> 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
I agree the conduit opening should be pointed *down*.
I use "sweep" 90s, or "sweep" 45s but I do have cable pulling boxes at each
end. One important thing with conduit; make certain all permanent joints
are fully seated. If not it leaves 1/4" to 3/8" sharp shoulders inside which
may make pushing a snake or cable through difficult.
With 3 or 4" conduit, use *lots* of "wire pulling" soap. It's messy but well
worth the mess. I ended up getting caught short on that stuff so I used
plain old *mild* dish washing soap undiluted. With a little electrical tape
on the end cable so it's not squared off plus a bit of soap, I can "push" a
run of LMR-400, or even RG-6 all the way through the roughtly 80 feet of
conduit and that includes two sweep 90s and a pair of sweep 45s used to make
a long 90.
> 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
> 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.
Conduit does need to be able to breathe, but it also needs a way to drain
Witht he soaft foam I use it can breathe, but I still need a couple of very
small holes in the bottom of the conduit at the low point.
I did include a link showing the conduit run from the tower tohouse, but I
did it a bit different in my shop.
http://www.rogerhalstead.com/ham_files/boatanch.htm The bottom 4 photos
on the page show the coax routing into the shop as well as the 1 1/2" steel
conduit run through the shop to the antique as well as the portable station.
The Cat5e network cable comes in through the south wall just to the left of
the desk supporting the radio station.
BTW we have a devil of a time with paper wasps building nests in just about
every available nook and crany. I noticed I had to swat a bunch of them
when I went out to my wife's old car. Then I discovered they had build
nests at the front and rear of the driver's door (In that space between the
door and frame). No wonder I was so busy. I purchase and use the Wasp and
Hornet killer by the case. They managed to get under the siding on the
south end of the house up near the peak of the roof. They built a nest so
large they popped the siding off.
So far I've found the fiberglass insulation has to be stuffed in really
tight to keep them out and the soft foam is the easiest way of keeping them
out of the conduit. Make a chunk of the stuff and let it harden. It's quite
porous. Give it a couple of shots of insect spray. I have a chunk of the
stuff in each box at the end of the house to tower run. Since doing that I
have not found a singel bee in there.
Currently the stub coming down from the box on the tower is open as I'm
doing a lot of tower work at present...excpet for today. It's way too *HOT*
out there. It's supposed to get hot tomorrow.
Roger Halstead (K8RI and ARRL 40 year Life Member)
N833R - World's oldest Debonair CD-2
> 73 de
> Gene Smar AD3F
> -------------- Original message ----------------------
> From: "Paul Ferguson" <Paul@PaulFerguson.us>
>> 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.
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