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Re: [TowerTalk] protective hose for COAX runs

Subject: Re: [TowerTalk] protective hose for COAX runs
From: K8RI <>
Date: Wed, 11 Apr 2012 18:40:10 -0400
List-post: <">>
On 4/11/2012 6:14 PM, Rick Karlquist wrote:
> JoshL wrote:
>> I  live in high desert of Northern NV
>> Lots of creatures are eager to chew on coax
>> or control lines .
>> I have some LMR 400 running inside some
>> FIBER optic hose ( very tough stuff) that I found
>> for free about 200 ft one piece .
>> I could use hardline too
>> *but does anyone have a source of surplus Fiber
>> Optic protective hose ? *
>> I guess flexible EMT might be use able to protect
>> coax also ?
> A general problem with hoses of whatever sort is that
> they always seem to arrive coiled up and don't want
> to lay flat on the ground.
> I have tried various ideas along these lines.  I tried
> flexible plastic conduit (called "ENT") and found that
> pulling coax through it was a big hassle, and then the
> stuff lasts only a few years in the sun before turning
> brittle and falling apart.

I use 3 and 4" PVC conduit and lots of cable pulling soap.  You want 
lots of extra space! I use 2 45's to make a sweep 90. I do not even glue 
them together.  I use DC-4  or DC-5 compound, but any silicone grease 
should work.  I'd not use organic based grease.  The grease allows the 
sections to fully seat and makes them pretty much water proof, but in 
this climate it won't prevent condensation.

I have two runs from the shop and house to the tower where they sweep up 
and into a NEMA weather proof enclosure.  The cables leave the enclosure 
through bulkhead connectors or cable compression fittings.  The conduit 
is under compression.  The photos are a bit out of date, but gives a general 
idea.  The last photo shows the use of wire soap. Use liberally along 
the entire length.  Yah, it's messy, but easy to wash off.

There are typically 3 or 4 runs of LMR-600, 3 runs of RG-6 for TV, four 
3/8" 8 conductor cables (one 6-pack, two remote coax switches, and one 
rotator control cable)
The conduit sweeps up to another NEMA box where conduit exits the back 
of the box and goes through the plate on top of the basement wall.  
(Much easier than going through concrete and easier to close.) This 
short stub is filled with expansion foam after the cables and 
installed.  That way the conduit only breathes outside and no way for 
critters to get in.  It's buried just under the sod.

> I also tried to use cheap poly irrigation tubing (5/8 inch
> diameter) as a sheath over coax, but it turned out that
> it was impossible to slip even as much as 100 feet of tubing
> over coax due to the friction, and the fact that the tubing
> wanted to curl up.

Use lots and lots of cable pulling soap.  You can put so much wire in 
steel conduit you have to have a row of guys beating on it with 
hammers,   Particularly with plastic on plastic (hose and coax) the 
cable pulling soap is not just handy, it's essential!
I can't over emphasize the *liberal* use of that cable pulling soap.  
Some places call it a lube.  Virtually all the big box stores have it 
and it's cheap.

> What has worked very well was to slip ten foot sections of
> PVC conduit over coax one at a time and connect them with
> fittings just using the friction of engagement.  It would also
> be possible to tape the joints as is done on SteppIR elements.
> This method is very easy because you are not pulling coax through a long
> conduit.  Instead you pull the conduit over the coax.  No problem even
> with 500 feet.
> In some cases I have dug a trench 2 inches deep and buried
> these runs just deep enough to avoid tripping over them.

The trench is a good idea even if to just protect the contents from UV.


Roger (K8RI)


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