coax question

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DewAddict

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If I was going to bury some coax in my back yard after an antenna installation, how deep should I go and what type of coax is rated for this application. Also, should I enclose it in PVC?

Thanks,

Rob
 

KC8JPZ

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A PVC conduit should work fine for you. You may want to buy a little larger conduit for future runs also. As far as depth, that's probably more of a judgement call for you to figure out. I am going to bury a line through my yard in a few weeks to the shed. I am running a 3 inch PVC conduit about 2 feet deep for 7/8" Eupen. Its only about 50' and nothing else is burried in the yard(I hope).
 

DewAddict

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Ok great!! Thanks for the info.

If I get "caught" digging a large hole in my back yard, or a neighbor calls on me, does it require some sort of city permit that you know of? I know each city is different but wanted to ask.
 

tneff

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I cant see where you would need any type of a permit , your not doing electrical work. If your putting up an antenna mast , you might want to consult just to avoid any possible issues especially if your in a zoned or deed restricted area.
 

cristisphoto

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Okay Now I have a half question half comment
Wouldn't one be concerned of Rust etc due to rain and inclement weather...
Unless you used a special PVC and sealed it all in properly...:roll:

Anyways
I live in city in a apartment hence the above is merely specualtion LOL

Crista
 

KC8JPZ

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Good question Christa. Rust should not be an issue do to the conduit being made of PVC. Yes, a good PVC cement is used to seal the conduit. I am using conduit that has a bell on one end which slides over the the next section of conduit. The one end of my coax is coming out of the ground inside my shed so no moisture will be able to enter that way. Where it comes out of the house is stubbed up above the ground about a foot and a half into a big weather resistant box which is secured against the house and where the line comes out of the house.

http://www.lowes.com/lowes/lkn?action=productDetail&productId=72819-223-49013&lpage=none

the box I am using is simmilar to this. about 16"x16"x 6.5" deep
http://www.hammondmfg.com/R130OB.jpg
 

red8

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I don't believe I would use PVC piping as a conduit underground due to the durability issues (i.e. rodents) burrowing underneath. It's an
apples and oranges deal like everything else in life pros and cons
which is cost effective ?
 

W4KRR

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red8 said:
I don't believe I would use PVC piping as a conduit underground due to the durability issues (i.e. rodents) burrowing underneath. It's an
apples and oranges deal like everything else in life pros and cons
which is cost effective ?

Our highway lighting systems use PVC conduit buried three feet down with no problems. We use it for runs of hundreds of feet. It's usually schedule 40, two inches in diameter. The only place we use steel conduit is where the run passes under a roadway. PVC should be fine for the use mentioned here, likely something smaller than two inch pipe.
 

jim202

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I guess you haven't been to a construction site recently. Just about
all conduit placed in the ground these days is PCV. They use it for
everything, electrical, cable TV, telephone water, the list goes on.

Only comment I will pass along is that no matter how well you seal
the PVC conduit, I have always seen water in them. It's a fact of
life, that any underground conduit will get moisture and or water in
it at some point. It always amazed me when doing work around the
New Orleans area just how much water would get into all the
underground conduit.

Jim



red8 said:
I don't believe I would use PVC piping as a conduit underground due to the durability issues (i.e. rodents) burrowing underneath. It's an
apples and oranges deal like everything else in life pros and cons
which is cost effective ?
 

kf4lne

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The grey PVC conduit is made to be buried. if you seal it really well using PVC glue and let the glue cure you should have no water leak issues. The way you do this is to use a good cleaner, prep the conduit ends, apply a liberal amount of glue and when you put the ends together give it a 1/2 turn twist so it spreads the glue around to get a solid seal. I suggest using the blue glue since its meade to be used in moist enviroments and sets up really well. You can also use schedule 40 3/4 inch water line for this, like the stuff used to supply water to the house from the well or water meter. When you get the PVC in place let it set over night before you pull your coax through it. To make it easire to pull the coax you can put baby powder in the pipe to use as a lubricant to help the coax slide through easier. Its not a hard thing to do and if done correctly you shouldnt have any leaks or any problems.
 

tonsoffun

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The grey PVC conduit is what I used on the tilt-over and is made for this application. I also used this PVC to run electricial wire to my shed.
Here is some pics:
100_1199.jpg

100_1201.jpg

100_1200.jpg

Take care
 

KC8JPZ

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Once again, Ron has some great pictures of great installation. My setup is going to be near identical to that.Only, I don't need the weather head because of it coming up into my shed. I am going to mount a small box on the back of the shed for the 7/8 to terminate into and that will give me a place to connect temporarily for some of my homebrew project antennas. As for durability of sched 40 PVC. You will find it is much harder to damge than you may think. It really is used for almost everything anymore.Also, when you go to put your bends or elbows on, try to make that radius as large as possible if you are using a hot box. Sounds like you may using a smaller coax though so that shouldn't be much of an issue.
 
N

N_Jay

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OK< lets all chime in with more good and bad information mixed together.:roll: :roll: :roll:

Underground conduit is a WET location by definition.

Even if perfectly sealed for the length underground it will accumulate water due to condensation.

Any cable in underground conduit should be rated for WET locations. Most coax is NOT!

Better yet, it should be rated for direct burial, in which case you don't need the conduit unless you want extra protection or to make replacement easier.

Now, everyone who THINKS they KNOW WHAT THEY KNOW, rather than KNOWING what the DON'T KNOW can start arguing with me.:twisted: :lol: :twisted:
 

tonsoffun

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N_Jay said:
OK< lets all chime in with more good and bad information mixed together.:roll: :roll: :roll:

Underground conduit is a WET location by definition.

Even if perfectly sealed for the length underground it will accumulate water due to condensation.

Any cable in underground conduit should be rated for WET locations. Most coax is NOT!

Better yet, it should be rated for direct burial, in which case you don't need the conduit unless you want extra protection or to make replacement easier.

Now, everyone who THINKS they KNOW WHAT THEY KNOW, rather than KNOWING what the DON'T KNOW can start arguing with me.:twisted: :lol: :twisted:


Good point N Jay
I forgot to mention this. The coax I have going through the conduit is Direct burial.
LMR-400DB and RG-6 Direct burial. The conduit makes it easy to pull new cable in and or out.
 

gcgrotz

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Right N_Jay. Use cable rated for direct bury. I have about 65ft of 1-1/2inch pvc running to my shed with direct bury rated RG213. While I was at it I buried below the conduit some 1-1/2 inch copper strap and connected it to the antenna ground rod at the shed and the house main ground rod at the other end. I plan to dig in a few radials when I get the HF antenna installed in the back yard.

We bury everything in PVC in my world (Cellular/pcs base stations) including CAT5 wire. Some of it gets wet. I have a theory that condensation inside the pipe plays a part in that as well.

One other thing - unless you are hand digging the trench I would call miss utility if there is ANY shadow of a doubt of something else being buried there. Its free and covers you if you do hit something you wont get charged for the repair by the utility.
 

E-Man

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Even if you are hand digging, its a good idea to call Miss Dig (MI) 1-800-Missdig.
 

car2back

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E-Man said:
Even if you are hand digging, its a good idea to call Miss Dig (MI) 1-800-Missdig.


lol, It's "Call OKIE" here. I would recommend you call what ever number you have locally before digging for any reason.
 

cristisphoto

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KC8JPZ said:
Good question Christa. Rust should not be an issue do to the conduit being made of PVC. Yes, a good PVC cement is used to seal the conduit. I am using conduit that has a bell on one end which slides over the the next section of conduit. The one end of my coax is coming out of the ground inside my shed so no moisture will be able to enter that way. Where it comes out of the house is stubbed up above the ground about a foot and a half into a big weather resistant box which is secured against the house and where the line comes out of the house.


Thanlks!
NOw once I move back east then I can have some idea for my setups
LOL
Warmest regrads
Crista
 
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