On Thu, 16 Oct 2008 16:37:22 GMT, "JB" wrote:
Ummm.... this is through 3/4" schedule 40 PVC with at least two right
angles. The augers I've seen are for much larger sewer drain pipe and
will not fit inside 3/4" PVC. Anything that can drill through sand
Ouch! Unless you are trying to fish a phone line, you (might/might
not/want) WILL dig it all up and go to 2" with 45 degree bends and bevel the
inside edges. Once above ground you can break out to pull boxes.
You have my sympathy.
Thanks for the sympathy but it's not my conduit or problem. The
plumbing belongs to Ed, K6AAT.
Question: What's the difference between conduit and plumbing?
Answer: Plumbing holds water. Otherwise, they're the same.
I'm not sure what might be going inside a 3/4" conduit, but if it's
for a tower, it's way too small. The original question does not
indicate what manner of wiring goes inside. With 3/4", you can get
perhaps one run of LMR400 plus some flat rotator cable and you're
full. Hard to tell from here.
It's also possible to place a diplexer (or triplexer) at both ends of
the single coax run for splitting out HF, VHF, and UHF. I've done
that when running multiple coax cables was impossible.
http://www.rfparts.com/diamond/Product_Catalog/plexers.html
It's been a long time since I've done any tower construction, but for
commercial installs, I never used buried coax runs. AC power for the
tower lights were in 3" steel threaded conduit (not EMT), but the coax
was all above ground. That shortened the coax runs about 25ft which
was well worth the effort.
Incidentally, a good trick is to *NOT* lay the conduit perfectly
horizontally plumb. Put one end lower than the other so that water
well drain into that end. Shove a PEX sprinkler line down to the low
point of pipe and pump out the water once a year. I prefer
pressurized conduit, but a water sump works fairly well.
I discovered, the hard way, why using steel pipe instead of PVC was a
good idea. With everything underground, the obvious parking location
for the crane, cherry picker, or propane truck was directly on top of
the buried PVC. After a few cracked pipes, I decided that steel was a
good idea.
I like to pressurize the conduit slightly to keep the water out. It's
really not necessary as most coax will survive when immersed. However,
everyone re-uses coax, which has cuts in the outer jacket, and which
might not be fully waterproof. A pressure gauge, bicycle valve,
bicycle pump, some putty, and a few PSI are good enough.
I almost forgot.... a slow death to the installer that shoved a coax
barrel splice down a stuffed conduit, thus insuring that all
subsequent coax runs will jam up against the coax connectors.
Also, this is what happens when a monopole tower is stuffed full of
coax cables, and some idiot decides to enlarge the hole with a cutting
torch.
http://802.11junk.com/jeffl/pics/drivel/slides/monopoleBurn.html
http://odessaoffice.com/wireless/priceless.jpg
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060
http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558