Isn't the LMR400 rated for direct burial? Certainly there are varieties of
RG8 that are. If you don't use a conduit type thing, you do not have to
worry about water accumulation, because the cable and ground will eventually
dry out between rain storms, unless you bury it deep.

Tam/WB2TT
"yea right" wrote in message
news
I would like to bury my coax for a distance of about 20ft. The location
consist of 6" of crushed decorative rocks over the top of very rocky soil.

I intend to take the LMR-400 coax and push it through a garden hose to add
a layer of protection. However, I am worried that condensation will
quickly fill the airspace of the hose with water and it will either
penetrate the coax outer jacket or interfere with the performance of it in
some unknown negative way.

I can not flood the garden hose with petroleum oil as it will soon eat
through the PVC jacket of the coax or garden hose. Ideally, I would like
to flood the hose with the same stuff they put into underground cables. It
has a honey consistency and is not easily displaced by water. I was hoping
for some type of silicon oil but am unable to find anything similar at the
hardware store.

Anybody have any suggestions?

On Sat, 18 Oct 2003 21:18:02 GMT, helmsman
wrote:

yea right wrote:

I would like to bury my coax for a distance of about 20ft. The location
consist of 6" of crushed decorative rocks over the top of very rocky soil.
SNIP
Anybody have any suggestions?

I can't find the original post, and going to Google to get it would be
starting another thread, soooo,,,, I'm just going to insert here.

The answer is one of those , "It all depends" on what you want for
reliability. It also depends on whether you will have any connections
underground. OTOH, connections underground are little different than
connections above ground. They should be treated the same.

Crushed rock and very rocky soil are about the worst location for
burying coax. PVC conduit is *cheap*, or at least relatively
inexpensive, particularly if you are only going to have one run of
coax. I have 7 coax cables 3 TV RG-6 cables, two rotor cables, a
power cable tot he 2-meter preamp and some other assorted *stuff* run
through mine. I use a 75 foot run of 4 inch PVC to a junction box on
the tower.. http://www.rogerhalstead.com/cablebox.htm

Go to the hardware and get a tube of silicon sealant and seal the
ends, if you don't think that's enough seal one end and shoot nitrogen
gas in the hose to displace the air and then seal it quickly.

A point or two here...If you want to force N2 through the coax you
need *both* ends open. However it *will* breathe as pressure changes
with temperature. Do NOT seal both ends of a coax run. Do the best
possible job up on top and leave the end in the house unsealed.
IF you seal both ends the pressure will eventually equalize. Then with
each temperature change it will either pressurize, or draw a vacuum.
This will eventually draw in moisture. I use heat shrink tubing on
top of the tower and fill the connectors with DC-4 silicon grease.
This works at least up through 440 and for all legal amateur power
levels.

SPLICES: The easiest and surest way to seal a splice from the weather
is to go to your local electrical supply house and purchase a length
of 3M (TM) 0800 IMCSN .80/.22 20/5/6mm flooded heat shrink tube for
RG-8 size cables. The stuff is *about* $10 for a 40 inch length. It
is coated inside with something akin to hot melt glue. It not only
does a tremendous job of weatherproofing, but adds mechanical strength
as well. Don't be cheap and expect to reuse the connectors although
you might get lucky and be able to do so.

"Unshrunk" the tubing will easily fit *over* a PL250, or N connector.
That .8 indicates the inside diameter prior to shrinking. It will
shrink all the way to 0.22 inches. Make your splice using either a
male to female connection, or two males with a barrel connector in
between. Slip a length of the heat shrink tubing long enough cover
the entire splice and extend at least 1 1/2 to 2 inches beyond the
connectors onto the coax jacket.
When applying heat to shrink the tube onto the splice be sure and
start in the middle and work outward. IF you start on the ends it will
look like a snake that just swallowed a very big frog by the time you
get any where near the center:-))
This method does a far neater and better job than coax seal and tape.
Less mess, adds strength, and is as waterproof as you are going to
get. It has the drawback of requiring a heat gun to shrink the tubing
(which sometimes means a very long extension cord, but I use them on
top of a 97 foot tower), nor will it fill a hole where coax passes
through like coax seal.

Roger Halstead (K8RI EN73 & ARRL Life Member)
www.rogerhalstead.com
N833R World's oldest Debonair? (S# CD-2)

Have a good day:')
.
Don't buy goods made in France or Germany and vacation somewhere else!

Hello....

Yikes what a big production. 15 years ago I had had two antennas
roughly 100ft away from the rig and I buried both coax cables with no
issues. One was Radio Shack/Tandy 8U the other was made by Carol
Cable Co (Again 8U).

The coax was average to low quality and it lasted with no change in
SWR or performance until the day I moved out 10 years later. It
probably is still there and would likely work! If you are still
worried go to Revy or Totem and purchase some platic PVC conduit and
run the cable through that. Stay away from goose greese or whatever
else they are suggesting you spread on your coax, what a mess it would
be......

Yuk...

Homac



Roger Halstead wrote in message . ..
On Sat, 18 Oct 2003 21:18:02 GMT, helmsman
wrote:

yea right wrote:

I would like to bury my coax for a distance of about 20ft. The location
consist of 6" of crushed decorative rocks over the top of very rocky soil.
SNIP
Anybody have any suggestions?

I can't find the original post, and going to Google to get it would be
starting another thread, soooo,,,, I'm just going to insert here.

The answer is one of those , "It all depends" on what you want for
reliability. It also depends on whether you will have any connections
underground. OTOH, connections underground are little different than
connections above ground. They should be treated the same.

Crushed rock and very rocky soil are about the worst location for
burying coax. PVC conduit is *cheap*, or at least relatively
inexpensive, particularly if you are only going to have one run of
coax. I have 7 coax cables 3 TV RG-6 cables, two rotor cables, a
power cable tot he 2-meter preamp and some other assorted *stuff* run
through mine. I use a 75 foot run of 4 inch PVC to a junction box on
the tower.. http://www.rogerhalstead.com/cablebox.htm

Go to the hardware and get a tube of silicon sealant and seal the
ends, if you don't think that's enough seal one end and shoot nitrogen
gas in the hose to displace the air and then seal it quickly.

A point or two here...If you want to force N2 through the coax you
need *both* ends open. However it *will* breathe as pressure changes
with temperature. Do NOT seal both ends of a coax run. Do the best
possible job up on top and leave the end in the house unsealed.
IF you seal both ends the pressure will eventually equalize. Then with
each temperature change it will either pressurize, or draw a vacuum.
This will eventually draw in moisture. I use heat shrink tubing on
top of the tower and fill the connectors with DC-4 silicon grease.
This works at least up through 440 and for all legal amateur power
levels.

SPLICES: The easiest and surest way to seal a splice from the weather
is to go to your local electrical supply house and purchase a length
of 3M (TM) 0800 IMCSN .80/.22 20/5/6mm flooded heat shrink tube for
RG-8 size cables. The stuff is *about* $10 for a 40 inch length. It
is coated inside with something akin to hot melt glue. It not only
does a tremendous job of weatherproofing, but adds mechanical strength
as well. Don't be cheap and expect to reuse the connectors although
you might get lucky and be able to do so.

"Unshrunk" the tubing will easily fit *over* a PL250, or N connector.
That .8 indicates the inside diameter prior to shrinking. It will
shrink all the way to 0.22 inches. Make your splice using either a
male to female connection, or two males with a barrel connector in
between. Slip a length of the heat shrink tubing long enough cover
the entire splice and extend at least 1 1/2 to 2 inches beyond the
connectors onto the coax jacket.
When applying heat to shrink the tube onto the splice be sure and
start in the middle and work outward. IF you start on the ends it will
look like a snake that just swallowed a very big frog by the time you
get any where near the center:-))
This method does a far neater and better job than coax seal and tape.
Less mess, adds strength, and is as waterproof as you are going to
get. It has the drawback of requiring a heat gun to shrink the tubing
(which sometimes means a very long extension cord, but I use them on
top of a 97 foot tower), nor will it fill a hole where coax passes
through like coax seal.

Roger Halstead (K8RI EN73 & ARRL Life Member)
www.rogerhalstead.com
N833R World's oldest Debonair? (S# CD-2)

Have a good day:')
.
Don't buy goods made in France or Germany and vacation somewhere else!

Thierry,
Please remove me from your 'art' list.
'Doc

On Sun, 19 Oct 2003 19:01:38 GMT, Roger Halstead
wrote:

On Sat, 18 Oct 2003 21:18:02 GMT, helmsman
wrote:

yea right wrote:

I would like to bury my coax for a distance of about 20ft. The location
consist of 6" of crushed decorative rocks over the top of very rocky soil.
BTW, in the case of sand, or clay with out stones, I just bury plain
old coax directly and have never had a problem doing that. Here that
just doesn't work. Particularly when the tower system usually gets
hit by lightening about 3 times a Summer.

Roger Halstead (K8RI EN73 & ARRL Life Member)
www.rogerhalstead.com
N833R World's oldest Debonair? (S# CD-2)

On Sat, 18 Oct 2003 20:39:15 GMT, yea right wrote:

First, after all this thread, this, the original post, turned up on my
server today Oct 21st, but dated the 18th.

I would like to bury my coax for a distance of about 20ft. The location
consist of 6" of crushed decorative rocks over the top of very rocky soil.

I intend to take the LMR-400 coax and push it through a garden hose to add
a layer of protection. However, I am worried that condensation will


Don't worry about it...LMR-400 hangs out in the rain, it'll survive
inside a garden hose full of water.

quickly fill the airspace of the hose with water and it will either
penetrate the coax outer jacket or interfere with the performance of it in
some unknown negative way.

Just don't have any unprotected connectors inside the hose. Probably
the best would be to drill a number of holes at 90 degrees to each
other along the length of the hose so it can drain. (before ins
talling the coax G)The hose only serves as a mechanical protector.


I can not flood the garden hose with petroleum oil as it will soon eat
through the PVC jacket of the coax or garden hose. Ideally, I would like

Don't worry about it. It's not worth the effort and eventually the
work to clean it up.

to flood the hose with the same stuff they put into underground cables. It
has a honey consistency and is not easily displaced by water. I was hoping
for some type of silicon oil but am unable to find anything similar at the
hardware store.

We used to use silicon oil, but you really shouldn't be worried about
it.

You might need to use some wire pulling soap (the gooey yellow stuff)
to push the LMR-400 through, but the stuff is stiff enough I would
expect it to go through fine.

It t takes a good can to two cans to get a cable through my 4 inch
conduit now that it has so many cables in it. The yellow stuff is
easy to clean up

Roger Halstead (K8RI EN73 & ARRL Life Member)
www.rogerhalstead.com
N833R World's oldest Debonair? (S# CD-2)

Anybody have any suggestions?

"Roger Halstead" wrote in message
...
On Sat, 18 Oct 2003 20:39:15 GMT, yea right wrote:
You might need to use some wire pulling soap (the gooey yellow stuff)
to push the LMR-400 through, but the stuff is stiff enough I would
expect it to go through fine.

It t takes a good can to two cans to get a cable through my 4 inch
conduit now that it has so many cables in it. The yellow stuff is
easy to clean up

Roger Halstead (K8RI EN73 & ARRL Life Member)
www.rogerhalstead.com
N833R World's oldest Debonair? (S# CD-2)

Roger,

If you are going to the trouble of using some kind of conduit, and assuming
it comes in 10 foot lengths, why not just push it through one piece at a
time? That is, push the coax through the pieces of pipe before you join the
pipes together. Besides, LMR400 is pretty stiff.

Tam/WB2TT

On Tue, 21 Oct 2003 21:14:06 -0400, "Tarmo Tammaru"
wrote:


"Roger Halstead" wrote in message
.. .
On Sat, 18 Oct 2003 20:39:15 GMT, yea right wrote:
You might need to use some wire pulling soap (the gooey yellow stuff)
to push the LMR-400 through, but the stuff is stiff enough I would
expect it to go through fine.

It t takes a good can to two cans to get a cable through my 4 inch
conduit now that it has so many cables in it. The yellow stuff is
easy to clean up

Roger Halstead (K8RI EN73 & ARRL Life Member)
www.rogerhalstead.com
N833R World's oldest Debonair? (S# CD-2)

Roger,

If you are going to the trouble of using some kind of conduit, and assuming
it comes in 10 foot lengths, why not just push it through one piece at a
time? That is, push the coax through the pieces of pipe before you join the
pipes together. Besides, LMR400 is pretty stiff.

In my case I have 75 feet horizontal with two 45 bends at each end and
a 3 foot rise at the tower and 86 feet horizontal into the basement.
Getting more into that takes lots of soap and one hefty snake and it
still gets hung up at times.

http://www.rogerhalstead.com/cablebox.htm
There are (I'd have to go count to be sure now), 7 runs of LMR 400, 2
runs of RG-6 for the UHF TV antennas, One does everything cable to the
C/Ku band dish with rotor and polarization, two 3/8ths inch rotor
cable with one used for the rotor and the other for the remote antenna
switch.

With a single run of LMR 400 in 3/4 inch, I think pushing it through
one at a time would work fine. Although for no more than 20 or 30
feet...probably twice that you could easily push one run through the
full length. I'd guess you could push it through far longer runs than
that.

Roger Halstead (K8RI EN73 & ARRL Life Member)
www.rogerhalstead.com
N833R World's oldest Debonair? (S# CD-2)
Tam/WB2TT

Roger, just what is that white loamy stuff around the base of your tower
aside from ALL the coax? You need to show us a photo of the tower and
what you have hanging on it. It that sand that has blown up, opps, that
not sand. Your call tells me your in the northeast. So it must be
snnnnnow. I got COLD just looking at it. Have a nice warm day.
Marylou, N"5"XXX.

Roger Halstead wrote:

On Tue, 21 Oct 2003 21:14:06 -0400, "Tarmo Tammaru"
wrote:


"Roger Halstead" wrote in message
.. .
On Sat, 18 Oct 2003 20:39:15 GMT, yea right wrote:
You might need to use some wire pulling soap (the gooey yellow stuff)
to push the LMR-400 through, but the stuff is stiff enough I would
expect it to go through fine.

It t takes a good can to two cans to get a cable through my 4 inch
conduit now that it has so many cables in it. The yellow stuff is
easy to clean up

Roger Halstead (K8RI EN73 & ARRL Life Member)
www.rogerhalstead.com
N833R World's oldest Debonair? (S# CD-2)

Roger,

If you are going to the trouble of using some kind of conduit, and assuming
it comes in 10 foot lengths, why not just push it through one piece at a
time? That is, push the coax through the pieces of pipe before you join the
pipes together. Besides, LMR400 is pretty stiff.

In my case I have 75 feet horizontal with two 45 bends at each end and
a 3 foot rise at the tower and 86 feet horizontal into the basement.
Getting more into that takes lots of soap and one hefty snake and it
still gets hung up at times.

http://www.rogerhalstead.com/cablebox.htm
There are (I'd have to go count to be sure now), 7 runs of LMR 400, 2
runs of RG-6 for the UHF TV antennas, One does everything cable to the
C/Ku band dish with rotor and polarization, two 3/8ths inch rotor
cable with one used for the rotor and the other for the remote antenna
switch.

With a single run of LMR 400 in 3/4 inch, I think pushing it through
one at a time would work fine. Although for no more than 20 or 30
feet...probably twice that you could easily push one run through the
full length. I'd guess you could push it through far longer runs than
that.

Roger Halstead (K8RI EN73 & ARRL Life Member)
www.rogerhalstead.com
N833R World's oldest Debonair? (S# CD-2)
Tam/WB2TT

Remember that a right-angle bend is best served by 2, 45 degree bends
with a short straight section between them. This will make pulling
cable much easier. A "pull-box" at corners is a good idea as well but
environment-resistant (not "proof", that's not possible!) pull-boxes
aren't cheap or easy to find.

Russ, who is responsible for a lot of cable-pulling through conduit

On Wed, 22 Oct 2003 06:19:43 -0400, wrote:

Roger, just what is that white loamy stuff around the base of your tower
aside from ALL the coax? You need to show us a photo of the tower and
what you have hanging on it. It that sand that has blown up, opps, that
not sand. Your call tells me your in the northeast. So it must be
snnnnnow. I got COLD just looking at it. Have a nice warm day.
Marylou, N"5"XXX.

Roger Halstead wrote:

On Tue, 21 Oct 2003 21:14:06 -0400, "Tarmo Tammaru"
wrote:


"Roger Halstead" wrote in message
.. .
On Sat, 18 Oct 2003 20:39:15 GMT, yea right wrote:
You might need to use some wire pulling soap (the gooey yellow stuff)
to push the LMR-400 through, but the stuff is stiff enough I would
expect it to go through fine.

It t takes a good can to two cans to get a cable through my 4 inch
conduit now that it has so many cables in it. The yellow stuff is
easy to clean up

Roger Halstead (K8RI EN73 & ARRL Life Member)
www.rogerhalstead.com
N833R World's oldest Debonair? (S# CD-2)

Roger,

If you are going to the trouble of using some kind of conduit, and assuming
it comes in 10 foot lengths, why not just push it through one piece at a
time? That is, push the coax through the pieces of pipe before you join the
pipes together. Besides, LMR400 is pretty stiff.

In my case I have 75 feet horizontal with two 45 bends at each end and
a 3 foot rise at the tower and 86 feet horizontal into the basement.
Getting more into that takes lots of soap and one hefty snake and it
still gets hung up at times.

http://www.rogerhalstead.com/cablebox.htm
There are (I'd have to go count to be sure now), 7 runs of LMR 400, 2
runs of RG-6 for the UHF TV antennas, One does everything cable to the
C/Ku band dish with rotor and polarization, two 3/8ths inch rotor
cable with one used for the rotor and the other for the remote antenna
switch.

With a single run of LMR 400 in 3/4 inch, I think pushing it through
one at a time would work fine. Although for no more than 20 or 30
feet...probably twice that you could easily push one run through the
full length. I'd guess you could push it through far longer runs than
that.

Roger Halstead (K8RI EN73 & ARRL Life Member)
www.rogerhalstead.com
N833R World's oldest Debonair? (S# CD-2)
Tam/WB2TT