Burying coaxial cable
Plubius
but have heard two ways to go about doing this.
One idea is to bury the pipe and drill drainage holes in it to allow
moisture an escape route. I contend that this will also allow moisture to
enter, though the detrimental effects on the coax would still be much less
than if it were subjected to sunlight and the other elements.
The other idea is to bury the solid pipe sans drainage holes and seal both
ends with goodly amounts of coaxial sealant so as to eliminate the intrusion
of moisture and various small insects.
I plan to use two 45 degree elbows on each end so as to not have a severe 90
degree bend to fish the cable through and to also allow abit of a down angle
for a rain drip loop.
As of now I am just looking for input from others who have done this, one
way or the other.
Thank you for your help.
N9PGE
Thomas C. Sefranek
Plubius wrote:
You can look at my repeater web pages where I did the very thing!
It has worked well so far! (4 years now...)
--
Thomas C. Sefranek WA1RHP
ARRL Instructor, Technical Specialist, VE Contact.
http://hamradio.cmcorp.com/41_Repeater/repeater.html
http://hamradio.cmcorp.com/inventory/Inventory.html
Plubius
Thomas C. Sefranek <t...@cmcorp.com> wrote in message
news:376C1D74...@cmcorp.com...
Robert Lay (W9DMK)
wrote:
>I would like a bit of input on burying coax in PVC pipe. I have not done so
>but have heard two ways to go about doing this.
>One idea is to bury the pipe and drill drainage holes in it to allow
>moisture an escape route. I contend that this will also allow moisture to
>enter, though the detrimental effects on the coax would still be much less
>than if it were subjected to sunlight and the other elements.
>The other idea is to bury the solid pipe sans drainage holes and seal both
>ends with goodly amounts of coaxial sealant so as to eliminate the intrusion
>of moisture and various small insects.
>I plan to use two 45 degree elbows on each end so as to not have a severe 90
>degree bend to fish the cable through and to also allow abit of a down angle
>for a rain drip loop.
>As of now I am just looking for input from others who have done this, one
>way or the other.
>Thank you for your help.
>N9PGE
I am using buried PVC (no drainage holes) with all joints properly
made using the bonding agent sold for that purpose in the plumbing
supply stores - so I have no seepage at all.
The ends of the 65 foot run here are 90 degree elbows up to about 1 ft
above grade. Then I put two 90 degree elbows together at the top of
that in order to do a 180 - that keeps the rain out.
A variant on this scheme allows an end of the run to terminate in only
one 90 degree elbow at the 1 ft above grade, and then make a straight
run though the wall of the house.
In my case, I do not do that because of a need to allow other cables
to enter the same wall conduit. Since the other end of the pipe comes
up under the floor of a barn, it does not need the 180 degree bend at
the top of the pipe.
I agree 100 % with the concerns about threading things past 90 degree
turns. It's a bitch. However, I think the answer would be to make each
90 degree bend more gradual by using 45 deg elbows and a foot or so of
straight pipe between them.
Here's a trick I use to simplify the snaking: I tie a trolley cord at
each end of the pipe to some piece of furniture. The total length of
the trolley cord is twice the length of the pipe run. It was installed
as I made the pipe and buried it and is a heavy duty braided cord.
I simply tie the end of a cable to the cord and pull the cord through
the pipe, and the cable is simply pulled along with it. Be sure to
cap off any sharp ends with something more rounded before pulling it
through. For example, I put a barrel connector into the end of a
PL-259 before pulling it. An even better solution would be to modify a
barrel connector to have an eyelet into which the trolley cord can be
tied.
73 de Bob, W9DMK, King George, VA
Change "nobody" to "w9dmk" for e-mail
http://www.qsl.net/w9dmk
http://www.fortunecity.com/meltingpot/albania/784
Dan Richardson
(W9DMK)) wrote:
[snip]
>
>I agree 100 % with the concerns about threading things past 90 degree
>turns. It's a bitch. However, I think the answer would be to make each
>90 degree bend more gradual by using 45 deg elbows and a foot or so of
>straight pipe between them.
[snip]
>73 de Bob, W9DMK, King George, VA
>Change "nobody" to "w9dmk" for e-mail
>http://www.qsl.net/w9dmk
>http://www.fortunecity.com/meltingpot/albania/784
Bob,
I suggest you consider using plastic electrical conduit filings for
your bends. You can purchase 90º bends which are a sweeping type bend
that are designed with pulling wires in mind.
73
Danny, K6MHE
Dan Richardson
Bob Lewis
a large radius.
Robert Lay (W9DMK) <nob...@crosslink.net> wrote in message
news:376cfeb9...@news.crosslink.net...
> I agree 100 % with the concerns about threading things past 90
degree
> turns. It's a bitch. However, I think the answer would be to make
each
> 90 degree bend more gradual by using 45 deg elbows and a foot or so
of
> straight pipe between them.
>
> Here's a trick I use to simplify the snaking: I tie a trolley cord
at
> each end of the pipe to some piece of furniture. The total length
of
> the trolley cord is twice the length of the pipe run. It was
installed
> as I made the pipe and buried it and is a heavy duty braided cord.
>
> I simply tie the end of a cable to the cord and pull the cord
through
> the pipe, and the cable is simply pulled along with it. Be sure to
> cap off any sharp ends with something more rounded before pulling
it
> through. For example, I put a barrel connector into the end of a
> PL-259 before pulling it. An even better solution would be to
modify a
> barrel connector to have an eyelet into which the trolley cord can
be
> tied.
>
m_pa...@my-deja.com
antenna through one condit. I'm thinking of using
1" electrical conduit. My run length is about
130' with one bend in the middle ~45 degrees.
Does anyone have an opinion if 1" will work, or do
I need to go to the next larger size. --Thanks
Sent via Deja.com http://www.deja.com/
Share what you know. Learn what you don't.
m_pa...@my-deja.com
underground from my house to the antenna. I was thinking that 1"
conduit would probably work. There is only one bend ~45 degrees halfway
down the run. Has anyone done this ? Will the 1" work or do I need to
go to the next larger size ?
In article <tgSa3.56$F%3.1064@client>,
JohnsonHE
>I need to put in 2 RG-8 coax from my house to the
>antenna through one condit. I'm thinking of using
>1" electrical conduit. My run length is about
>130' with one bend in the middle ~45 degrees.
>Does anyone have an opinion if 1"
Uea, Put it in 4 inch flexible drain pipe and include a continuous loop of rope
so you can add lines as needed. You'll be glad you did.
W4ZCB
Bob Lewis
won't drive the cost that much. It'll make your pull easier and permit
the addition of a few more cables if needed later on. Plastic flex drain
pipe is cheep but you run the risk of cable ends catching on the
corregations. I'd go for PVC from an electrical house.
Use swept 90 sections for turns except going into the house. Standard
45s should work for your 45 deg turn. On the side of the house you can
use an "LB" box which gives a 90 turn into the house but has a removable
cover to make the pull easier. At the tower, sticking out of the ground
use two regular 90 elbows with no glue on the pipe end. You can slide
them over to keep the water out after you make the pull.
You don't have to bury the PVC very deep. A couple of inches below the
surface should do it so long as you remember where it is and don't
permit anyone like telephone or cable people to dig across it.
m_pa...@my-deja.com wrote:
>
> I need to put in 2 RG-8 coax from my house to the
> antenna through one condit. I'm thinking of using
> 1" electrical conduit. My run length is about
> 130' with one bend in the middle ~45 degrees.
> Does anyone have an opinion if 1" will work, or do
> I need to go to the next larger size. --Thanks
Gary Coffman
>made using the bonding agent sold for that purpose in the plumbing
>supply stores - so I have no seepage at all.
But I bet you have water in the conduit anyway. It gets there by
condensation when the warm wet air enters the relatively cold
ground. Since there's no drain, it can't get back out. So the conduit
fills with water over a period of days or weeks during at least some
seasons of the year.
That's why you want to slope the conduit, and provide a dry well
into which the condensate can drain at the low end.
>I agree 100 % with the concerns about threading things past 90 degree
>turns. It's a bitch. However, I think the answer would be to make each
>90 degree bend more gradual by using 45 deg elbows and a foot or so of
>straight pipe between them.
Even better, use a PVC electrical conduit elbow. It has the sweeping turn
built in.
Gary
Gary Coffman KE4ZV | You make it |mail to ke...@bellsouth.net
534 Shannon Way | We break it |
Lawrenceville, GA | Guaranteed |
Gary Coffman
>I need to run 2 RG-8 size cables through an electrical conduit ~150 feet
>underground from my house to the antenna. I was thinking that 1"
>conduit would probably work. There is only one bend ~45 degrees halfway
>go to the next larger size ?
1 inch won't work. That's slightly smaller than the diameter of two RG8
cables. Use at least 2 inch, and preferably 3 or 4 inch. You'll probably
want to add more cables later, and it is easier to only dig once.
Gary V. Deutschmann, Sr.
Underground, a piece of good coax will last well over 25 years even 40
years is not uncommon. It's the part above ground that the UV gets to
that seems to deteriorate the fastest.
TTUL
Gary
Reg Edwards
cables have been used, without armouring, for 40 years or
more on the ocean bottoms. And salt water under great
pressure is very corrosive.
--
Reg.
m_pa...@my-deja.com
landscaping between the house and the antenna and I want to make sure
that the cables have some protection from a shovel.
In article <376f19c0...@news.primary.net>,
Gary V. Deutschmann, Sr.
>I want to protect it from physical damage. We will be doing some
>landscaping between the house and the antenna and I want to make sure
>that the cables have some protection from a shovel.
I can understand that!
All of my buried coax was placed in exact lines from the centerline of
what it goes to, to the ground stake associated with the transitrap
used on that run. So before we dig, we run two bright yellow strings
spaced about 4 inches apart between the ground peg and the antenna
mount/tower/pole/whatever.
Now, if you can keep the squirrels from dining on the cable, I'm all
ears!!!!!
TTUL
Gary
Alvin B. Carlson
shipping, its not much more than standard RG-8. So what you've already
got the RG-8, the conduit is going to cost more than 65 cents a foot.
What am I missing here? Sure the conduit provides more protection,
but people run UV 120 VAC cable underground all the time and just
use conduit to protect it as it enters and leaves the ground.
KB7VHI
In article <7kkdsd$vvu$1...@nnrp1.deja.com>, <m_pa...@my-deja.com> wrote:
>I need to run 2 RG-8 size cables through an electrical conduit ~150 feet
>underground from my house to the antenna. I was thinking that 1"
>conduit would probably work. There is only one bend ~45 degrees halfway
>down the run. Has anyone done this ? Will the 1" work or do I need to
>go to the next larger size ?
--
Internet: alv...@sequent.com // Sequent Computer Systems, Inc.
Alvin B. Carlson // 15450 SW Koll Parkway
503-578-5956 Fax: 503-578-5070 // Beaverton, Or. 97006-6063
TLN...@revealed.net
and sealing the ends with duct seal. Also if the cable is larger, or
you plan to use more than one, the farmers use a black plastic Pipe
which is sold coiled up, by the foot. This also would work. The 90
degree bends aren't too bad, just make the radius very long, in other
words, dont try to make a 90 degree "kink" make the turns gradual!
Terry WB0VQP
On Sun, 20 Jun 1999 18:01:07 GMT, nob...@crosslink.net (Robert Lay
(W9DMK)) wrote:
>On Sat, 19 Jun 1999 14:36:35 -0500, "Plubius" <non...@nowhere.com>
>wrote:
>
>>I would like a bit of input on burying coax in PVC pipe. I have not done so
>>but have heard two ways to go about doing this.
>>One idea is to bury the pipe and drill drainage holes in it to allow
>>moisture an escape route. I contend that this will also allow moisture to
>>enter, though the detrimental effects on the coax would still be much less
>>than if it were subjected to sunlight and the other elements.
>>The other idea is to bury the solid pipe sans drainage holes and seal both
>>ends with goodly amounts of coaxial sealant so as to eliminate the intrusion
>>of moisture and various small insects.
>>I plan to use two 45 degree elbows on each end so as to not have a severe 90
>>degree bend to fish the cable through and to also allow abit of a down angle
>>for a rain drip loop.
>>As of now I am just looking for input from others who have done this, one
>>way or the other.
>>Thank you for your help.
>>N9PGE
>
>I am using buried PVC (no drainage holes) with all joints properly
>made using the bonding agent sold for that purpose in the plumbing
>supply stores - so I have no seepage at all.
>
>The ends of the 65 foot run here are 90 degree elbows up to about 1 ft
>above grade. Then I put two 90 degree elbows together at the top of
>that in order to do a 180 - that keeps the rain out.
>
>A variant on this scheme allows an end of the run to terminate in only
>one 90 degree elbow at the 1 ft above grade, and then make a straight
>run though the wall of the house.
>
>In my case, I do not do that because of a need to allow other cables
>to enter the same wall conduit. Since the other end of the pipe comes
>up under the floor of a barn, it does not need the 180 degree bend at
>the top of the pipe.
>
>I agree 100 % with the concerns about threading things past 90 degree
>turns. It's a bitch. However, I think the answer would be to make each
>90 degree bend more gradual by using 45 deg elbows and a foot or so of
>straight pipe between them.
>
Rick Rikoski
<alv...@sequent.com> wrote:
> What am I missing here? Sure the conduit provides more protection,
> but people run UV 120 VAC cable underground all the time and just
> use conduit to protect it as it enters and leaves the ground.
Alvin, it depends on whether you have small rodents like "grinnies"
(chipmunks) or gophers in your yard. Once they bite thru, electrolysis
sets in and the coax dies.
I buried a bundle of 6 coaxes in a 125 foot run, 11 years ago and I am
down to one usable coax.
Jim Rodenkirch
diameter and times that number by two), double the result at a minimum.
I ran PVC from the shack out to my antenna (planned one coax run and
four wires for control/whatever); even thought I'd measure it all and
applied the 25% factor, I wish I'd selected a 1/2 inch larger
pipe...never hurts to have lots of room as pulling and stuffing cable
through a pipe that's "big enough" is always difficult...kinda a
Murphy's law kind thing..
Jim R. K9JWV
m_pa...@my-deja.com wrote:
> I need to put in 2 RG-8 coax from my house to the
> antenna through one condit. I'm thinking of using
> 1" electrical conduit. My run length is about
> 130' with one bend in the middle ~45 degrees.
> Does anyone have an opinion if 1" will work, or do
> I need to go to the next larger size. --Thanks
Jim Rodenkirch
diameter and times that number by two), double the result at a minimum.
I ran PVC from the shack out to my antenna (planned one coax run and
applied the 25% factor, I wish I'd selected a 1/2 inch larger
pipe...never hurts to have lots of room as pulling and stuffing cable
through a pipe that's "big enough" is always difficult...kinda a
Jim Rodenkirch
diameter and times that number by two), double the result at a minimum.
I ran PVC from the shack out to my antenna (planned one coax run and
four wires for control/whatever); even though I'd measure it all and
applied the 25% factor, I wish I'd selected a 1/2 inch larger
pipe...never hurts to have lots of room as pulling and stuffing cable
through a pipe that's "big enough" is always difficult...kinda a
Barry
You will probably want to add another coax, maybe a rotor control
cable or two at a later date. I suggest 3 inch minimum. I have a 4
inch PVC buried, and it's getting to the point where I wish I had a
second one (and that doesn't include the 2 hardline runs buried
outside the PVC.
BTW, go to your electircian's outlet and pick up a bottle of cable
pulling soap. It makes all the dfifference in the world
73 Barry W2UP
>
>m_pa...@my-deja.com wrote:
>
>> I need to put in 2 RG-8 coax from my house to the
>> antenna through one condit. I'm thinking of using
>> 1" electrical conduit. My run length is about
>> 130' with one bend in the middle ~45 degrees.
>> Does anyone have an opinion if 1" will work, or do
>> I need to go to the next larger size. --Thanks
>>
>> Sent via Deja.com http://www.deja.com/
>> Share what you know. Learn what you don't.
>
--
Note - Remove the X from my e-mail address for direct replies
John Gilbert
Why not just buy coax designed to be direct buried? I see LMR-400DB and
DB2040 are both low-loss 50 Ohm 1/2" braided cables that are filled with an
inert polymeric flooding compound that prevents that water from entering.
--
John Gilbert
jo...@comm.mot.com
J
would amount to a 180 degree, downward pointing end in which the coax
would enter. Depending on the size of coax to be utilized, it is
sometimes easier to install the 180 degree portion and feed it up the
coax to a point that would leave a sufficient amount to pull into the
house. Once the house end is secured and tested, you can pvc the 180
degree portion to the upright portion and seal the end. This will
provide the required rain loop and does nothing noticeable to the SWR on
the cable.
--
J Edgar/NS5N & Maureen/KE4GSZ send>>>
Reg Edwards
planet take a fancy to coax. It has no food value
whatsoever. There are wierd creatures thousands of feet
below the waves, nibbling away at phone cables lying on the
ocean bottoms.
Could this be why international phone companies are
shifting to satellites ?
---
Reg
=================================
Bryan King wrote
> In the past I've left portions of
> RG-8 above ground and it either gets broken down by the
sun or chewed on by
> mice.
Peter O. Brackett
Now that you mention it, that is remarkable! But. . . I never thought of
it that way until you mentioned it. In my youth I spent 5 years at sea in
the Navy as an electrician's mate. Several times we found that shipboard
rats had chewed all the way through the insulation on electrical cables.
Even on the so called "ring main" power supply. This probably gives away my
age, these were/are old fashioned DC systems.] Once we found a rat that had
chewed all the way through the lead armour and insulation on the ring main,
electrocuting itself, causing a short circuit and shutting down a part of
the ring.
Is there some unknown food value in electrical insulation that attracts
creatures, or is it simply hunger and curiosity that attracts animals to
cables?
Anyone know?
BTW . . . Re: burying coax: In some of my previous QTH's, when forced
into burying coax, I have discovered that it is always important to make
sure that the system is "well balanced" since "antenna" currents flowing on
the outside of the coaxial outer conductor will simply heat up the earth
rather than acting as incidental radiation. [i.e. antenna currents must be
kept off the outside of the outside conductor with choke baluns, or whatever
since they cannot radiate from underground!] With coaxial fed antennas in
which there is such unbalance there will be always be feedline radiation
from these antenna currents, sometimes significant. In most ham
installations, this incidental feedline radiation simply causes a distortion
in the antenna pattern and the amateur never notices the feedline radiation.
When the whole feedline is "in the air", all of the power pushed onto the
feedline is still radiated into space and contributes to the communications
"fun" of the amateur station. However if part or all of the coax feedline
is buried and carrying significant antenna currents on the outside of the
coax, then the antenna currents on the feedline simply heat up the ground,
and don't contribute to communications "fun". I discovered this in a buried
coax feedline [Stealth antenna site, inverted "L" fed with buried coax,
antennas were forbidden!] situation where I had a remote station give me
accurate field strength reports as I inserted and removed a choke balun.
The choke balun made a big difference [Several S units!] in remote field
strength.
Peter AB4BC
Reg Edwards wrote in message <01bec96e$fd7f0c60$b7fdabc3@default>...
Jonesy
> Isn't it remarkable how the various life-forms on this
> planet take a fancy to coax. It has no food value
> whatsoever. There are wierd creatures thousands of feet
> below the waves, nibbling away at phone cables lying on the
> ocean bottoms.
That certainly raises a question or two that have always
bothered me:
What did those creatures eat in the millenniums prior to man's
'advancement' to the state where he could deliver such material
to the bottom of the sea?
-and-
Where did skunks go to die before man developed asphalt roads
and motor cars?
Inquiring minds....
Jonesy W3DHJ
--
Marvin L. Jones jonz<AT>rmi.net
Gunnison, Colorado
174 days to go until the Year 2000 -- So what!
540 days to go until the 3rd Millennium of the C.E.
Reg Edwards
starve to death with stomachs full of the stuff.
But it has the same texture and appearance of candles - parafin wax -
in even feels greasy to the touch. Candles are very edible. Didn't
esquimos eat them before McDonalds opened up in the Arctic?
Apparently hungry rodents cannot detect the difference.
Reg.
L.M.Preece
: There's no food value in polyethylene. Rats, mice and squirrels would
: starve to death with stomachs full of the stuff
I've had birds pecking at damn thick satellite downleads and got through to
the copper core. I found a good coating in grease annoys them a bit to the
point where they fly off and find something else to devour.
: But it has the same texture and appearance of candles - parafin wax -
: in even feels greasy to the touch. Candles are very edible. Didn't
: esquimos eat them before McDonalds opened up in the Arctic?
: Apparently hungry rodents cannot detect the difference.
Nor can my cats - hence a slightly high SWR on 70cms recently and a popped
diode or two !
(9 out of 10 cats prefer Whiskas - I could think up some radio pun but it
just wouldnt read well!)
Leigh....
--
+ + + + + Leigh Preece + + Keele University, Staffordshire, UK + + + + +
+ + Email - Internet: le...@media.keele.ac.uk + +