Budget friendly repeater for private use

[WB9YBM]

I am more than interested in hearing you out on building my own repeater with your ideas! I am here for knowledge!

I've put together a repeater with a couple of spare mobile rigs, taking a signal from the LED that lights when the radio receives a signal, and with a buffer transistor (NPN in open collector, grounded emitter configuration, 4.7K resistor on the base) to toggle the second radio into transmit. Since a lot of radios have a short burst of noise when the transceiver toggles from transmit back to receive, I've added a key-up delay. I also added a "hang" timer so the transmitter stays in transmit for about 1 second so it doesn't "chatter" when a weak receive signals drops in and out of the receiver, like this:

and ground unused inputs of gates, like this:


If you use two transceivers in the same band, you'll need duplexers; in my case (in the ham bands) I used a good frequency separation (like 144MH & 220 MHz).

If the repeater's located where you can supervise it, that should be enough. If it's remote, though, I wired up a 3-minute time-out timer on eavh PTT line, like this:

(again grounding inputs of unused gates).

Please let me know if you have any questions.

 

[mmckenna]

I agree with prcguy.

$10/month for repeater access isn't a lot of money for some, but may be a hard stretch for others.
A repeater capable of coverage reaching out 8-9 miles may be possible, but without knowing the exact terrain/locations you are dealing with, no one could really tell you for sure that it's going to work. If you are on a high hill, then probably. If it's flatlands, 50 feet isn't going to get you very far.

So, $120/year for repeater access per user.
I'd say have them put that $120 bucks into a good antenna on their roof and some good coax down to their radio. See how that works.

If a repeater is still required, you won't need to invest as much if they already have decent antennas on their end.

$1000 repeater isn't going to get you very far unless you are buying all used stuff, and even then, that's requires a lot of knowledge and test equipment to set up properly.

 

[rescue161]

You can send me a message with your address, or the address of the repeater site, and I'll run a coverage plot for you with different heights. That will give you a very good idea of what you'd really need to get the results that you desire.

 

[srbecker58]

I've put together a repeater with a couple of spare mobile rigs, taking a signal from the LED that lights when the radio receives a signal, and with a buffer transistor (NPN in open collector, grounded emitter configuration, 4.7K resistor on the base) to toggle the second radio into transmit. Since a lot of radios have a short burst of noise when the transceiver toggles from transmit back to receive, I've added a key-up delay. I also added a "hang" timer so the transmitter stays in transmit for about 1 second so it doesn't "chatter" when a weak receive signals drops in and out of the receiver, like this:
View attachment 103159
and ground unused inputs of gates, like this:
View attachment 103160

If you use two transceivers in the same band, you'll need duplexers; in my case (in the ham bands) I used a good frequency separation (like 144MH & 220 MHz).

If the repeater's located where you can supervise it, that should be enough. If it's remote, though, I wired up a 3-minute time-out timer on eavh PTT line, like this:
View attachment 103161
(again grounding inputs of unused gates).

Please let me know if you have any questions.

This is just insane! You are a much smarter man than I lol. I thank you for that information though, if/when I ever need it, this will be extremely helpful!!!!!!

 

[WB9YBM]

This is just insane! You are a much smarter man than I lol. I thank you for that information though, if/when I ever need it, this will be extremely helpful!!!!!!

Just years of simple tinkering finally paying off. I've got to admit: seeing someone else getting use out of my ideas can be more fun than using the stuff for myself.

 

[WB9YBM]

A repeater capable of coverage reaching out 8-9 miles may be possible.
$1000 repeater isn't going to get you very far.

"may be possible"? 8-9 miles with a repeater'd be a slam-dunk unless it's running under a watt and using a dummy load for an antenna.

As for a $1,000 price tag for a repeater: yeah, I can almost see it if you had to buy one commercially, bought a few extra options, and did not look for any special deals.

On the other hand someone that's got a bit more technical wherewithal will be able to do more with less money. For example I've put a repeater together with about 15-25 mile coverage (mobile to repeater) with about $15 worth of parts and two spare transceivers that were laying around.

 

[mmckenna]

"may be possible"? 8-9 miles with a repeater'd be a slam-dunk unless it's running under a watt and using a dummy load for an antenna.

I was mainly referring to the 50 foot AGL figure. Might work if the topography is right. Might not work if it isn't.

As for a $1,000 price tag for a repeater: yeah, I can almost see it if you had to buy one commercially, bought a few extra options, and did not look for any special deals.

I think the 50 watt Bridgecom repeaters start around $1200. Can remember if that includes the internal mobile duplexer or not.

On the other hand someone that's got a bit more technical wherewithal will be able to do more with less money. For example I've put a repeater together with about 15-25 mile coverage (mobile to repeater) with about $15 worth of parts and two spare transceivers that were laying around.

I think short of the duplexer, I've got enough stuff to put one together just sitting in the garage. For someone who's never built/tuned one before, it's going to be a bit more difficult.


I heard that the Retrivis unit gets away with the wide channel spread due to duplexers with broad pass bands. Any more than the few watts they put out, and the receiver desenses.

 

[prcguy]

8-9 miles with a repeater antenna 50ft high and the users have hand helds will not work. You will have a few sweet spots outdoors but if you move around it will go down the toilet or go indoors and it just will not work. Been there done that.

If the users have gain type mobile antennas and higher power radios then it will be somewhat useable but still frustrating with lots of weak reception areas. Been there and done that too.

Not counting this idea is doomed due to the low repeater antenna height, you can assemble a very good complete repeater system for under $1k if you know someone with test equipment to help align it. I've picked up many used perfect condition Motorola Quantar repeaters in the $600 range. An adequate 4 cavity BpBr duplexer can run about $250 and sometimes tuned for that price. A used 6dBd or higher gain antenna with 50ft of 1/2" Heliax is about $200 worth of stuff around here.

You cannot build a better repeater than a Quantar no matter what radios you use. The Quantar also has a built in community tone panel if you want to split users up and give them there own tone or DPL. Once a Quantar is tuned up around the GMRS band you can simply plug in a computer and make any changes you want from frequency to tone to CW ID, power levels, you name it. Super easy to program. However, you would not want to waste all that using an antenna only 50ft off the ground in the flat lands. That would be like buying a Maserati and only driving it around parking lots.

"may be possible"? 8-9 miles with a repeater'd be a slam-dunk unless it's running under a watt and using a dummy load for an antenna.

As for a $1,000 price tag for a repeater: yeah, I can almost see it if you had to buy one commercially, bought a few extra options, and did not look for any special deals.

On the other hand someone that's got a bit more technical wherewithal will be able to do more with less money. For example I've put a repeater together with about 15-25 mile coverage (mobile to repeater) with about $15 worth of parts and two spare transceivers that were laying around.

 

[WB9YBM]

you cannot build a better repeater than a Quantar no matter what radios you use. Once a Quantar is tuned up around the GMRS band you can simply plug in a computer and make any changes you want from frequency to tone to CW ID, power levels, you name it. Super easy to program.

The best repeater I've seen is the one I built myself because it does everything I want it to do-guaranteed -but not everyone's in a position to do that. As for computer programming--if you want fancy, fine, but in some cases that's like swatting a fly with a howitzer.

 

[prcguy]

I would be very surprised if your repeater receiver will survive in the worst possible repeater site hell that a Quantar can, with 300 watt UHF paging transmitter antennas snuggled up against your antenna. Will your repeater transmitter loaf along at 110watts out transmitting forever? A Quantar will.

The best repeater I've seen is the one I built myself because it does everything I want it to do-guaranteed -but not everyone's in a position to do that. As for computer programming--if you want fancy, fine, but in some cases that's like swatting a fly with a howitzer.

 

[vagrant]

How does this help the OP? Considering what the OP proposed, how do any of your posts help them to accomplish their goal? Seriously, read the original post and then your own post below and ask yourself if the OP is in a position to do that. In one of your posts you offered an alternative to a duplexer by using a frequency split using 2 meters and 1.25 meters and they're asking about GMRS.

The best repeater I've seen is the one I built myself because it does everything I want it to do-guaranteed -but not everyone's in a position to do that. As for computer programming--if you want fancy, fine, but in some cases that's like swatting a fly with a howitzer.

 

[WB9YBM]

How does this help the OP? Considering what the OP proposed, how do any of your posts help them to accomplish their goal?

Read the posts yourself and you'll see he appreciated my inputs.

 

[WB9YBM]

I would be very surprised if your repeater receiver will survive in the worst possible repeater site hell that a Quantar can, with 300 watt UHF paging transmitter antennas snuggled up against your antenna. Will your repeater transmitter loaf along at 110watts out transmitting forever? A Quantar will.

so will mine. (At least so far.) Might have something to do with the military comms a past employer of mine was involved with (or a lot of common sense & experience).

 

[KevinC]

Can we please get back to hepling the OP and not whose repeater is bigger.

One warning and no need to reply to this.

 

[srbecker58]

I appreciate everyone's feedback, I really do! It has opened my eyes to a world of new information and things to look into and research. It also made me realize that unless I WANT to spend big bucks, that it likely just does not make sense to build my own repeater for the intended use in my OP. If it was for a hunting camp or something, it would be a different story, but for the range I am ultimately looking for, it makes more sense to get a nice base station set up and either use simplex or try using an existing repeater somewhere.

That being said, I will have more posts in the future asking for advice on base station setups and mobile setups, but we can consider this one toast and admins are more than welcome to close it down.

 

[mmckenna]

Investing in better base stations will give you more flexibility.
While building your own repeater, or even buying one used, is an option, there's a lot more to it. Plug-n-play doesn't usually work out well. There's a lot involved in doing it right and making it work well.

 

[srbecker58]

Investing in better base stations will give you more flexibility.
While building your own repeater, or even buying one used, is an option, there's a lot more to it. Plug-n-play doesn't usually work out well. There's a lot involved in doing it right and making it work well.

So I have learned from this thread hahaha!

Now I have to get my base station set up narrowed down. The Wouxun KG-1000G is going to be my mobile unit when it becomes available and the mobile setup is pretty straight forward once I figured out where to mount the antenna.

The base station on the other hand has me all confused as to the best setup as we discussed yesterday. I have some work and thinking to do there still. I am almost deterred in doing a base and just running everything mobile from the truck...

 

[srbecker58]

But then that also means I just wasted $50 on that Ed Fong antenna... but I guess its better than wasting more than that haha.

 

[prcguy]

I've always been a fan of the Bendix King EMV4990A for GMRS. Its wideband only so its only good for GMRS and 70cm amateur, except in So Cal where the idiots went to a 20KHz channel spacing. You can pick up perfect condition versions for about $80 and programming software is free and legal. The radio will also program something like 114 channels, or maybe it was 214 channels, I forget. Anyway I have about 5 of these on my workbench waiting for a local GMRS project to fire up.

These radios were moderately high end when new and high quality US made.

So I have learned from this thread hahaha!

Now I have to get my base station set up narrowed down. The Wouxun KG-1000G is going to be my mobile unit when it becomes available and the mobile setup is pretty straight forward once I figured out where to mount the antenna.

The base station on the other hand has me all confused as to the best setup as we discussed yesterday. I have some work and thinking to do there still. I am almost deterred in doing a base and just running everything mobile from the truck...

 

[alcahuete]

9-10 miles with a 50' repeater and handhelds is not that difficult to achieve, but it certainly depends on the area, buildings, topography, etc.

I don't think it's quite fair to say that the OP's project will not work, period. That just isn't the case. But yes, there are A LOT of factors involved.

If the OP is setting up a base station, that is the perfect chance (without spending a ton of money) to see if a repeater will work. If the handhelds make it in to your base station, you can be fairly guaranteed that they would make it in to a repeater at your house.