<snip>
>>
>> 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.
>>
>
>
> I guess the size of the conduit depends on how many right-angle pulls you
> go through, in addition to the
Agreed.
>number of cables. Most folks in the bidness (outside plant construction)
>recommend no more than four 90's >in any conduit run, to minimize the
>crushing force applied to the cables under tension in the conduits during
> >pulling. In my case, the conduit system is only fifty feet from the
>shack, but it includes three 90's (in three
Here the conduit is about 80 feet long. There is so little resistance you
could push the coax through even with 4 cables already in there. The only
problem is some of the joints did not fully seat and that left some
shoulders that can catch the end of a cable. Wraping them with tape to give
a tapered end works pretty well, but the pull cable works very well and
requires suprisingly little force so I'm not worried about crushing forces.
>dimensions) and one 45. And that's after I remove the non-glued elbows at
>the tower's steel box. Still wish I >had gone to four inch PVC, though.
4" certainly would have reduced any pulling forces.
>
>
>> >
>> > 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.
>
>
>
> I think I decided on the larger hole size so that I could ream out the
> inside of the opening a bit to remove the >bits of sharp plastic left
> after drilling. If you drill small holes, they'll also have these sharp
> edges, but you >won't
A good sharp bit should leave lttle sticking in. If it is a problem, follow
the initial bit with one a single size larger and hold it back so it goes
through slow. It'll clean the hole and any edges or bits that may have
popped up on the inside. If need be you can also "tilt" the bit and move
the drill motor in a circle which will give you a cone shaped hole on the
inside if done right. Even if you get a cone shape on both the inside and
outside is still fine. For me the most difficult was getting the low spot
where I wanted it to make sure there would be no water collecting (and
staying) in the conduit.
>be able to remove them, depending on where they are in the PVC (near the
>end vs in the middle). I was >concerned that I might snag the coax or
>control cable jackets on this sharp stuff and effectively breach the
Which is a good valid concern. If sharp edges are created they can breach
the jacket. I've never had a problem with internal sharp edges, but I have
had the end of the stub coming down out of the pull box strip off a piece of
insulation. It now has a rounded edge. They make commercial (edges?) pieces
that glue on the end of the conduit to protect the cables from the sharp
edges which I now have installed both inside and out.
Wind moving the cables at the base of the tower also have caused wear, but
no perferations in the jackets and I'll swear there is nothing the cables
can touch down there.
73 and good luck,
Roger Halstead (K8RI and ARRL 40 year Life Member)
N833R - World's oldest Debonair CD-2
www.rogerhalstead.com
>insulation. The landscape material is supposed to keep out the critters
>from these holes, while allowing >accumulated water to drain.
>
>
>
>>Unless in clay or very heavy loam
>
>
> ....That's what I have here in the DC area.
>
>
>
>>
>>
>> Roger Halstead (K8RI and ARRL 40 year Life Member)
>> N833R - World's oldest Debonair CD-2
>> www.rogerhalstead.com
>> >
>> >
>
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