - I specifically remember that "Six" and "Seven" would cause problems. Put a middle aged male with a raspy voice on the mic, and it came through loud and clear with every test count. Ran our techs around in circles until we figured out what was going on - the higher pitched voices were running right in the middle of the notch for the pilot tone!

Without trying to go too far off track - what I've got (as an example for the OP) is the RMN5127A mic. It's got the 4 way navigation key - but no display. Those run @ $100+ (new) as an add-on option to the XPR mobile. You would probably also need an optional Mic cord extension to remote mount the radio under a seat & not need to stretch the std. mic cord, or just have a convenient place to plug/unplug the mic cord if you want a "hideaway" option. What I've got looks like the attached photo: There's another member on here - Cory, who has the HHC mic option for the XPR5550e.

The Motorola XPR5550 & 5550"e" version both have a Handheld mic option with the capability to switch channels from the mic and use DTMF for control. You can remote the transceiver and run an extension cable for the mic. It's also got voice announcement, so you don't need to look at the large (color) display for 95% of normal functions. It's not a Part 95 radio though, it's Part 90 commercial, and will also work on DMR. A brand new unit will run you 3 to 4 times what a Midland would cost. Used units are more reasonable, especially for the older Non-e XPR550. In fact, I've got one of the XPR5550 models with the advanced mic option that I previously used on GMRS. Color display, voice announcement, and only driven on Sundays. Guaranteed working. PM me if interested.

This is why FCC Type Acceptance is a GMRS requirement. "Build your own repeater" is a HAM project, not a GMRS project.

Your choice of 47 C.F.R. § 2.1 says: "a radiocommunication service between specified fixed points, only." Are those "specified fixed points" geographical points on a map? Or are we back to the definition without a defined meaning? I don't agree with Fixed Stations being limited to telemetry or Linking 2 (or more) repeaters. I don't see that conflation contained within Part 95.

I don't believe that Part 95 properly defines the term "Fixed Station" - which leaves the meaning open to interpretation. To my mind, a Fixed Station operates on the High side of a Frequency Pair - which would be the 467.xxxx frequencies. In other words, they would be transmitting on the repeater inputs -and potentially causing interference if they operated at high power with a high gain directional antenna. Base Stations transmit on the lower side of the Frequency Pair - ie: the 462.xxxx repeater outputs. At least, those are my definitions. The FCC has left us to figure out which ones make sense absent any Part 95 definitions or rulings.

Commercial tower sites tend to be expensive. Most towers are owned by the 3 or 4 major tower players, and they generally deal with cellular and other wireless carriers who will sign 20+ year leases with $1500+ per month. I've heard of premier location tower sites with rents over $4000 per month. Now, a cellular carrier wants premier tower space, and they're hanging massive amounts of equipment (3 or 4 antennas per "sector" - with Remote Radio heads on at least 2 or 3 of those antennas, and 3 sectors for a standard triangular array). You need a footprint that's about 1/10th of what a cellular carrier wants, but the national tower companies don't generally respond to offers of a month to month or annual lease with rents of $150. There's a ton of high rise hotels out on Daytona beach, and I'm sure a few of them have space on the rooftops. Avoid the ones that already have cellular antennas on top, as there's likely a management company involved who is already in control of everything that's going up on the roof. I would try to find one of the less prominent hotels that's still locally owned and operated, and see if you can't work out a deal for rooftop space. You could probably swing a deal for annual rent (paid up front) that wouldn't break the budget, and you also wouldn't need to worry about hiring a tower climbing crew, or paying for 200+ feet of high end Heliax coax cable. Find a maintenance guy at one of those hotels and offer to bring him lunch one day, it might make it easier to get up onto the roof. I'd also tell you that a 50 foot HAAT out on the Florida coast is nothing to sneeze at. You won't cover the entire county, but you should get a good 5 to 10 mile radius without even trying.

Tripod? Use a string & a decent sized rock to hoist your roll up slim Jim up to the highest branch your throwing arm can reach.

MURS is for Multi-Use. Business or Individual, pleasure or purpose. I'd agree that there's no need to run 35 watts (70 watts ERP!) for an on-site system talking back with 4 watt portable radios - but the FCC allows it. I'd also just about guarantee that they're not actually running 35 watts output on the rinky-dink Mall repeater that they're probably using - most small repeaters burn up quickly under a heavy load running that kind of power. 20 watts is probably closer to what's actually being run. I've got Business customers in Construction and Contracting who run MURS radios, mainly because it's quick and easy, with no need to bother trying to license individual site locations. VHF does have a few specific "itinerant" frequencies (151.505 comes to mind) but if you listen in on those channels - you find some of the largest construction firms in the area have camped out on those channels and effectively run off any other co-channel users. They're also using those licensed VHF frequencies with high power mobiles (I've seen more than a few 110 watt Maratracs running Narrowband kits) - so MURS still gives them a place to run a low power portable for job-site use. Quick and easy.

Half the time I see people blaming a "bad duplexer" - it turns out to be the junk cables connecting the repeater to the duplexer. You should be using a good quality double shielded cable like RG400 with the correct ends (no adapters!). Type N is the preferred connector, but if your repeater or duplexer has different connectors, you need to work with those. Try someone like these guys - avoid the cheap "tin" or nickel plated connectors - there's a few USA based sellers with similar products: https://www.ebay.com/itm/6-10-RG400-M17-N-Male-Clamp-Jumper-Silver-coated-RF-cable-USA/131269263466

If the reason that most people get the Midland is because they want an "out of the box, Part 95 legal radio" - then opening up the radio to a 25 kHz bandwidth (which the Midland isn't type accepted for) kind of kills the whole rational they started with. Might as well have gotten something like a part 90 radio that actually did 25 kHz right from the start, and saved the time & trouble. It would be just as legal (maybe more), half the price, and work twice as well.

Back in the late 90's - Kenwood offered ( I never actually sold one, but saw a few units being demo'd) a radio that transmitted pictures via UHF frequencies. I believe it was one like this: http://www.acicommpact.com/kenwood/kvt10.html I remember that it was fairly slow data speeds for transferring a low resolution picture - but I can't remember exactly how slow it was. I do remember making a comment during the presentation that I could probably snap a Polaroid & walk it over to the intended recipient before the Kenwood camera would have made half it's transfer - and not tie up the channel during the whole picture transmission. But yeah, in today's world, it seems every phone has a camera, and plenty of the lower end CCR's have options like a flashlight and an FM radio receiver built into them. If you had the ability to transfer picture/video over WiFi it might serve some purpose.

While the information above is useful - there is no correct answer to whether the FCC considers GMRS to be wideband or narrowband. The FCC simply does not care which bandwidth you use, either one is acceptable to them. Most high profile repeater systems do use wideband - for the increased performance noted above. There are valid reasons why people might want to use narrowband, mainly due to available equipment or interference.

I'd be concerned with anyone who let a repeater go out the door & didn't check the duplexer the first time. If he didn't get it right then, what's the chances he's going to get it right this time? It sounds like you bought it from the seller as a working package. Before you send it back - make sure you've got the cables hooked up correctly - the High side should be to the Receiver, low side for the Transmit. I've seen too many jumpers crossed up not to ask.

Sounds like you're in a good position to move forward. It's definitely worth it to get that DB4076 tuned up to your frequencies, and just add a tuned bandpass cavity to the receive side - effectively giving you 3 cans on the receive side, which should get you something north of 85dB for isolation and tamp down any noise before heading into the Preamp. I like the Advanced Receiver Research P460VDG GaAs-FET pre-amp for a budget conscious GMRS build. The specs are great, and the price isn't bad. Make sure you get the unit that covers the 460 MHz band. Noise floor is below 1dB - and effective gain is +12dB. You might even need to pad that down a little depending on your repeater's own internals. I've never messed with any of the Icom series of Repeaters, so no idea how good that FR-4000 is. I'll just about guarantee you that a "hot" pre-amp with 20dB or more gain will overload the repeater's front end. I've heard of some guys liking the Mini-Circuits pre-amps for amateur stuff - but the advertised noise floor of 2.5 dB scares me off. I've never actually had one on the bench to try it out. Maybe someone else here has. The best pre-amps I ever touched were made by Angle Linear - but apparently they closed up shop around 2017 or so. Sinclair used to use the Angle Linear inside all of their high end Multicouplers - which I took as pretty high praise, since apparently Sinclair didn't think they could make one on their own any better. Lightning is the #1 killer of pre-amps. Make sure you're bonded and grounded. Read up on Motorola's R56 standards if you haven't studied them before. Good luck with it.

Receiver pre-amps are NOT magic. In many cases, they'll actually make a system worse. Signal needs to be greater than noise. The benefit of a pre-amp is in raising the strength of the desired signal above the noise floor. If you raise the noise floor at the same time that you're raising the signal, you've done nothing to improve the Signal to Noise ratio. You need to have proper front end filtering in place before you even consider a pre-amp. If you're using a 'flat pack' compact mobile duplexer, you're not doing yourself any good to add a pre-amp. If you've already spent the money to hang a quality antenna that's up above the tree line, and you're running a high quality bandpass/band reject duplexer, you might see some improvement by adding a pre-amp. Might. We have no idea what your system is currently, or how it's performing. Do you have the tools and knowledge to measure receive sensitivity of your repeater? Do you have the tools and knowledge to measure de-sense?

Motorola MOL dealer website still shows them as being available - Dealer cost is north of $150. Adding on a 15-25% nut for profit margin, plus shipping, and you're probably going to pay @ $200 or more. I don't see any of them currently available on Ebay. Are you looking to buy new? Or hoping to find someone giving one away?

Again - Part 90 is NOT controlled by any of the amateur Frequency Coordinators. You're going to have to check with someone else. There are certain particulars that involve areas of operation that get within a certain distance of the Canadian borders. I'm not up in that area, so I've never really paid much attention to the Border rules.

I'm not sure how close you are to Canada - but just wanted to make sure I'm clear. Business frequencies under Part 90 do not share any frequencies with amateur radio. Your comment about 440 and 222 makes me wonder if you checked availability with an amateur Frequency Coordinator. There is no "waiting list" in the Business bands for Part 90 UHF.

I think you've got the concept - run under Part 90 as an FB6/IG - but you need to certify that you're going to provide communications service to "Part 90 eligibles" - which means US Citizens and US Companies that would be otherwise eligible under Part 90. Technically - you could also provide FB6 Private Carrier service to Public Safety entities - or a non-profit Town Watch group. I'm not the law, and I'm not the FCC, but I've done this type of licensing for other entities. You are the one who needs to certify what you are planning to do, but I'm not aware of any requirement to "show your books" to the FCC to prove that you're running a for-profit business, or any site inspections. You will need to run Part 90 type accepted equipment, and you will need to certify buildout/construction within 1 year of your License being granted by the FCC. Judging by your GMRS license, you're located in a fairly populated area, so finding a decently clear frequency pair might be a bit of a challenge in the Part 90 spectrum. If you've already got a 60 foot mast, try to monitor some frequencies and see if you can identify any open frequency pairs in the area. Used to be that some of the older 451.8xxx pairs were clean, but most communications companies have snatched those up - at least in my area. I'd try looking up someone like FIT (Forest Industries Telecommunications) or EWA (Enterprise Wireless Assocation). They'll walk you through the steps. I find FIT to be a little more personable - but EWA is very professional & capable. Up front cost isn't cheap to get the 10 year FB6 license & coordination - expect to see something around $700, but it's still pennies per day. If you tell them you're looking for an FB6 UHF repeater pair with DMR/Trbo emissions, you'll be off to the races.

I've currently got 45 P1225's (mix of 2ch & 16ch) and over 20 CP200's in my rental fleet. Then there's the mix of 36 VHF and 36 UHF Vertex VX & EVX portables - not to mention all the Trbo DMR radios. I think I'm set. Some folks think I'm just sick.

That's a pretty good price on the CP200's - especially for working units in decent shape - with the charger. You might also mention that the P1225's are Part95 type accepted - one of the few Motorola portable radios available for "legal" GMRS use.