New GMRS user looking for guidance for a specific setup

[davidbeis]

Good afternoon all! I've lurked on RadioReference for years as a reader and scanner junkie only, and am finally diving into the radio family! This is a long post, but I like to be as thorough as I can be, as I know first-hand how frustrating it is to spend time answering someone's question only to find out there was pertinent information they left out.

I'm working on learning what I need to know to pass the tech ham license, but in the meantime I'm working with my church to develop a "CERT" team specific to our church and as part of that we want to put in place a way to communicate reliably among ourselves should the need arise. In light of that need, and after doing some research, it seems to me that GMRS is my best bet for being able to communicate across our general area without everyone having to get a ham license. FRS will certainly not suffice, and it seems CB is likely not a good option, either.

I've just paid for my GMRS license and I'm seeing that I should probably expect my call sign to come over in the next 24 hours or so, which is exciting! It's definitely doable for each family unit in our church's CERT team to get a GMRS license, so I'm planning to build our comms around that platform.

We're in the suburbs of Tampa, Florida, so while we do have a good bit of home/business/tree interference with line of sight, we don't have mountains and valleys to be concerned with (and we also don't have mountains to help with antenna height).

I'd like to set up a repeater at our church property which will allow us to hit up to 25-30 miles in any direction, and am looking for recommendations for the repeater unit and antenna as well as mobile and handheld units that are likely to be able to hit that repeater from up to 25-30 miles. We might be interested in having some "fixed" mobile or base units at far-flung member's homes that would act as further repeaters, if that's possible.

Ideally I'd like to be at or under $150/unit for mobile and at or under $100 for handheld units. I don't have a budget in mind for the repeater system mainly cause I don't know enough to know how much it's likely to cost, but the lower the better.

Among our group we have a lot of really good technical knowledge, so purchasing radios that require programming as opposed to pre-programmed GMRS dedicated units isn't an issue.

Since I'm personally pursuing my Ham license, I'm also interested in radios that might possibly work for GMRS use but that would also cover the ham bands for me in the future. Unlike some other newbie posters here, I have actually read CFR parts 95 and 97 as relate to GMRS and Amateur radio, and I understand that not all amateur radios are Part 95 certified, but I'm not necessarily concerned about purchasing something for my own use that carries Part 95 certification as long as it doesn't exceed the power output limitations, though I recognize that doing so isn't technically legal. For the other members of our team who are only going to be interested in GMRS, purchasing something that is Part 95 certified is probably best.

I appreciate any tips and direction not only on specific equipment for our needs, but also on how to set up a repeater system. Incidentally, myGMRS.com shows two other repeaters active in our area, and if it's possible to work with those owners to incorporate them into a wider net to save on setup cost, I'm interested in that as well. I understand I'd need to track down and contact the owners directly for permission, more looking for guidance on the technical side of it here.

Many thanks in advance!

 

[prcguy]

The only real problem I see is achieving a 25-30mi range in the flatlands of Tampa. With a repeater operating at the maximum allowed power of 50 watts, your range will be mostly determined by antenna height and to a lesser extent antenna gain. How high can you get an antenna up?

As an example of range I've had a GMRS repeater operating with a 10dBd gain antenna and very low feedline loss with the tip of the antenna about 45ft in the air with the building near sea level and reliable range to hand helds was just a couple of miles at best. That could go further in some directions but not reliably due to buildings and houses. Distance to a 50 watt mobile with good antenna varied from 5 miles to maybe 25 miles depending on direction and how much noise we were willing to put up with.

I currently have a couple of UHF repeaters on a hill about 350ft above sea level and hand held coverage out over flat unobstructed land is ok out to 15 miles or so with mobiles working out to 50 miles in some directions. Antenna gain here is probably around 6-7dBd.

For repeaters I would highly recommend a used Motorola Quantar, its probably the finest repeater you can ever afford and I've purchased several UHF 110 watt versions in the $600-$650 range used. That and a good duplexer (about $300-400 tuned) and really good antenna fed with the appropriate size Heliax cable will give you similar or better performance to your local police radio system. Programming for a Quantar is very easy and once tuned up for GMRS you can change to any GMRS frequency, change PL/DPL tones and it has a built in community tone panel so you can assign multiple PLs for different users.

 

[mmckenna]

I'd like to set up a repeater at our church property which will allow us to hit up to 25-30 miles in any direction, and am looking for recommendations for the repeater unit and antenna as well as mobile and handheld units that are likely to be able to hit that repeater from up to 25-30 miles. We might be interested in having some "fixed" mobile or base units at far-flung member's homes that would act as further repeaters, if that's possible.

25-30 miles of coverage is going to require some altitude, something you are in short supply of in Florida.

To get that sort of coverage from a mobile in a car or a hand held radio, your repeater antenna will need to be up about 400+ feet. You can check this yourself using a "distance to horizon" calculator online.

400 feet of tower is going to be -expensive- as in several hundred thousand dollars.

If there are towers nearby, you can lease space on them, but it will not be cheap.

For a reliable repeater, and all the stuff that you need to make it work:
Duplexer
Lightning suppressors
Intermod panel
Power supply
battery backup
coaxial cable (at 400 feet, you are going to need expensive cable, as in several dollars per foot)
antenna
as well as installation
-You are probably looking at $50K without tower or tower leases.

Ideally I'd like to be at or under $150/unit for mobile and at or under $100 for handheld units. I don't have a budget in mind for the repeater system mainly cause I don't know enough to know how much it's likely to cost, but the lower the better.

That's in the "used equipment" range.
You can find portables for $100, but 25 miles of range out of a portable sitting in someones house is not realistic.
Any used portable radio you buy is going to need a trip to the shop for alignment if you want it to be reliable, and that can run $100/hour
New battery will be required, used radios usually do not come with new ones. And then there are expendable items, like antennas that get abused.

Mobile radios will cost more, still need a trip to the shop if you want them to be reliable, and if you want them to work well, they need to have a proper antenna install on the vehicle. If you want to use them as base stations, you'll need to figure in around $50 or more for a good 12 volt power supply. They'll also need an antenna mounted up on the roof, figure $200 or so for antenna, coax, lightning suppressors, etc.

Not trying to discourage you, but your budget is way too low for what you want to do.

Among our group we have a lot of really good technical knowledge, so purchasing radios that require programming as opposed to pre-programmed GMRS dedicated units isn't an issue.

Programming is easy, and some used radio dealers will do it for you for free.
What you need is like I said above, if you are budgeting for used radios, you need to expect they'll be out of alignment and won't work well. Service monitors to do the alignment can run in the $40,000 range, so they are not something that people just have sitting around. They also require a lot of knowledge to use.

Since I'm personally pursuing my Ham license, I'm also interested in radios that might possibly work for GMRS use but that would also cover the ham bands for me in the future. Unlike some other newbie posters here, I have actually read CFR parts 95 and 97 as relate to GMRS and Amateur radio, and I understand that not all amateur radios are Part 95 certified, but I'm not necessarily concerned about purchasing something for my own use that carries Part 95 certification as long as it doesn't exceed the power output limitations, though I recognize that doing so isn't technically legal. For the other members of our team who are only going to be interested in GMRS, purchasing something that is Part 95 certified is probably best.

Your choice, but I'd recommend not advertising it.
It's not -just- the power levels you need to be concerned about. There are other technical requirements.

I appreciate any tips and direction not only on specific equipment for our needs, but also on how to set up a repeater system. Incidentally, myGMRS.com shows two other repeaters active in our area, and if it's possible to work with those owners to incorporate them into a wider net to save on setup cost, I'm interested in that as well. I understand I'd need to track down and contact the owners directly for permission, more looking for guidance on the technical side of it here.

Many thanks in advance!

You'd do better contacting those repeater owners and see if they'll work with you on this. Putting up your own repeater and expecting 25-30 miles of coverage is not easy or cheap. It's a huge and costly undertaking. It requires test equipment and a lot of knowledge to do right. Buying random parts off the internet and relying on a hobby website for setup instructions is a recipe for failure.
Again, not trying to discourage you, just trying to help you manage your expectations. From what I've read, your expectations are not realistic unless you have a several hundred thousand dollars to throw at this.

 

[davidbeis]

Definitely appreciate all the input, everyone! I see I still have a lot to learn

So now I'm perhaps back to looking into encouraging the rest of our team to pursue their technician licenses as well, as we certainly don't have that kind of money available to work with!

Back to the study book for me, and many thanks for all the input!

 

[KC5AKB]

What is CERT? - Florida CERT Association Inc.
I would not rule out the GMRS for local coms
With each other as some of your group might not want to study for a ham lic

 

[chief21]

I would not rule out the GMRS for local coms

@davidbeis I agree with KC5AKB. Just because you can't afford a repeater, your group could still utilize simplex GMRS channels with base stations (up to 50 watts, max), mobile radios (50 watts, max) and handhelds (for close-in comms). In Florida, I would expect that a good base station with a quality, reasonably-high antenna would have some decent range - especially if communicating with a mobile radio. As long as the group purchases "repeater-capable" radios initially, you might be able to work out repeater coverage at some future date.

 

[prcguy]

Not counting the tower, you can get a first class repeater system with repeater, duplexer, antenna and a moderate run of feedline for well under $2,500. That could be a used Motorola Quantar repeater, a good used BpBr duplexer, new Stationmaster antenna and 50 to 100ft of used 7/8" Heliax with connectors. There is lots of surplus commercial equipment out there cheap including ready to go service monitors for well under $1k like a used IFR 1200S or similar.

In the last few days I just got another UHF Quantar for $650 shipped, a high end PD-526 duplexer in the $150 range (bought that awhile back) and a local ham had 50ft of 7/8" Heliax with connectors for $50 so I got it. There is $850 spent so far and its all tuned up on GMRS and running right now into an existing antenna. You can do the same for similar prices and last I checked a new 10dB Stationmaster was around $1,100 or so plus shipping.

The challenge is not the cost of equipment but finding a high building to put it on and someone competent (and free) to align everything and install it to code.

Definitely appreciate all the input, everyone! I see I still have a lot to learn

So now I'm perhaps back to looking into encouraging the rest of our team to pursue their technician licenses as well, as we certainly don't have that kind of money available to work with!

Back to the study book for me, and many thanks for all the input!