Ed wrote:

I know this is slightly off topic, but since I am intending to run
some RF cable in the conduit, and since there are a lot of intelligent
hams on this group, I will proceed anyway:

Last year at the beginning of construction of a new house I buried
about 50 feet of 3/4" Sched. 40 PVD between the house and a location on
the property perimeter. Now that I am ready to use it, I can not
locate the perimeter end.... it is somewhere in about a 10' area, and the
end curves up to probably about a foot underground.

The ground is nearly pure sand, and is well landscaped now to the
point that I do not want to randomly dig it up.

The end terminated in an elbow curving up and is well duct taped
shut.

Can anyone suggest a method or equipment I might use to locate that
far end?

Tnx.

Ed K7AAT

Ed;

Run a metal snake into the conduit then get a metal detector and sweep
the area for the conduit. If this doesn't work there are wire tracing
detectors that might do the job. You hook the transmitter to the snake
and sweep with the detector.
If all fails you might try a metal probe. Stick the probe into the
ground and feel for the conduit. Or dig up a couple of feet of conduit.
Note the direction it is going then move in that direction and dig a
small trench where you thing the conduit is.
One of these methods should work.
If all fails install new conduit.

Dave WD9BDZ

A suggestion for other folks who will be burying a conduit: Take a bunch
of pictures before the trench is filled. It's good to include distances
to some fixed reference points -- you can write them with a marker on
big pieces of paper laid on the ground to get them in the picture. I
haven't yet used the pictures I took of mine, but I sure have made a lot
of use of the pictures I took of the uncovered walls of a home addition,
showing the locations of all the studs and wiring.

Roy Lewallen, W7EL

Roy Lewallen wrote in news:I8WdnRs5
streetonline:

A suggestion for other folks who will be burying a conduit: Take a
bunch
of pictures before the trench is filled. It's good to include distances
to some fixed reference points -- you can write them with a marker on
big pieces of paper laid on the ground to get them in the picture. I
haven't yet used the pictures I took of mine, but I sure have made a
lot
of use of the pictures I took of the uncovered walls of a home
addition,
showing the locations of all the studs and wiring.

Roy Lewallen, W7EL


Damn ! NOW you tell me ! :^)

actually, I did take a gazillion pictures of the house construction
and from foundation, through all framing, to completion... but I
neglected the outside !

Ed K7AAT

On Oct 15, 2:28*am, Roy Lewallen wrote:
A suggestion for other folks who will be burying a conduit: Take a bunch
of pictures before the trench is filled. It's good to include distances
to some fixed reference points -- you can write them with a marker on
big pieces of paper laid on the ground to get them in the picture. I
haven't yet used the pictures I took of mine, but I sure have made a lot
of use of the pictures I took of the uncovered walls of a home addition,
showing the locations of all the studs and wiring.

Roy Lewallen, W7EL

We always do this at work and lately started doing GPS surveys of new
buried cables marking GPS and survey data on the pictures, This comes
in real handy when you are paying for 4 guys and a rented backhoe to
stand around and wait for you to find a cable,


Jimmie

Run a metal snake into the conduit then get a metal detector and sweep
the area for the conduit. If this doesn't work there are wire tracing
detectors that might do the job. You hook the transmitter to the snake
and sweep with the detector.
If all fails you might try a metal probe. Stick the probe into the
ground and feel for the conduit. Or dig up a couple of feet of
conduit. Note the direction it is going then move in that direction
and dig a small trench where you thing the conduit is.
One of these methods should work.
If all fails install new conduit.

Dave WD9BDZ


Dave, your idea above, plus some comments from others has made me
realize that this is the way I should proceed, for my first attempt. I
do have a Service Monitor. I'll simply run my snake into the empty pvc
conduit until it hits the end ( duct tape ) and connect an RF signal to
it, then using a small HT, track the signal down to the end.

My thanks to all for other ideas presented here, too.


Ed K7AAT

Ed wrote:
Run a metal snake into the conduit then get a metal detector and sweep
the area for the conduit. If this doesn't work there are wire tracing
detectors that might do the job. You hook the transmitter to the snake
and sweep with the detector.
If all fails you might try a metal probe. Stick the probe into the
ground and feel for the conduit. Or dig up a couple of feet of
conduit. Note the direction it is going then move in that direction
and dig a small trench where you thing the conduit is.
One of these methods should work.
If all fails install new conduit.

Dave WD9BDZ


Dave, your idea above, plus some comments from others has made me
realize that this is the way I should proceed, for my first attempt. I
do have a Service Monitor. I'll simply run my snake into the empty pvc
conduit until it hits the end ( duct tape ) and connect an RF signal to
it, then using a small HT, track the signal down to the end.

My thanks to all for other ideas presented here, too.


Ed K7AAT


Ed;

Thanks for the compliment. I wish you luck and envy you for your acreage
for antenna's. My lot here in St. Louis is something like 40 feet by
120 feet with the house in the center. I do have some trees along the
back alley that I have wire hanging from. Works but not optimal.
Let us know how everything works out.

Dave WD9BDZ

Plumbers power snake for sewers... Rent it at the rent it shop... It
will auger up through that duct tape and sand like it is tissue
paper...

denny/ k8do

On Thu, 16 Oct 2008 06:36:34 -0700 (PDT), Denny
wrote:

Plumbers power snake for sewers... Rent it at the rent it shop... It
will auger up through that duct tape and sand like it is tissue
paper...

denny/ k8do

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
can probably also do some real damage to the PVC. A much smaller
diameter "snake" is probably safer. With only 1ft of sand to push
through, a solid "tape" type electricians snake can be pushed through
by hand. The only down side is that the pipe will fill with sand when
the duct tape is breached, so cleanup may be a problem. If dry sand,
a small hose on the end of a vacuum cleaner should work.

Incidentally, the frequencies used by commerical cable finders are
815Hz, 8Khz, and 82KHz at 2-3 watts.
http://www.rycominstruments.com/3-8879-Cable-Utility-Locator.asp
However, that's good for 15 ft depth and many miles of cable. Higher
frequencies will probably work for 1ft of sand and only 100ft of wire.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

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.

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