You just got your GMRS license, now you want your own repeater?

[wayoverthere]

11 minutes ago, Sshannon said:

I probably could get away with driving a post, but we share it with a rancher who grazes his cattle there.  If something happened and he complained to the BLM we might lose access.  I’d rather not chance it.  Instead I thought I’d use the weight of the batteries to stabilize the antenna base.  As I learn more about antennas I might be forced to admit you’re right. If so I’ll contact the rancher and the BLM before driving a post.  We use aluminum 1010 rail for our launch rails and we have some tripod or quad pod bases for launch pads that I thought I might be able to repurpose as an antenna base, weighted down with the SLA batteries.

As an alternative to a post sticking up, what about driving a larger piece of pipe into the ground, so your "mast" can slide down into it rather than over it, while not leaving something sticking up that could be a hazard when it isn't being used. That might be a little easier sell than something sticking up, though then it's how to mark it in a non-hazardous way...flexible flag of some kind?

[Sshannon]

43 minutes ago, Lscott said:

I’ve given up on SLA batteries. Switched over to using LFP, lithium iron phosphate, types. A good source is at the link below. 
 

https://www.bioennopower.com

For solar charging in the field you need LFP specific charge controllers. I have several of the GV-5’s from this company.

https://sunforgellc.com/genasun/

 

Thanks for the info. I’ll look at those, but based on my anticipated usage, I doubt we’ll deplete the battery charge during a typical launch as it is.  

We’ve used SLA 12v x 7000 mAh batteries for 19 years for the launch system and I can count on one hand the number of times we’ve had a battery fail.  I recycled ten or so last year that were 18 years old, but continued working.  If I ever get through the big pile of batteries that’s in my shop I’ll be very eager to try whatever new technology is available. 

Edited December 14, 2021 by Sshannon
Added information

[Sshannon]

27 minutes ago, wayoverthere said:

As an alternative to a post sticking up, what about driving a larger piece of pipe into the ground, so your "mast" can slide down into it rather than over it, while not leaving something sticking up that could be a hazard when it isn't being used. That might be a little easier sell than something sticking up, though then it's how to mark it in a non-hazardous way...flexible flag of some kind?

That’s an idea.  An in-ground socket.  Maybe a flange at the top to make it easy to find.  I’d probably plug it so it doesn’t fill with dirt between launches. Thanks for the idea.

[WRFP399]

On 12/13/2021 at 7:49 PM, Sshannon said:

Very new guy here, but what I first noticed is the notion that a cheap repeater won’t do what a person wants, but that’s entirely based on an assumption of what that person wants, without ever asking.

So, here’s my use case:

I’m in an amateur rocketry club, launching from hilly land.  The hills make simplex communications impossible when we’re retrieving rockets, even though the range is always under five miles and usually within one mile.  However, there’s a tall hill to the east which is visible from most places.  I suspect that hill would make a good spot for a temporary repeater in a man portable can. Because it’s BLM property, nothing permanent can be erected.

The repeater is only needed one day per month for about 8 hours and total air time is probably under a half hour. There are no GMRS repeaters within maybe 100 miles.

This seems like something that the Retevis RT-97 might do well.  Because I would have to carry it to the top of the hill, it has to be something lightweight.  We may not drive off-road and no roads go to the top of that hill.

This would probably be paid for out of my own pocket.

Why wouldn’t something like the Retevis, a whip antenna, and a couple SLA batteries in a five gallon bucket be appropriate for my purposes?

Thanks for your help,

Noob Steve

WROM258

Sounds like a solar recharged RT97 w/ a simple N9TAX rollup antenna might work for you. Simple, small, portable, and little to no environment impact.

If you want a complete setup that can be carried in a large backpack:

A 30 watt solar panel can fit in a large backpack. A 30 watt panel and a 14 amp hour SLA battery seems to work well here in Alaska during the Spring/Summer/Fall Season but can't keep up during the cold winters with little sun. If you are not in an area that suffered from greatly reduced solar in the winter it would be a solid place to start.

Use some alum angle riveted to the back to mount the RT97 and a small solar controller directly to the back of the panel. You can attach the panel directly to a tree, place the SLA battery at the base, and hang the N9TAX in the tree itself.   I have posts in this forum about my setup and it might stir some ideas for you.

Is this some 100% Duty Cycle Commercial Grade Setup? Nope. But I get 20-30 miles out of mine to 5 watt handhelds and it works for us.
 

 

[Sshannon]

@WRFP399 That’s pretty slick.  Because I only need it once a month and during that time to listen for 7-8 hours at a time and possibly transmit for a total of (much) less than an hour, I probably wouldn’t even add the solar charger, at least initially.  I’ll look into the antenna (N9TAX) and I’ll gladly pore over your posts on battery life. Nothing beats empirical data!

Thanks!

Edited December 31, 2021 by Sshannon
Misspelled word “beast” instead of “least”

[gortex2]

Id grab the Laird GF4500 antenna and a 3' or so LMR style jumper. Heck 1/2" harline would be ideal. Think you;ll be happy with the FG4500. I run it on my Motorhome with the RT97 and it works great. I run about 12' of RG142.

 

[PACNWComms]

Recently I have mentioned to a few people that have gone down the GMRS license path, and recommended UHF GR1225 and GR300 Motorola desktop repeaters. Add in a decent antenna and an old GR series repeater can do very well, especially if you swap the old radio (M120 mobiles in my GR300) for something newer, like an XPR4550 Trbo radio stack. However, one person I made this recommendation to, ended up attaching a Cobra magnet mount antenna (as in 27 Mhz CB), can you say, convoy......

[quarterwave]

Just a note I thought of as I a looked at repeater updates this week... 

Whether you are an experienced radio guru, know enough to be dangerous. or a beginner, keep this in mind about repeaters: 

If you put up the highest gain antenna you can find, the biggest low loss transmission line and set your power out to get right on 50 out of the tx cans of the duplexer, and score a site 1500 feet AAT....the question is, how much do I need? 

If your best radio, or a user on your repeater, his best radio can get in from a maximum of, say 10 miles out, but your repeater can be heard for 50 miles...you might be overdoing it. Not only that, you might be keeping another GMRS-er from being able to use the frequency elsewhere if there is crowding, even if your tone is different. Remember, it's a user coordinated service, it's up to us to share. 

I once had a customer who had a 125 Watt VHF repeater, and on a good day his reliable coverage was 30 miles with mobiles, 40 miles if you were knowledgeable. You could hear it for 150 miles depending on where you were that far out. We turned it down to 75 watts and they never knew a difference. 

So, just my opinion, but I do believe in the ham theory that you only need as much power as it takes, no more. 

-

 

[n4gix]

12 minutes ago, quarterwave said:

If your best radio, or a user on your repeater, his best radio can get in from a maximum of, say 10 miles out, but your repeater can be heard for 50 miles...

That's known as a "gator mouth" repeater. Absolutely adjust ERP to match the receiver's ability.

On the other hand, given your hypothetical parameters, if the repeater can receive no more than 10 miles, something else is likely wrong!

[gortex2]

We used to balance all our repeaters in the LMR B&I world when i was with a shop. Exactly as you said. If all your portables are 4 watts and your antenna is on the building you operate in there is no reason to have a 100 MTR on the roof. In commercial many times we shared channels in the same city so balancing TX/RX was a way to eliminate the complaints of interfearance and hey my radios doesn't work ! 

 

[PACNWComms]

Talk In versus Talk Out range, something that does need to be emphasized at times. Kudos to those that did in this forum. 

I use a 25 Watt Spectra briefcase repeater when I head into parts unknown. With an antenna on a tripod about 30 feet above ground level usually gets me a few miles increased range, if on a hill, often ten or more. This works for my use case, as all other users are carrying four to five watt handhelds. Great portable repeaters, but getting harder to find. I use two deep cycle marine Optima batteries and often get an entire weeks of use before a charge.

[marcspaz]

1 hour ago, quarterwave said:

So, just my opinion, but I do believe in the ham theory that you only need as much power as it takes, no more.

 

I like the post... just a minor point of interest here.  It's not a Ham theory... the FCC rules say that amateur stations are limited to the least amount a power required for reliable communications, with maximum power limits.

 

47 CFR § 97.313 - Transmitter power standards.

(a) An amateur station must use the minimum transmitter power necessary to carry out the desired communications.

[quarterwave]

On 3/28/2022 at 8:54 PM, marcspaz said:

 

I like the post... just a minor point of interest here.  It's not a Ham theory... the FCC rules say that amateur stations are limited to the least amount a power required for reliable communications, with maximum power limits.

 

47 CFR § 97.313 - Transmitter power standards.

(a) An amateur station must use the minimum transmitter power necessary to carry out the desired communications.

Yep...point being just because it says 50 on the license doesn't mean you need it. You know. 

[WRQM273]

So, my question, as I am new just got a license and have been thinking about setting up a repeater for family use, I live nearly at the center point of most of my family. I have a few that are 5-10 miles in a few directions. My thought process is setting up a repeater at my house so that the 2 that are farthest apart, opposite directions from my location, can hear each other. Yes there is a local repeater, that I have already gotten permission to use, that I can connect everyone to. But it does get plenty of use, along with me wanting to be able to in the event of an emergency, pack up my system minus the cables and antenna, then deploy on some land somewhere else or use as a mobile repeater to keep everyone in communication with everyone else within my limited maybe 20 mile each direction bubble. Can this be accomplished with just basic handhelds on whatever this simplex is that I keep hearing about?

[BoxCar]

2 hours ago, WRQM273 said:

So, my question, as I am new just got a license and have been thinking about setting up a repeater for family use, I live nearly at the center point of most of my family. I have a few that are 5-10 miles in a few directions. My thought process is setting up a repeater at my house so that the 2 that are farthest apart, opposite directions from my location, can hear each other. Yes there is a local repeater, that I have already gotten permission to use, that I can connect everyone to. But it does get plenty of use, along with me wanting to be able to in the event of an emergency, pack up my system minus the cables and antenna, then deploy on some land somewhere else or use as a mobile repeater to keep everyone in communication with everyone else within my limited maybe 20 mile each direction bubble. Can this be accomplished with just basic handhelds on whatever this simplex is that I keep hearing about?

The quick answer: Yes, but not easily. Setting up a repeater takes more than just two radios and a couple wires. It's going to be much easier to use the existing repeater. Retivis sells a small repeater for around $400 that only requires an antenna and power.

[WRQM273]

2 hours ago, BoxCar said:

The quick answer: Yes, but not easily. Setting up a repeater takes more than just two radios and a couple wires. It's going to be much easier to use the existing repeater. Retivis sells a small repeater for around $400 that only requires an antenna and power.

I have been looking into using 2 KG-1000s, I already have 2 of them but one of them got fried when i first got it from a reverse polarity.. it would be something that i would prep for and buy part by part over some time. 

[WRTL671]

My only goal is to help spread the coverage of the linked nets. I want to make GMRS a huge hobby for people. Lots of dead spots in my areas still. Need more volunteer hobbyist. 

[KAF6045]

On 3/28/2022 at 8:54 PM, marcspaz said:

I like the post... just a minor point of interest here.  It's not a Ham theory... the FCC rules say that amateur stations are limited to the least amount a power required for reliable communications, with maximum power limits.

It is also not Amateur-only. Emphasis mine:

Quote

§ 95.367 Transmitting power.

For transmission of emergency messages, where operators of Personal Radio Services stations have the ability to select transmitting power levels, the highest transmitting power available may be used. In all other circumstances, the minimum amount of transmitting power necessary to carry out the desired communications must be used. See section 324 of the Communications Act (47 U.S.C. 324).

That's Part 95 A, which applies to all of: FRS, MURS, CB, GMRS, radio control, and a slew of other lesser known services

[quarterwave]

And while we are on the subject of Repeaters.... Why do people keep listing repeaters that do not exist? Is there some thrill? Aren't they sad or embarrassed when they have to explain it never existed? I don't get it. 

I've had a private repeater for years, people asked to use it right up until this Spring, when I made it public with new PL's and a refreshed listing. Now...summer activity time...not a peep. People still ask, even request permission even though they don't need it per the listing. Not a peep. 

If anyone is interested in a mint MTR2000, cabinet and Zetron panel.... she's probably going to be for sale soon. I'll throw in a supposedly good ASP805 & Clamps too (not mounted, currently stored in barn).

[WRUE648]

On 7/21/2021 at 7:09 PM, OffRoaderX said:

I didnt bother reading this whole thread, but allow me to share my (very recent) experience..

I recently built a repeater using two KG1000G's, a cheap mobile duplexer, a Tram 1486 on the roof and LMR400 coax - all the experts assured that my 'toy' would not work at all. Despite what all the experts predicted, not only did it work, it worked better than I expected, with a range of about 40 miles in each direction.

I have now got my hands on a (very) used Vertex VXR-7000 repeater - after paying for programming and re-tuning the internal duplexer, cost was about $650 - it DOES work better - less de-sense so it is noticeably more sensitive/able to receive signals that the KG1000g setup could not, and i'm getting a bit better range.. But the other big difference is that it is 'full duty cycle' so it can be used 24/7 - Wouxun says that the KG-1000Gs can also be used 24/7, but i'm not sure I believe that claim..

Was I happy with the KG1000G setup? YES!  Am I more happy with the "real" repeater?  Yes.

Do the math and do what works for you..Ignore the 'experts' as many dont seem to understand the difference between the term "will not work at all" and 'will not work perfectly/be the best" ...

Loved your YouTube series!! My interest is to follow your little 6 watts mobile unit for family camping!

[KB3HXA]

I have to disagree here. You can spend tens of thousands of dollars on a repeater if you want. That is no reflection on what it actually costs to have a repeater. I spent less than $600.00 putting up a repeater and that is if you count the cost of stuff I already had laying around.

GMRS coverage is sparse and limited to small cells. The more users who have them, the better coverage there is.

It is also clear that coryb27 is speaking about public repeaters. The vast majority of repeaters are for private use and less than 10 watts. My personal repeater has been up for 3 years before I expanded it and made it public.

Personally, I would not discourage a newcomer to learn how to establish a repeater. That is a learning process. If that is what gets people excited about the band then it should be encouraged.

I am a HAM as well but personal repeaters make no sense in HAM radio. With GMRS they are the foundation of wide are communications.

[WRVD377]

Well I am glad to read all of this.  Had I read this all first rather than all the web videos I may not have bought a mobile repeater. (Retevis 97) 5W real power, VSWR 1.00 - 1 and Opek 2401 "GMRS" only 25' max AGL, 30' cable run.  All I gained was end to end distance meaning 5 watt handheld to moving 5 watt handheld, if in two vehicles simplex was a no go over 1 ish miles in town. repeater made it 2.6 end to end.  I also gained 1.3 miles up a hill. Using google earth pro with as the bird flys and topo over map showing ground height point to point.  I kind of learned this with my Midland mxt500 to a Midland mxt 105 5 watt mobile 5 miles max with hills no repeaters.  After all my google earth pro messing around I learned that my valley, my friend's valley 30 miles away and the hills between made this undoable. So I am testing with the portable for local area, plan a $2K higher power repeater (40W) to expand that slightly from 2 to hopefully 5 miles excluding hills.  Upside, I may take the mobile to friends farm area on a hill to help cover wider area as a fixed temp repeater with solar power.

Google earth pro if used right will show you where you will fail if you are a newby.  Clearly I cannot put up a tower high enough to talk to my friend, unless I find someone willing to put a repeater up at a specific area.

Otherwise, I just wish to make a range for my kids.

Royce 

[Fernleaf]

If you have the KG-1000G radios, it’s not cheaper than buying the Retivis repeater, but at least these are 50 watt machines. For your family use, they probably do fine. I’m going to set them up to extend the range in my area as OffRoaderX did and run a test for range as well. Since it won’t be used 24/7, I won’t have to worry about duty cycle and overheating. 
 

It will be interesting to see what you come up with. 

[WRVD377]

On 12/9/2022 at 2:15 PM, Fernleaf said:

If you have the KG-1000G radios, it’s not cheaper than buying the Retivis repeater, but at least these are 50 watt machines. For your family use, they probably do fine. I’m going to set them up to extend the range in my area as OffRoaderX did and run a test for range as well. Since it won’t be used 24/7, I won’t have to worry about duty cycle and overheating. 
 

It will be interesting to see what you come up with. 

Hello FernLeaf,

I watched videos of two of those.  Looks simple enough.  However, I think I will buy the Bridgecom device. I have not read bad stuff about them except a few.

I did test my 15 Watt 275 in my truck and could trigger the Retevis (5W) repeater from 3.8 miles flat area with trees.  Up on the nearest hill North 2.3 miles.  So power and elevation both seem to make a difference even in a valley.  I'll have to see how far away my 50W MXT500 can still trigger the tiny repeater.

I can make the mast a few feet higher also, just seeing how far I can cover around the house so if I let the kids roam they could still reach me without a cell phone.

It is now for a little fun for me.

Thank you!

[gortex2]

Height is key. The taller your antenna the better.