Building a new repeater for Columbia SC

[Guest]

This is something I've wanted to do for a while - but haven't had the drive to do so.

 

I am building a medium-duty repeater out of 2 Motorola CDM1250 mobiles, Astron power supply, duplexer, and a decently-advanced i750r Repeater Controller that allows for multiple PL/DPL access codes, along with MDC1200 access and setup/knockdown. I was liking the MDC idea since if I cannot find a location to make this repeater public, I can keep it quiet and "locked down".

 

Now - for the biggest hurdle. I COULD put it up in my attic, run cooling fans on the TX radio, and stick a j-pole on my roof - but that's not going to be so effective and not good for the community (which the closest repeater that's working now is 20mi LOS to my west). I want to find a place to house the repeater - but have not a single clue where to begin! How has most people here managed to find a tower for their repeater?

 

 

[zap]

I've usually asked the local Emergency Management Coordinator (usually works for the county) to see if they know of any good (yet zero to no cost) places to start that kind of thing.

 

On the repeater technical side, I've never dealt directly with the CDM series but I do know the receiver on the CM/PM series can get a little warm. Many more modern Motorola radios have pre-drilled holes pilot holes that could be used for a fan on the heatsink.. The GR300/500 repeaters used the Zentron controllers. I have one with an i50r (autopatch) controller but it can also be setup for MDC knockdown (not DOS). On the GR300's, the transmit GM300 has a thermresistor on it which activates a fan (GM300's also back down power based on an internal temperature control). Just some thoughts/ideas for you.

[Guest]

Thanks for the ideas. A little bit of searching and I found an adapter that was made for the CDM series to allow a 60-80mm fan to be bolted to the heat sink. I would probably just do that and let them run wide open all the time. As for the repeater panel - I have the RSS for it but no manuals, and the RSS is the old 486-speed DOS kind. So I won't be playing with that until I get an old computer around to load it up on. DOSbox didn't play well with it. If I end up making a community repeater though I'd save the controller for a repeater I want to put up at my in-laws house. They have zero cell coverage in the entire town so it's nice to talk back and forth there.

 

I am going to see what the OEM Coordinator might have to say about tower space though. I know from one other repeater owner here that it worked for him. They matched him up with a TV station tower that was giving away space to the county.

 

 

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[zap]

Check repeater builder for GR300/500 controller programming manuals. If your controller is covered in there, a dual core machine with hardware serial port booted in FreeDOS will work just fine. Some programs Zentron also wrote windows versions of.

 

 

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[Logan5]

Check repeater builder for GR300/500 controller programming manuals. If your controller is covered in there, a dual core machine with hardware serial port booted in FreeDOS will work just fine. Some programs Zentron also wrote windows versions of.

 

 

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is there a linux or rasberry pi version of this?

[zap]

No. I mean, FreeDOS is opensource DOS…but doesn't currently support Arm architecture

 

 

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[Guest]

Sadly the GR300/500 explicitly skip the controller and call for another set of manuals for its service and programming.

 

I was lucky enough that someone on another site had the same controller and managed to find the RSS, but no manuals still - and from what he told me the RSS is VERY convoluted. If I am to build a repeater, I might pick something else to use as the controller and save the i750r till I have all documentation and the opportunity to pull the PCB out of the case and clean it down real well. The 3 16-pin connectors on the back have some weather corrosion so I can only assume the PCB needs to be cleaned up as well.

 

I am also picking up a GR300 chassis to put the CDMs into - I know I might need to snip/dremel a bit to make it work, but I think it would be a clean setup to house radios, controller, duplexer, and power supply in one box.

 

Lastly picking up an old Panasonic Toughbook to turn into my "programming laptop". Still debating if I need to get an old PII system like a CF-27 for DOS and use my new thinkpad for the newer stuff, or get something like a CF29/CF30 and try running XP and DOS dual boot.

[zap]

I dual boot my CF-28 (P3) for XP and DOS. It actually houses all of my Depot software on the XP side...

 

Anyway, the controllers that were stock options (and covered in the Motorola Manuals) will actually program in the GM300 RSS. Now, Zentron had an RSS for non Motorola customers as well (which didn't require the Motorola licensing). Like I said, that manual is available on RBTIP (under the Maxtrac/GM300 page).

[Guest]

I dual boot my CF-28 (P3) for XP and DOS. It actually houses all of my Depot software on the XP side...

 

Anyway, the controllers that were stock options (and covered in the Motorola Manuals) will actually program in the GM300 RSS. Now, Zentron had an RSS for non Motorola customers as well (which didn't require the Motorola licensing). Like I said, that manual is available on RBTIP (under the Maxtrac/GM300 page).

 

I am thinking of picking up a Toughbook to keep as a programming/field computer and load it with other random items as well for taking it places. There's a few CF-28s out there but I am wondering if a CF-29 would be able to take place and still boot under DOS via USB... would that work?

[zap]

Yes. A 29 May even boot windows 7 if you're wanting an OS still under support (recommended for any internet usage).

 

The bios I'm the 28 doesn't support booting via USB.

 

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[Guest]

That's good news for me. I've been looking at a CF-18 or early CF-19, and the CF-29 or early CF-30 as well. Still debating whether I want small or big. Also on that list is the Motorola ML910 and a Getac V100 I've been watching on eBay. All of them are either Core Duo or Core 2 but the earliest versions of them.

 

 

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