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Re: [TowerTalk] Sealing cables at PVC exit?

To: <TOWERTALK@contesting.com>
Subject: Re: [TowerTalk] Sealing cables at PVC exit?
From: "K8RI on Tower talk" <k8ri-tower@charter.net>
Date: Sun, 16 Jul 2006 00:16:47 -0400
List-post: <mailto:towertalk@contesting.com>


> Ed:
>
>     My first suggestion to you:  Use 4 inch conduit if possible.  I used 
> three inch because that was the max width hole my DitchWitch (tm) would 
> cut for me.  I should have at least tried to sink 4 inch PVC into the 
> hole, but too late now.

Unless running large coax and lots of them you will probably find the 3" to 
be sufficient.  I used 3" with 5 runs of LMR400, 4 of RG-6, large rotator 
control cable, and the control cable to the remote coax switch.

>
>     Second suggestion:  I think you left off the word <not> in front of 
> <making> or in front of <a good idea> in your e-mail, below.  You do NOT 
> want to glue the elbows to the vertical PVC.

As I have a permanent instalation with pull boxes at each end it is *all* 
glued. <:-)) IF it weren't for the joints that didn't seat properly I'd be 
able to *push* even the RG-6 in the full 80 feet or so, but as it is I use a 
fish tape and a 3/16" nylon rope.

When we put the conduit in for the house electrical system feed (also 3") 
and for the cable company (1/2") I put a 3/16 nylon pull cable in each.

>
>     Yes, I also installed a pull rope for future use in the conduit. 
> Essentially, I pulled it along with the last coax cable through the 
> conduit.

I try to remember to do that with each coax and then the next one is easy to 
install.

>
>     Finally, you ought to drill a few half-inch diameter holes in the 
> undersides of the low spots in your PVC

I think you will find that 1/8" will be plenty and unlike the 1/2", sand 
will not tend to work up into the conduit and if they find them, mice fit 
easily through 1/2" holes.  Speaking of that, as I sat here typing last 
night I felt something start crawling up my left arm. It felt like a spider 
but then I feld that wet, cold nose of my cat. (First time he did that I 
darn near threw the keyboard into the ceiling fan) He trilled a couple of 
times so I knew he wanted something. When I turned around he was sitting 
there proudly and presneted me with fresh food.  Critters that get into this 
house do not last long plus I let him out to hunt for a couple hours per 
day.  BTW our bird feeders are now about 7' off the ground. It was either 
raise them or start calling them cat feeders.

>run.  This will allow any accumulated water (and there WILL be some) to 
>drain into the earth below.  You >can also dig a small pit underneath these 
>PVC holes and fill the pits with gravel to act as a drain field.  You >keep 
>the critters out of these holes by wrapping them (the holes, not the 
>critters)  in landscape cloth and >securing the cloth with wire ties around 
>the PVC.

Another reason for keeping the holes to 1/8" or 1/16". No extra work to keep 
the critters out...well except for ants. Unless in clay or very heavy loam 
there is no need to dig extra drainage.  Unless you specifically create a 
low spot water will tend to find the almost invisible low spots. (good idea 
to make a low spot and it only need to be low enough so the rest of the 
conduit will drain to those drain holes)  The 1/8" is plenty large enough. 
Here, nothing drains in the winter as the conduit is above the frost line.


Roger Halstead (K8RI and ARRL 40 year Life Member)
N833R - World's oldest Debonair CD-2
www.rogerhalstead.com
>
>
> Gil:
>
>     You keep the critters out of the ends of the PVC by plugging the ends 
> with some pliable material like fiberglass insulation or that expanding 
> foam stuff.  I've used fiberglass insulation because the critters around 
> these parts don't seem to have an appetite for it and it's a lot easier to 
> remove for future cable installation.



>
>
>     I'll probably think of a few more things on this subject.
>
> 73 de
> Gene Smar  AD3F
>
>
> -------------- Original message ----------------------
> From: Edward Sylvester <navydude1962@yahoo.com>
>> Interesting stuff from the group!  I am planning my own installation and 
>> this
>> has been very helpful.  I agree that making the "elbow" permanently 
>> affixed is a
>> good idea.
>>
>>   Question I have is, did any of you run a length or two of rope for 
>> future
>> cable pulling?  My PVC, from shack to tower, will be about 25' in length 
>> and
>> buried under cement, so this won't be very accessible.
>>
>>   Your suggestions are most welcomed.
>>
>>   73,
>>   Ed NI6S
>>
>> "Richard M. Gillingham" <rmoodyg@bellsouth.net> wrote:
>>   I like it.
>>
>> How do you keep the kritters out?
>>
>> 73
>> Gil, W1RG
>> ----- Original Message ----- 
>> From: "JC Smith"
>> To: ;
>> ;
>> Cc: "'Paul Ferguson'"
>>
>> Sent: Saturday, July 15, 2006 4:18 PM
>> Subject: Re: [TowerTalk] Sealing cables at PVC exit?
>>
>>
>> >I did basically the same thing but used 4" ABS. The DWV sweep fittings 
>> >are
>> > inexpensive and available at the local home center. I used a 
>> > combination
>> > of
>> > a 90 and a 45 on each end, and as Gene says, don't glue them on the 
>> > pipe.
>> > It makes pulling the cable much easier. Here's a picture:
>> > http://i14.photobucket.com/albums/a317/k0hps/Misc/ABSConduit.jpg
>> >
>> > 73 - JC, K0HPS
>> >
>> >
>> > -----Original Message-----
>> > From: towertalk-bounces@contesting.com
>> > [mailto:towertalk-bounces@contesting.com]On Behalf Of 
>> > ersmar@comcast.net
>> > Sent: Saturday, July 15, 2006 10:20 AM
>> > To: Paul@PaulFerguson.us; TOWERTALK@contesting.com
>> > Cc: Paul Ferguson
>> > Subject: Re: [TowerTalk] Sealing cables at PVC exit?
>> >
>> > Paul:
>> >
>> > From your description I'm not sure exactly how your PVC is configured
>> > at each end. Assuming your PVC emerges from the ground vertically, you
>> > ought to include a PVC U-turn (two 90-degree elbows) in the end(s) so 
>> > that
>> > the cables emerge DOWNWARD. You can then use attic insulation to stuff
>> > the
>> > end(s) of the PVC U's around the cables. And don't glue these U's to 
>> > the
>> > vertical PVC; let them loose so you can remove them for easier cable
>> > pulling.
>> >
>> > This method: allows for the conduit to breathe, i.e., lets moisture
>> > evaporate to a certain extent; prevents large fauna such as mice from
>> > entering said conduit; and is easy to remove to add/remove cables in 
>> > the
>> > future.
>> >
>> > In my conduit system the ends of the 3 inch PVC's enter steel boxes at
>> > the shack and tower ends. Therefore, I don't need to include such drip
>> > loops in my PVC system. At the shack end the cables are routed from the
>> > steel box into the crawl space underneath the ground-floor shack. In 
>> > this
>> > manner the moisture from the conduit can be evacuated from the crawl 
>> > space
>> > through normal ventillation.
>> >
>> > 73 de
>> > Gene Smar AD3F
>> >
>> >
>> > -------------- Original message ----------------------
>> > From: "Paul Ferguson"
>>
>> >> I am using buried 4-inch PVC pipe to run coax and control cables from
>> >> shack to tower base. The PVC come out of the ground, turn horizontal,
>> >> and end a foot or two above the tower base. The cables will exit the
>> >> PVC, take a small drip loop, and get routed onward.
>> >>
>> >> What is the best way to seal the end of the PVC around the cables? I
>> >> thought about using a PVC end cap and drilling holes, but adding a
>> >> future cable would be difficult. I am interested in hearing what
>> >> creative solutions others have found.
>> >>
>> >> 73,
>> >> Paul
>> >> K5ESW
>> >> _______________________________________________
>> >>
>> >>
>> >>
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