AnonDOG
@kaballero.com
| Need some advice from you EE types.
We have no option but to install and make work six Tranzeo backhauls and 3 Canopy 900 MHz AP on an FM radio tower operating with 6.5 KW from about 300'.
We are installing at 260' and are running POE to the radios from the ground.
Have to have this done in 4 hours on Monday evening. We get 4 more hours on Tuesday evening to fix it if it is still broke.
My concerns are the issues with induced currents in the Cat-5. Want you electrical engineers with experience in this arena to tell me what you would do.
Not installing is NOT an option so we don't need to discuss that.
Thanks in advance.
-m- |
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kewlkeed
Grouch
Premium
join:2005-02-05
Knowlton, QC
| Good lord, you've got a good one. I don't want to drag my Tranzeo grudges into this one, but they might be probably the most in-tolerant units to induced crap on the line.
That said, it's been done many times before. Just make sure the grounding is perfect, shielded cables all the way, filters on the radios if you can...
I'm sure you'll be able to do it, if there's someone out there who can, it'll be you 
--
Justin - DSLR resident grouch and Mr Negativity
TSI Fanboy - "Dontchya wish your 'net was hot like mine! Ohhh Dontchya!"
Have a nice day! |
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petecarlson
join:2004-11-06
Baltimore, MD
| reply to AnonDOG
»www.superioressex.com/communicat···x?id=324
...
I would run a 2" thick wall conduit all the way up and then run BBDGE cable inside of that. Ground the cable at the bottom and float the top. No idea how you plan on doing that in four hours.
If you want to try running it without the conduit, add a ground clamp every 50' or so just like you would with LMR. Off of the top of my head, the 1/4" sureflex ground clamps should work with this cable.
We stay off of towers for the most part so I am not sure how one would secure the cable without conduit. How do tower guys deal with cat5 wire management? |
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bac522
join:2003-08-04
Manchester, NH | reply to kewlkeed
I'd be more concern with powering the radios via POE at 260' first. |
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AMD Phreak
Premium
join:2003-12-14
| reply to petecarlson
I have no comments on the dealings with of high power fm but I do on the cable management.
You can run the wire up the tower in the cable management ladder if permitted. Get some snap ins and use waveguide cushions for cable support. Likewise you can use the waveguide cushions and clamps to attach to a round tower leg or tubular type tower.
Worse case you have to just directly ziptie with heavy duty zip ties, the cable right to the tower. If you let me know the tower type and any existing cable support structures you may have access to I can whip you up a parts list.
I would also have a decent sized crew since you have a limited amount of time.... perhaps 6 guys... four top hands two ground hands and a crew boss.
--
"No job is so important, and no service is so urgent that we cannot take the time to perform our work safely."
-- AT&T, Your World, Destroyed.
--Safety One Tower Rescue Certified
--LLigetfa:"Wimax is like teenage sex. Everyone talks about doing it." |
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AnonDOG
@kaballero.com
| reply to AnonDOG
Everyone thank you and please keep the ideas coming.
I want to run this past you guys though.
We have decided to individually ground each CAT-5 shield at top and bottom. Then individually wrap each CAT-5 in aluminum sticky tape (used for air conditioning systems) from the end of the run to the bundle and then wrap the entire bundle in that same aluminum tape. Top to bottom as it were. Then we will run the bundle inside the tower strapped to a leg and grounded every few feet directly to the tower leg with a wrap of that same Aluminum tape.
Does that make any sense to you guys?
If you would change it, how would you change it.
Again thanks so much.
-m- |
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AMD Phreak
Premium
join:2003-12-14 | Meh.....
I think running bbdge with appropriate heliax ground kits would suffice. I'd put kits top, mid, bottom, and shelter entrance.
Wrapping in foil tape in my mind screams intermod problems. |
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AnonDOG
@kaballero.com
| said by AMD Phreak  :Meh..... I think running bbdge with appropriate heliax ground kits would suffice. I'd put kits top, mid, bottom, and shelter entrance. Wrapping in foil tape in my mind screams intermod problems. Bud,
I am a computer scientist, not an EE but I have an EE reading the thread so you just keep it coming.
We absolutely HAVE to make this work Monday evening. Our network is centered on three water towers we have been required to rip the guts out of the network by July 1.
This one means we save our network. So just keep it coming folks.
Thanks
Mike |
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AMD Phreak
Premium
join:2003-12-14 |
Have the ee look it up on the web.... a lotof info can be had on the subject from ham radio sites.
Did you need a workup of parts for cable support? |
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AnonDOG
@kaballero.com
| said by AMD Phreak ::) Have the ee look it up on the web.... a lotof info can be had on the subject from ham radio sites. Did you need a workup of parts for cable support? I did not find much on the web. I think we will be ok on parts lists but if you have links, we could use those.
Thanks
Mike |
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AMD Phreak
Premium
join:2003-12-14 | I will get you some links in a few.... |
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gunther_01
Premium
join:2004-03-29
Saybrook, IL
| reply to AnonDOG
I'm along the lines as Pete with his cable But I would skip the conduit. Float the ground on the Ethernet shield (Do tranzeo's have shielded ethernet?) so you don't have loops.
But I'm no EE and I didn't sleep at a Holiday Inn Express either  |
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AMD Phreak
Premium
join:2003-12-14
| reply to AnonDOG
»www.tek.com/Measurement/App_Note···ence.pdf
»en.wikipedia.org/wiki/Intermodulation
»www.rfcafe.com/references/electrical/pim.htm
»www.ieee.li/pdf/essay/passive_imd.pdf
Scraps of metal and things of the sort simply laying around the site can even cause intermod issues.
I'm sure there are more references, so search around.
--
"No job is so important, and no service is so urgent that we cannot take the time to perform our work safely."
-- AT&T, Your World, Destroyed.
--Safety One Tower Rescue Certified
--LLigetfa:"Wimax is like teenage sex. Everyone talks about doing it." |
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AMD Phreak
Premium
join:2003-12-14
2 edits | reply to AnonDOG
Waveguide Cushions
»www.tessco.com/products/displayH···ntPage=1
Angle Adapters
»www.tessco.com/products/displayP···ntPage=1
Standoff kits and round member adapters
»www.tessco.com/products/headerPr···hField=1
1/4" or 3/8" ground kit
»www.tessco.com/products/displayP···ntPage=1
Penetrox A13
»www.tessco.com/products/displayP···ntPage=1
Harger CU Joint Compound
»www.tessco.com/products/displayP···ntPage=1
Cold Galv spray paint
»www.tessco.com/products/displayP···ntPage=1
If you are bonding the ground kit to the tower, depending on the ground system existing, you should bond to the buss bar. If not, bond to the tower using angle adapters if flat angle iron style tower, or standoff and round member adapters.
CU to CU joints should be coated lightly in CU joint compound for corrosion resistance. Coat the stainless steel joint threads with a touch of Penetrox for antiseize. I use a very light coat of Penetrox between the stainless hardware and the tower itself to ensure clean oxidation free contact. If you scrape paint or damage the galvanization any, several light coats of cold galv spray should fix it.
I also use CU joint compound between buss bar and ground lug. All bolts, nuts, and washers used should be stainless steel.
--
"No job is so important, and no service is so urgent that we cannot take the time to perform our work safely."
-- AT&T, Your World, Destroyed.
--Safety One Tower Rescue Certified
--LLigetfa:"Wimax is like teenage sex. Everyone talks about doing it." |
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Inssomniak
Premium
join:2005-04-06
Cayuga, ON | reply to AnonDOG
4 hours.?
Wow.
hope you got a crew.!
I plan 4 hours to install just 1/2 a backhaul., but thats only 2 of us. |
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prairiesky
join:2008-12-08
Springstein, MB
| reply to AnonDOG
get as much done on the ground as you can. Crimp the RJ 45s, put them into the radios. That way, someone climbs, pulls the radios connects them and starts cable tieing on the way down while you get the rest of your stuff done on the ground.
b |
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nunya
SEE ROCK CITY 475 MILES
Premium,MVM
join:2000-12-23
O Fallon, MO
clubs:
 ·AT&T CallVantage
| reply to AnonDOG
Lose the aluminum tape idea. This probably isn't the time or place for homespun trials.
LFMC on the verticals to the tower, heavywall RMC up (or well supported LFMC). Run power up inside the the conduit with MC cable. Pull your Cats in last. Lube it up good on the ground and use a sheave to draw the muletape up the pipe from a ground man. (nobody on the tower should be pulling cable)
--
Looks like Reverend Wright got his wish - God Damn America. |
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warwick
join:2009-06-05
Hollywood, FL
2 edits | reply to AnonDOG
Hmm, you've certainly got your hands full. But provided you have the equipment, can be done in less.
Although no EE, (economist) - here is what I would do:
As for the rather extensive lenghth of cat5e required to do a power run, I'd negate the cat 5 all together and instead go with a "glass" solution whilst sending the power up via its own dedicated line.
...Get the required length of shielded optical data line (weather resistant to be more circa), if space permits you can place a switch at the top with a built in media converter that would span out into however much radios you need. (This would be perfect for scalability!!) and voila! ...
As for the power, im not sure if the named radios use 48v or 12v but im assuming somewhere within the range... you can merely use voltage converters for this task (personally I would not send no less than 77v dc up there) This too having its own line. I suppose someone else can aid in stating the appropriate gauge.
Truly, with that much power being radiated; the entire tower is essentially serving as an element and by using straight Ethernet runs "up the way" your more than likely BOUND to incur problems pushing anything over 10 megs half duplex - for this reason I shall stress the fiber word again
Heh, you'd be only pulling TWO cables up there as opposed to what you would otherwise.
Im pretty certain you'd be able to find a decent but reasonable sized enclosure that will fit all of the aforesaid.
Here is a MUST read, if you havent already --- talks EXACTLY about what you'd face by opting for standard ethernet, whether it be outdoor rated or otherwise.
»www.isp-planet.com/fixed_wireles···+fm.html
Just my $0.02! |
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Believer
join:2002-07-04
Baltimore, MD
| Different towers have different rules on cable attachments. However, running and attaching lines to 260' could take 4 hours by itself. Ditch the conduit idea completely.
Zip tie the cables to the cable management ladder or someplace within easy reach of where you climb the tower. Cut the ends off and wrap them in outdoor electrical tape. CUT the end of the tape off, don't pull it as it will cause it to unravel over time.
Only run two wires up the tower if you can. One 24V power and one Cat5. Anyone know how many Tranzeos you can daisy chain off a direct 24V power supply? Connect your Canopy's to a CMM and plug your Tranzeo ethernet into it and connect the Tranzeo PoE to the CMM's power supply in the same box.
If you can daisy chain all six in a row, that will reduce the number of lines you are running back to the CMM.
With four people climbing, I think you could knock this out in four hours depending on the size of your mounts. If you plan on mounting three, 120 degree 900 MHz sectors with 2ft standoffs, you'll need a really experienced crew to get this done in four hours.
--
Comtrain Certified Tower Climber |
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superdog
I Need A Drink
Premium,MVM
join:2001-07-13
Lebanon, PA
| I am going to second the fiber run up the tower. You can build the boxes and everything inside so that all you have to do is plug and play. This will cut down on the tower time immensely. If everything is ready, you can climb up, bolt the stuff fast, plug it in, test it and get off.
Have EVERYTHING ready, I.E. all of the bolts for the mounts taped fast to the back of the radios, taped to the back of the sectors, 3 foot jumpers attached to the sectors and weatherproofed at that end etc. ANY process that can be done ahead of time?, DO IT!.
Make any Ethernet jumpers ahead of time too. Attach them to the back of the radios, plug them in, test them and put those jack ass Tranzeo covers on and the connectors and tape it all together so all the tower tech has to do is cut or unravel the tape.
You need to number every radio and write the IP address on the back in big letters and numbers (When you are finished, and everything is working, it takes hem 2 seconds to cover it up with magic marker for security reasons). Any part, bracket, jumper etc. needs to be labeled with the associated number that corresponds to the radio it is being used for. This avoids confusion for anyone who touches the radio in question that didn't originally configure it on the bench. This also helps the tower techs when they are asked which radio it is they are working on. Instead of yelling up the tower or getting on the 2 ways 1000 times, all they have to do is look at the radio and give you an answer.
Michael, I know you already know this one too, but I will say it again, just to make myself feel better. If it doesn't work on the ground, it will NOT work on the tower. The entire configuration should be plugged in and tested with the very same cables you intend to use on the tower before you haul it up. Good luck, and God speed my friend.
Oh yea, try not to get excited and yell "Lets GO, Lets GO", as we all know that this is when mistakes are made and things go wrong quickly. I know that I have a tendency to get like this, and I have to fight the internal forces that be. 
--
»www.wavecrazy.net
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