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

On Thu, 16 Oct 2008 21:53:20 -0700, Jeff Liebermann
wrote:

Plug up the other end with whatever is handy. Blow
air into the center of the tube. Run your fingers around the edges of
the tube and note which way the air is flowing. That's what will
happen if the compressed air is not sufficient to blow 30 lbs of sand
into the air. The air and the sand will flow back into the pipe in
the opposite direction as the compressed air.

Hi Jeff,

Well, it's been a coon's age since I've seen vacuum cleaners that
would let me attach to their exhaust - so that's out.

As for driving compressed air into a short (or open). I've done that,
but not for sand excavation. Rather, I've used what was commercially
called the "vortex effect" which separates the two air current flows
you allude to above to create a hot stream and a chilled stream of
air. (Elevated or depressed from the average of the inlet
temperature.) I used this for cooling electronics in a paper mill.
Not particularly efficient, but compressed air was available, and the
VorTec nozzle was a quick and easy solution to their NEMA enclosures.

See:
http://www.vortec.com/support_casestudies.php
or
https://secure.vortec.com/store_prod...tID=9&prodID=6

This, and some of my fluidic applications constitute a specialized
niche in alternative logic systems. Notably, they all work off
principles of reflected power that demonstrate palpable examples.

73's
Richard Clark, KB7QHC

Richard Clark wrote:

Well, it's been a coon's age since I've seen vacuum cleaners that
would let me attach to their exhaust - so that's out.

Have you ever heard of a shop vacuum?

Usually only available at highly specialized stores such as Walmart.


--
Jim Pennino

Remove .spam.sux to reply.

On Fri, 17 Oct 2008 06:05:01 GMT, wrote:

Richard Clark wrote:

Well, it's been a coon's age since I've seen vacuum cleaners that
would let me attach to their exhaust - so that's out.

Have you ever heard of a shop vacuum?

Usually only available at highly specialized stores such as Walmart.

Hi Jim,

Unfortunately my shopping nature turns me more towards Fry's and I
certainly have very little interest in yet another vacuum cleaner (if
they offer them). Market forces long (decades) ago convinced me that
Hardware skills were in a declining employment segment in proportion
to software.

There may not be a software solution to this current problem of
locating a buried pipe, but I wouldn't have buried it without some
simple binary marker (it's here!). The analog solutions offered are
inventive, and I do appreciate them however. One or several are
probably far more effective than going to Walmart for a shop-vac (that
would only become a permanent altar attesting to my need to use it in
justification for its expense).

73's
Richard Clark, KB7QHC

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

On Thu, 16 Oct 2008 22:26:10 -0700, Richard Clark
wrote:

Well, it's been a coon's age since I've seen vacuum cleaners that
would let me attach to their exhaust - so that's out.

The problem with vacuum cleaners is that they all suck. I have an
ancient Electrolux and a Shop Vac that both have usable exhaust ports.
I also have a Hoover upright and a Hoover cannister in the office that
do not. Y'er right that it's a vanishing breed.

However, you re-read what I scribbled, you might notice that I
suggested that one use the air compressor to pressurize the 3/4" PVC
pipe. That's because the average vacuum cleaner can barely generate
more than a few PSI. They also leak badly. If you're trying to lift
a column of sand or demonstrate backpressure, it's much easier with a
proper air compressor.

As for driving compressed air into a short (or open). I've done that,
but not for sand excavation.

I have. The clumsy backhoe operator (me) once dropped a load of dirt
on top of the steel 3" conduit end during construction. I'm also the
idiot that forgot to shove a protective rag into the conduit end. I
spent the next two days trying to figure out how to get the dirt out
of the pipe. I eventually fabricated a cylinder shaped rubber plug
with an eyebolt down the center, dumped some water into the conduit,
and dragged the plug through the pipe with a winch. It took about 5
passes for the water to come out clear. I then pumped out the
remaining water, dragged a sponge through the pipe a few dozen times,
and then let evaporation do the final cleanup. Compressed air was
attempted just for fun, but it was obvious that it wasn't going to
lift the dirt out of the pipe.

Rather, I've used what was commercially
called the "vortex effect" which separates the two air current flows
you allude to above to create a hot stream and a chilled stream of
air. (Elevated or depressed from the average of the inlet
temperature.) I used this for cooling electronics in a paper mill.
Not particularly efficient, but compressed air was available, and the
VorTec nozzle was a quick and easy solution to their NEMA enclosures.

See:
http://www.vortec.com/support_casestudies.php
or
https://secure.vortec.com/store_prod...tID=9&prodID=6

Nice. I built several out of the original Amateur Scientist book
(which I still have on my bookshelf) in the early 1960's. It worked
amazingly well. Much later, I built one out of PVC pipe, which
melted. Now I know why they're made out of metal. Never mind the
inefficiency. It's the noise they make that drives me nuts. At one
point, we had 4 of them in series, with 4 assorted air compressors
pumping about 4 SCFM into each, and got it down to about -100C. We
started with a group of about 10 lab students, and ended up with a
crowd of about 100 nosey students wondering why someone was trying to
operate a jet engine on campus.

This, and some of my fluidic applications constitute a specialized
niche in alternative logic systems. Notably, they all work off
principles of reflected power that demonstrate palpable examples.

I'll pass. I don't believe in logic any more. Everything can be
explained in terms of politics, psychology, and conspriacies. Logic
is obsolete.


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

On Fri, 17 Oct 2008 06:02:04 -0700, Jeff Liebermann
wrote:

However, you re-read what I scribbled, you might notice that I
suggested that one use the air compressor to pressurize the 3/4" PVC
pipe.

Hi Jeff,

I was responding to the broad assortment of methods which included
what was the closest option for me of a vacuum cleaner.

That's because the average vacuum cleaner can barely generate
more than a few PSI. They also leak badly. If you're trying to lift
a column of sand or demonstrate backpressure, it's much easier with a
proper air compressor.

No doubt and no argument. At one point in my career, I found myself
with a dead weight tester, calibrating a pressure gauge to 10,000 PSI
when the coupling line spit sending a fine spray of pressurized oil
past my face. Took me half an hour to shake off the thought of it
hitting me square.

As for driving compressed air into a short (or open). I've done that,
but not for sand excavation.

I have. The clumsy backhoe operator (me) once dropped a load of dirt
on top of the steel 3" conduit end during construction. I'm also the
idiot that forgot to shove a protective rag into the conduit end. I
spent the next two days trying to figure out how to get the dirt out
of the pipe. I eventually fabricated a cylinder shaped rubber plug
with an eyebolt down the center, dumped some water into the conduit,
and dragged the plug through the pipe with a winch. It took about 5
passes for the water to come out clear. I then pumped out the
remaining water, dragged a sponge through the pipe a few dozen times,
and then let evaporation do the final cleanup. Compressed air was
attempted just for fun, but it was obvious that it wasn't going to
lift the dirt out of the pipe.

I've done that too. For a summer of my youth (when dinosaurs ruled
the earth) I would plunge down a manhole with a tethered ball. I'd
plug it into the downhill side, clamber out, and fill the manhole with
water. Then go to the next manhole, clamber down and dig out all the
muck that had been plunged ahead of the tether ball. Repeat for
weeks.

Substituting one central phrase of "Apocalypse Now":
"The aroma of it all! The AROMA of it all!"

I'll pass. I don't believe in logic any more. Everything can be
explained in terms of politics, psychology, and conspriacies. Logic
is obsolete.

Last night I went to a reception for Joseph Stiglitz where he
mentioned being a liberal too much (he was apologizing to the group at
that point) and I drew him aside to comment that he had no need to
explain his bias as this was the first time in our political history
when we had two candidates BOTH running against the administration AND
the Republican Party. We laughed at that logic.

73's
Richard Clark, KB7QHC

Richard Clark wrote:
On Fri, 17 Oct 2008 06:05:01 GMT, wrote:

Richard Clark wrote:

Well, it's been a coon's age since I've seen vacuum cleaners that
would let me attach to their exhaust - so that's out.

Have you ever heard of a shop vacuum?

Usually only available at highly specialized stores such as Walmart.

Hi Jim,

Unfortunately my shopping nature turns me more towards Fry's and I
certainly have very little interest in yet another vacuum cleaner (if
they offer them). Market forces long (decades) ago convinced me that
Hardware skills were in a declining employment segment in proportion
to software.

There may not be a software solution to this current problem of
locating a buried pipe, but I wouldn't have buried it without some
simple binary marker (it's here!). The analog solutions offered are
inventive, and I do appreciate them however. One or several are
probably far more effective than going to Walmart for a shop-vac (that
would only become a permanent altar attesting to my need to use it in
justification for its expense).

73's
Richard Clark, KB7QHC

Everyone needs a shop vac, especially a wet and dry one.

Unless you really like spending a long time mopping floors.


--
Jim Pennino

Remove .spam.sux to reply.

On Fri, 17 Oct 2008 16:35:02 GMT, wrote:

Everyone needs a shop vac, especially a wet and dry one.

Unless you really like spending a long time mopping floors.

I was once a swab jockey. Mind? when there was no choice you turn
that off.

Hi Jim,

I prefer dry floors. That's why I invested in a French drain. And I
have more floor space than that which would have been lost to a barrel
that sucks.

73's
Richard Clark, KB7QHC

On Fri, 17 Oct 2008 09:19:00 -0700, Richard Clark
wrote:

At one point in my career, I found myself
with a dead weight tester, calibrating a pressure gauge to 10,000 PSI
when the coupling line spit sending a fine spray of pressurized oil
past my face. Took me half an hour to shake off the thought of it
hitting me square.

Ouch. At that pressure, the first few drops of oil will give you an
instant tattoo. An acquaintance recently had that happen to him. He's
now recovering from the skin grafts and laser ablative cleanup.

The closest I came to that was getting a hydraulic fluid shower while
riding as an operator inside a Rose Float (in about 1968). The floats
animation was run by a pony engine and hydraulic pumps. The coupling
directly over me started to leak. After 2 hours in the float
lumbering through Pasadena, I arrived thoroughly soaked.
http://802.11junk.com/jeffl/pics/jeffl/slides/RoseFloat01.html
That's me testing the chair position (which was arc welded in place so
it had to be perfect). My feet are resting on top of the electrical
animation switching panel.

For a summer of my youth (when dinosaurs ruled
the earth) I would plunge down a manhole with a tethered ball. I'd
plug it into the downhill side, clamber out, and fill the manhole with
water. Then go to the next manhole, clamber down and dig out all the
muck that had been plunged ahead of the tether ball. Repeat for
weeks.

Well, I missed such fun when I was younger. I worked for the same
monopoly. While you were playing in the muck, I was "re-enforcing"
100 pair bundles and working in the battery room.

Substituting one central phrase of "Apocalypse Now":
"The aroma of it all! The AROMA of it all!"

These days, the installers doing FTTS (Fiber Through the Sewers) have
all the fun. Instead of summer interns, the dirty work is done by a
robot which installs a SAM (sewer access module):
http://www.kate-pmo.ch/pages/en/fast.html
Despite the robotics and improved handling, the packets delivered
still seem to smell of effluvia.

... as this was the first time in our political history
when we had two candidates BOTH running against the administration AND
the Republican Party. We laughed at that logic.

Chuckle. Very true. Worse, the "real" agendas of both parties are
almost identical. I noticed that both parties are also against the
status quo (which is generally considered awful). That makes me
wonder just what they are in favor of actually doing. I would prefer
they do absolutely nothing and let the economy fix itself, but that's
too much to hope for. Let the lesser evil win in Nov and never mind
trying to decode their logic.

I should feel guilty for encouraging this off topic discussion,
complete with topic drift, but I don't.



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