On Thu, 16 Oct 2008 22:04:20 GMT, "Jerry"
wrote:

Wow, Jeff, you are a really smart guy. It sure is nice to know that you
are able to analyze this sand over conduit problem so thoroughly.

Nope. My guesswork is far from exact. Close enough.

Heck, I
thought the air would blow out thru the sand. I didnt even consider the
sand above the air leak to be immovable.

It is immovable, until it moves. That's the real problem. We can
consider the sand to be a solid plug until it starts to break up. As
soon as that happens, it leaks like a sieve. As soon as it starts
leaking, the air pressure available for lifting the sand is
dissipated, resulting in the collapse of the sand pile. Think of it
like a real volcano. As soon as the volcano stops erupting and
belching gasses, the eruption column of airborne rock collapses, heads
for the ground, and creates a messy pyroplastic flow.

I thought the air would find a
path to leak out somewhere between the tape and the conduit.

There's plenty of opportunities for air leaks. If the PVC joints
aren't glued, the air pressure will probably separate the lengths of
PVC pipe.

I hadnt
thought about using neighbor kids.

Anyone that uses 3/4" PVC for antenna conduit, and then buries and
loses one end, is certainly not a professional underground
construction contractor. He certainly isn't going to use high prices
professional union ditch diggers. The cheapest alternative are the
neighbors kids. I currently have a horde of them working on removing
the blackberries from my hillside. It may take months and result in a
few non-fatal injuries, but it's still cheaper than hiring a landscape
contractor. Also, more fun to watch.

Why would you consider using kids for
this project?

They work cheaply. They're familiar with playing in the sand using
shovels and pails. Just tell them it's kinda like at the beach. They
also bounce instead of break at a young age, which makes them suitable
for dangerous tasks.

I'll assume you wont recommend the OP use water or air to locate the far
end of his conduit.

I posted some serious recommendations in previous rants. I like
dropping a boson's whistle down the pipe at the end of a small
diameter air hose. Apply air pressure and it should be hear through a
foot of sand. If not, it will surely scare the gophers, which might
be useful.

Jerry KD6JDJ


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