Batboard

Hello,

I hope that this doesn't violate the forum rules. I always have learned best by watching and seeing what other people do. Constructive criticism is best to make a better work product. So, I figured maybe to start a thread that has a pic or two of your recent installs. All positive and constructive comments are welcome to have us all make a better install.

Here are one or two of ours below, some of these are during installation and may not be finished completely.


By fmbob at 2012-07-20


By fmbob at 2012-07-20


By fmbob at 2012-07-20


By fmbob at 2012-07-20


By fmbob at 2012-07-20


By fmbob at 2012-07-20

By fmbob at 2012-07-20


By fmbob at 2012-07-21


By fmbob at 2012-07-21


By fmbob at 2012-07-21


By fmbob at 2012-07-21


By fmbob at 2012-07-21

I do have a question about the panels that the CDM mobiles are mounted in. Where were those obtained from?

Jim

Jim,

I make them in house. A simple 3RU Blank rack panel and appropriate Havis Shields brackets. Have a jig set up on the mill machine or try your skill with a jig saw and drill.

However, there is a guy floating around ebay that has them where the opening appears stamped in the rack panel with welded tabs to mount the radios for like $89.00 and it has handles. I am not a fan of the handles, and it does take a bit of time to cut out the openings so buying them pre made may not be a bad idea.

Nicely done Rob. Something to be proud of. You put the craft in craftsmanship.

Only because I'm a grounding freak, it seems a little light on the grounding aspect for the individual racks and components.

Each rack should have a ground bar or 2G vertical ground leg where each component has a 6G going to it. The rack / cabinet would then go to a 2G to the master ground bar, tap into a 2G leg from the MGB with a Ctap or Htap.

I'm sure there are other little things, but overall the project looks clean.

tpg

I've been out of the pro sound business now for about seven years, but as I recall Middle Atlantic made rack panels with cutouts for a variety of Motorola radios, usually two to a panel. Dick Robinson in San Diego also still makes them.

The open rack construction method is great for building the system and service access afterwards, but I always preferred enclosed cabinets with locked rear doors for protection in the event some unauthorized person obtained access to the room.

The antenna connection routing setup looks very good indeed.

Our construction manager is big on grounding too. I think he has the R56 memorized.

I liked those CDM panels too Rob. Nicely done. Do they go to that rooftop antenna farm you showed? I've built a farm or two myself. Some of the time they worked okay, and other times they turned into IM generators and desense makers. I have since started using db Spectra control station bidirectional combiners. Though not very efficient (approx 9db insertion loss), if the dispatch center is well within the footprint of the system they are trying to work, the losses don't matter. They come in all bands in 4, 8, 12, and 16 port models. Instead of an antenna for every radio, you have one tx and one rx ant for each band. Cleans up the roof top nicely, and makes self interference disappear. Not cheap, but when you add up all the savings on hardline, connectors, antennas, and labor, it is almost a wash.

Nice job, very nice job. How's the Tait kit working for you?

But way more grounding needed. The copper feeder ground panels need something like 50mm2 conductors in as straight as possible verticle run to a real station ground (also tied to the tower), even if you have to drill right thru the floors for them The ground runs you have too much inductance to protect against a nearby strike. Also I assume you’re not in a ‘quake zone otherwise the batteries will need tie downs.

I would also have put the roof mounted antennas spread out around the building parapet to give more isolation.

Thanks all for the comments. To answer a few questions, Tait is working out beyond awesome - a far superior product than..... shhh. That pic is one half of an IP based 2 channel voted system with automatic transmitter switch over. The CPU is running all the monitoring software that allows us to completely monitor the system, even remotely log in and program.

As far as the antenna farm, they are indeed for control stations all tied to a one position dispatch console. They can only transmit on one radio at a time and the acutal parapit wall mounts were exisiting, so we reused them. It was a very short run to the back end of the dispatch console, less than 50 feet total. Most of the cables were exisiting, and there was a rusty, crappy frame mount that we cut away and replaced. I have used that DB base combiner once, and it was sweet. I agree with everything you mentioned and it makes sense. We just had alot to work with exisiting there. Those suckers are not cheap.

We are not in a seismic zone, so we didn't strap the batteries down. But those suckers are heavy! If they shake loose, we have some big problems, LOL.

As far as grounding.. Some of the pics were done before completion, so not all grounding was in place. My dilema is that I never really understood the need to a #6 ground from the rack bar to the back of the equipment. I always felt it was way to cumbersome to deal with. Then on the CDM radios, how could you ground them, as there really isn't a good place to lock onto? The few pics with the tait equipment is actually attached to a wood pole installation. The wood pole has hard drawn bare # 2 run down the oppostire side of the wood pole with the ground kits attached to it which runs directly to a ground rod 3' away from the pole. I am hoping that will do the trick on that. On the inside the electrician ran the #2 back to the building cold water/electric gorund, which the lightning arrestors, inside gorund kits, and RGB is tired to.

The enclosed cabinet and combiner pic is an in building system with internal antenna network, with no outside antenna. I did go light on the ground in the rack, and the pic with the top of the combiner and ground bar was before the electrician ran the master gorund feed to it. I ran #6 over to the RGB from the ground bar. Any thoughts on the grounding is always welcome, it has always been sort of a learning curve.

I'm guilty of the same thinking about grounding. If the rack is grounded, and the equipment is bolted to the rack, why is an additional ground lead required? I always lose the argument. The standards are the standards. I still haven't mastered the compression crimps required for attaching to the halo, but I'm getting better.

Bill, See that is funny. I haven't seen a halo ground go into a site or shelter in a long time. Not even the high end cell installations are doing it much at all any more. I used to see that on the Netel site spec alot. Maybe it is the fact that a majority of the installs are pad mounted outdoor cabinets, but still all I see for that is a #2 through bolted into the cabinet to the site gorund. On the inside of the cabinet is tied into a small ground bar and fromt he ground bar to the back of the radio units etc.

The cellular guys seem to be able to do whatever they want. Sometimes they don't even cad-weld their ice bridge to the halo. Wait until you have to build to Union Pacific standards. The 7/8ths has to come straight down the tower to a right angle adapter with a ground lug. The 7/8ths into the building has to come off the 90 deg straight out. The 180 lug attaches to a #2 bare coated copper straight down and cad-welded to a buried ground halo. No bends or curves allowed. Has to be straight. If you have more than one antenna, they each get their own ground lead. Very industrial art looking when completed. Thing of beauty. And yet, they don't require an additional ground at the cable entry window. Their line goes to a polyphaser mounted on a ground bar inside.

Power companies want their racks isolated from the concrete floor with thick red fiberglass insulator pads with nylon washers on the bolts. The racks cannot touch each other. Three inch minimum distance between racks. A strand of #2 from each rack to a 1/0 halo or home run to a ground bar.

Bill_G wrote: I have since started using db Spectra control station bidirectional combiners. Though not very efficient (approx 9db insertion loss), if the dispatch center is well within the footprint of the system they are trying to work, the losses don't matter. They come in all bands in 4, 8, 12, and 16 port models. Instead of an antenna for every radio, you have one tx and one rx ant for each band. Cleans up the roof top nicely, and makes self interference disappear. Not cheap, but when you add up all the savings on hardline, connectors, antennas, and labor, it is almost a wash.

I have been looking for such a device for a very long time. Thank you for posting this!

resqguy911 wrote:

Bill_G wrote: I have since started using db Spectra control station bidirectional combiners. Though not very efficient (approx 9db insertion loss), if the dispatch center is well within the footprint of the system they are trying to work, the losses don't matter. They come in all bands in 4, 8, 12, and 16 port models. Instead of an antenna for every radio, you have one tx and one rx ant for each band. Cleans up the roof top nicely, and makes self interference disappear. Not cheap, but when you add up all the savings on hardline, connectors, antennas, and labor, it is almost a wash.

I have been looking for such a device for a very long time. Thank you for posting this!

We have also used them in 800MHz for trunking stations, full 16 port unit running 12 or 13 radios. Works great as long as your system footprint is strong where your base radios are at, as you said. It was nice to only have to mount a couple of antennas, rather than 13! We even put up a spare, lol.

Looks good. How do you like the 9100's? We just became a tait dealer, the second in mass. I think tait is lightyears ahead of many base stations out there, especially the task manager. Are you using microwave or fiber to backhaul? What are you running for server logger?"I am just learning their equipment and so far i am impressed.

Another Tait dealer in mass, you have some stiff competition out of norwell. I can't say enough great things about the tait equipment. I don't know why anyone would use anything else in the way of base equipment?

We have been using microwave as our backhaul. As far as server logger there are many programs such as kiwi and intermapper.

The Pager Geek wrote:Each rack should have a ground bar or 2G vertical ground leg where each component has a 6G going to it. The rack / cabinet would then go to a 2G to the master ground bar, tap into a 2G leg from the MGB with a Ctap or Htap.

Heh, you sound like the guy at the pipeline company site I was at a few weeks ago. A bear for his C-taps and minimal bends in the wire he was. He also informed my partner and I that a crimper for the C-taps runs something like several thousand dollars? That's partly why I haven't invested in my own personal set of Cadweld tools.. those clamps and molds get expensive real quick.

OP: looks top-notch. I especially like the waveguide port in the ceiling where the hardline comes in, instead of just a hole in the drywall.. little things like that will help you earn a reputation for quality work. The wiring on your Newmar power supplies could stand a little tidying-up, but that's a minor nitpick.

Like I said... I'm a grounding freak. (8" minimum bend radius btw)

You could use split bolts, but I've seen so many come loose over time where they just spin off by touching the side of them.

The hydraulic I use is Burndy BAT 750, 12 ton "handheld" crimper. It was around $3k, but worth it compared to my back-up hand crimper (Burndy Y750) at $2k. After doing 2-3 lugs with the hand operated, you'll never complain to the electric one. Oh, don't forget the die set! Another $1k.

I use it regularly with 2-3 site installations per month. Finished off one today... so it's the cost of business for me.

tpg

FMROB, how does well does the battery revert work on the mtr3000 using the samlex charger and samlex lvd, is the base station fine with ac and dc supplied at the same time without isolation as the Argus unit does? thanks

The original post is about a year old.

In looking at the photos, one item popped out at me. The rack that showed the tower top preamp is being powered by an extension cord with black cable and a yellow socket. Not really sure about the electrical inspector where those pictures were taken, but around here, you would need emt with a junction box mounted to the cable tray. The outlet would be either a single duplex or double duplex outlet in the junction box.

Other than that, a well done install.

Jim

Refreshing the post: This is 2 TK-880's, plus the CPI panel for mounting TTP's.:

http://batboard.batlabs.com/viewtopic.p ... 69#p461157

Which turned into this:



and



The 26 (about) radios used to occupy 2 whole racks, mounted on simple shelves. Not cool, looked like *ss:



(Apologies for the blur & such.)
I'll dig out the ones I've done with CDM1250's, similarly

Very nice install on the mobiles, looks great. Jim, the pre amp is in fact being powered by SJ cord over to the rack mounted UPS. It was a temp measure until the union electricians ran dedicated circuits into the room from their rather room size UPS units, but that was some weeks away. If that preamp loses power or blows it really can ruin the day, so we wanted to get it on some temp ups coverage. They have also have large generators, but they take a bit to power up the building.

Rob

Like seeing CPI equipment installed in the field!

Holy intermod batman! How do you deal with the antenna systems on one of these installs.