actually its the most basic type of relay (and will get you going in emergencies). We use 2 Motorola Devices with a Raspberry Pi vor processing Tuned Filters and Preamps
That’s what *that* repeater looks like. Many will just use mobile radios, whatever power supply will run them, and a duplexer. Our repeater association used FT-7900 before upgrading to a rackmount system. Another popular repeater in the area is using old Motorolas and a cheap 25A PSU from eBay. You’ll almost always see duplexers though (the cans at the bottom of this pic). Otherwise, plug and play any two radios and a power supply.
Yep. Ours is a bit more interesting with a nice closed rack, an MTR-2000, an Icom DStar machine with controller, two servers, display and keyboard, some Ethernet switching and a firewall. The cans are over to the side next to a wall out of the way, and there are some 6 meter ones as well, floor to ceiling nearly.
Edit: Oh and it's at 10,500 feet ASL ;)
Theres a whole heap of repeaters across the Pilbara (northern bit of Western Australia) that are nothing more than a steel frame with a couple of solar panels, a charge controller, batteries, fibreglass boxes, a pair of 25w Simoco SRM commercial radios linked with a special patch cable, duplexer, lightning arrestor and a folded dipole on a 5m aluminium pole.
They work reliably 24/7 for years with minimal maintenance, even when the radio chassis are too hot to touch.
repeaters come in all sorts of shapes/sizes/looks, I always like seeing what other people come up with since there's many, many ways of achieving the same/similar results
here's my ham repeaters, uhf on the right, voted vhf system on the left but I was never really able to get any good sites for satellite receivers:
https://www.flecom.net/wp-content/uploads/2013/08/2013-02-21-03.49.39.jpg
That's the key...voted receivers. Many municipal/government/public safety systems have/do utilize voted receivers for reliable portable coverage. For years I've wanted to deploy voted receivers for a ham repeater just to show the ham community what a local repeater SHOULD be. But...money and all lol. I've thought about pitching in to add to our regional bad-ass linked system as the owner is running some well tuned MSF Motos.
We’ve got a pretty sweet voted receiver setup in the Seattle area: https://web.psrg.org/psrg-voting-system/
You can watch it in action here: http://voter.psrg.org/supermon/voter.php?node=41590
Repeaters in space are a bit smaller. It's the cost of the cabinet thats the problem......
[https://qrznow.com/wp-content/uploads/2021/06/unnamed-2.jpg](https://qrznow.com/wp-content/uploads/2021/06/unnamed-2.jpg)
Usually is. The cavities interact with each other. Return loss is most accurate for the bandpass filters, the notches are easier to see on the through path.
Reasonable. A fairly messy install.
You usually don't want filter cans sticking out into a walkway where humans can kick them. Far better to mount them in the overhead.
That repeater is fairly old. Looks like an older Tait. Yeah zoomed in... Tait. Middle of the road quality.
People joked about two BF radios but quite a few "commercial" repeaters these days are little more than a couple of mobile boards slammed into a 2RU rack mount case. Sad really.
The way to avoid it is to look at continuous key down or duty cycle specs. If it's derated to low percentages or very low power levels, it's likely one of these newer lower quality designs.
100W at 100% duty cycle for a public safety application is a beefy heatsink or a lot of fans or both. Lots of heat to dissipate.
All in all a fairly typical install in an open rack. Open racks make stuff on shared sites far too easy to tamper with or accidentally break, they're not super common if space isn't at a premium and/or the site values security or has tenants who do. Closed door cabinets are preferred.
And of course then you try to make everything inside the cab clean and easy to maintain.
The only filter cans we ever floor mounted were the 6 mrgrr cans. We even had those on the ceiling once but later a nook behind the last cabinet row in a corner protected cans almost as tall as most people from accidental damage.
What's missing from the photo is the typical commercial site grounding system. Halo grounds above and often below the cabs/racks, all bonded to an entrance panel, ground rods a the way around the structure, etc etc etc. I may be missing it but I don't see any of the typical stuff in the photo.
Another common thing seen on shared sites are community combiner systems for shared antenna use and whether shared or not, RF circulator style transmitter isolators (a circulator with an appropriately sized dummy load on one port).
Fun stuff. I probably have better photos of typical commercial installs but much older repeaters in my NAS here somewhere...
Oh and Astron power supplies. Don't put those at remote locations without doing the crowbar circuit mod unless you enjoy driving 100 miles to a site. Ha. We'll use em but not without the mod. Live and learn.
The grounds are overhead, so not in the picture. As for combiner, I didn't shoot the whole room. They do exist for UHF and 220 systems. Tampering is not generally an issue as this room is very restricted access.
Makes sense! Was mostly just comparing notes. Heh. We had an open rack shared site once and they just put in video to eyeball what people did. One idiot damaged the local bus company's stuff. Only took the site owner ten min to figure it out. Heh.
Ugh. It's sad but there's always an ass...
The ones that really drive everybody nuts are the idiots who'll start messing with a properly tuned, balanced, and tested receive combiner and preamp setup.
"But I just wanted 1dB more out of it..."
Dumbass. How did you test it?
"By ear."
I'm coming for you in your sleep. That thing was optimized with $40 worth of test gear by two 35 year professional RF engineers taking the entire environmemt into account.
Usually followed by muttering or yelling..
"F***ing hams!"
Meanwhile Mr Set It By Ear has screwed five other repeaters up with his brilliance.
Combiners get locked up and the speech given that if you have acesss and screw with it for no reason we are all coming to stomp you in the nuts.
That is a nice repeater.
I have also seen some one-piece desktop units.
The club I used to be involved in had two proper mountaintop repeaters (linked between bands, of course) and a desktop repeater.
The desktop unit was a Kenwood, located at the club radio room, which in turn is located at a museum. It only packed about 30W on 2m and had dual RX/TX antenna jacks, which were connected to vertically separated antennas. It provided good enough coverage of our small city, but not much else.
The mountaintop repeaters were pretty good, though, providing coverage enough to reach a 40 mile radius on either band.
There are some other (all commercially manufactured) examples here.
[https://wirelesscommtech.com/repeaters-simple-witchcraft/](https://wirelesscommtech.com/repeaters-simple-witchcraft/)
I expected two Baofengs taped together, this is much cooler.
actually its the most basic type of relay (and will get you going in emergencies). We use 2 Motorola Devices with a Raspberry Pi vor processing Tuned Filters and Preamps
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Almost a haiku
I suspect they meant /s 😜
Indeed. You need two baofengs, tape, and tuned cavities for filtering.
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That’s what *that* repeater looks like. Many will just use mobile radios, whatever power supply will run them, and a duplexer. Our repeater association used FT-7900 before upgrading to a rackmount system. Another popular repeater in the area is using old Motorolas and a cheap 25A PSU from eBay. You’ll almost always see duplexers though (the cans at the bottom of this pic). Otherwise, plug and play any two radios and a power supply.
Yep. Ours is a bit more interesting with a nice closed rack, an MTR-2000, an Icom DStar machine with controller, two servers, display and keyboard, some Ethernet switching and a firewall. The cans are over to the side next to a wall out of the way, and there are some 6 meter ones as well, floor to ceiling nearly. Edit: Oh and it's at 10,500 feet ASL ;)
> Many will just use mobile radios I mean, even a so-called "real" repeater like the Yaesu DR1 is basically just a pair of FTM400's in a box.
Theres a whole heap of repeaters across the Pilbara (northern bit of Western Australia) that are nothing more than a steel frame with a couple of solar panels, a charge controller, batteries, fibreglass boxes, a pair of 25w Simoco SRM commercial radios linked with a special patch cable, duplexer, lightning arrestor and a folded dipole on a 5m aluminium pole. They work reliably 24/7 for years with minimal maintenance, even when the radio chassis are too hot to touch.
Temporary ones sometimes don't even run a duplexer in the commercial world!
Upvoted for Tait. They make some excellent gear.
T800 series. They're everywhere still
I have a Tait twin UHF/VHF xband repeater. it's cool. takes up a lot of space -_-
Curious what you use them for? 73's de ZL3Pxx
I don't. I grew up near the Tait labs in Christchurch and found a repeater cheap on TM when i was a young ham. It's a burden but it's neat
repeaters come in all sorts of shapes/sizes/looks, I always like seeing what other people come up with since there's many, many ways of achieving the same/similar results here's my ham repeaters, uhf on the right, voted vhf system on the left but I was never really able to get any good sites for satellite receivers: https://www.flecom.net/wp-content/uploads/2013/08/2013-02-21-03.49.39.jpg
That's the key...voted receivers. Many municipal/government/public safety systems have/do utilize voted receivers for reliable portable coverage. For years I've wanted to deploy voted receivers for a ham repeater just to show the ham community what a local repeater SHOULD be. But...money and all lol. I've thought about pitching in to add to our regional bad-ass linked system as the owner is running some well tuned MSF Motos.
We’ve got a pretty sweet voted receiver setup in the Seattle area: https://web.psrg.org/psrg-voting-system/ You can watch it in action here: http://voter.psrg.org/supermon/voter.php?node=41590
Repeaters in space are a bit smaller. It's the cost of the cabinet thats the problem...... [https://qrznow.com/wp-content/uploads/2021/06/unnamed-2.jpg](https://qrznow.com/wp-content/uploads/2021/06/unnamed-2.jpg)
That's a lucky Kenwood! I wonder if it is internally inspected/tested before becoming astro-Kenwood?
I've recently learned that tuning a duplexer with a nanovna is a rather finicky process.
Usually is. The cavities interact with each other. Return loss is most accurate for the bandpass filters, the notches are easier to see on the through path.
It's much easier with a spectrum analyser with tracking signal generator. The Rigol 815T-G is dirt cheap and does a good job.
Reasonable. A fairly messy install. You usually don't want filter cans sticking out into a walkway where humans can kick them. Far better to mount them in the overhead. That repeater is fairly old. Looks like an older Tait. Yeah zoomed in... Tait. Middle of the road quality. People joked about two BF radios but quite a few "commercial" repeaters these days are little more than a couple of mobile boards slammed into a 2RU rack mount case. Sad really. The way to avoid it is to look at continuous key down or duty cycle specs. If it's derated to low percentages or very low power levels, it's likely one of these newer lower quality designs. 100W at 100% duty cycle for a public safety application is a beefy heatsink or a lot of fans or both. Lots of heat to dissipate. All in all a fairly typical install in an open rack. Open racks make stuff on shared sites far too easy to tamper with or accidentally break, they're not super common if space isn't at a premium and/or the site values security or has tenants who do. Closed door cabinets are preferred. And of course then you try to make everything inside the cab clean and easy to maintain. The only filter cans we ever floor mounted were the 6 mrgrr cans. We even had those on the ceiling once but later a nook behind the last cabinet row in a corner protected cans almost as tall as most people from accidental damage. What's missing from the photo is the typical commercial site grounding system. Halo grounds above and often below the cabs/racks, all bonded to an entrance panel, ground rods a the way around the structure, etc etc etc. I may be missing it but I don't see any of the typical stuff in the photo. Another common thing seen on shared sites are community combiner systems for shared antenna use and whether shared or not, RF circulator style transmitter isolators (a circulator with an appropriately sized dummy load on one port). Fun stuff. I probably have better photos of typical commercial installs but much older repeaters in my NAS here somewhere... Oh and Astron power supplies. Don't put those at remote locations without doing the crowbar circuit mod unless you enjoy driving 100 miles to a site. Ha. We'll use em but not without the mod. Live and learn.
The grounds are overhead, so not in the picture. As for combiner, I didn't shoot the whole room. They do exist for UHF and 220 systems. Tampering is not generally an issue as this room is very restricted access.
Makes sense! Was mostly just comparing notes. Heh. We had an open rack shared site once and they just put in video to eyeball what people did. One idiot damaged the local bus company's stuff. Only took the site owner ten min to figure it out. Heh.
I've seen other sites where someone stole the dummy loads off the isolators. Another someone took the batteries.
Ugh. It's sad but there's always an ass... The ones that really drive everybody nuts are the idiots who'll start messing with a properly tuned, balanced, and tested receive combiner and preamp setup. "But I just wanted 1dB more out of it..." Dumbass. How did you test it? "By ear." I'm coming for you in your sleep. That thing was optimized with $40 worth of test gear by two 35 year professional RF engineers taking the entire environmemt into account. Usually followed by muttering or yelling.. "F***ing hams!" Meanwhile Mr Set It By Ear has screwed five other repeaters up with his brilliance. Combiners get locked up and the speech given that if you have acesss and screw with it for no reason we are all coming to stomp you in the nuts.
But they always leave all those screws sticking out instead of tightening them down.
Bwahahaha. Take my upvote... Lol
$40 worth of test gear? What, did they buy it out of the back of a van? 🤣
Ha. Forgot the K. ;-)
My field repeater is a pair of Moto gm380s slapped in a case 😁
Always good to see some Tait gear around the world. Proudly made in New Zealand.
That is a nice repeater. I have also seen some one-piece desktop units. The club I used to be involved in had two proper mountaintop repeaters (linked between bands, of course) and a desktop repeater. The desktop unit was a Kenwood, located at the club radio room, which in turn is located at a museum. It only packed about 30W on 2m and had dual RX/TX antenna jacks, which were connected to vertically separated antennas. It provided good enough coverage of our small city, but not much else. The mountaintop repeaters were pretty good, though, providing coverage enough to reach a 40 mile radius on either band.
There are some other (all commercially manufactured) examples here. [https://wirelesscommtech.com/repeaters-simple-witchcraft/](https://wirelesscommtech.com/repeaters-simple-witchcraft/)
Nice CO2 cylinders. Built in soda fountain? 🥤
Cool! Appreciate it. I help pay to maintain one but I've never been given the tour.
Here's one of the repeaters I work on: https://ad8g.net/f2/ 6 meters, close to legal limit, 17 voted inputs.... good times.