Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: running coax underground  (Read 1008 times)
EI2GLB
Member

Posts: 491




Ignore
« on: April 21, 2008, 01:41:13 PM »

HI all

i am currently building my new qth and am at the stage of putting in the paths and garden area.

i want to run some 4" ducting under the lawn to where the tower will be (someday). and run it back into the house.

now no matter how i try to prevent it there will be mositure in the ducting should i drill holes on the underside to let it leak out or will that be asking for trouble.

i plan to fill in the bottom of the trench with some small pee gravel so it should help to remove all moisture and prevent any entering from below.

i want to use normal type 213 and w103 coax will this be good enuff hope to keep runs as short as possible but dont want it to near the house.

anyone have any tips or tricks for this

thanks
Trevor
Logged
KB9CRY
Member

Posts: 4284


WWW

Ignore
« Reply #1 on: April 21, 2008, 05:48:33 PM »

now no matter how i try to prevent it there will be mositure in the ducting

Correcto mundo, moisture will appear from condensation from the air in the duct and as the ground temperature fluctuates from day to night.


should i drill holes on the underside to let it leak out or will that be asking for trouble.

Yes for sure for sure.


i plan to fill in the bottom of the trench with some small pee gravel so it should help to remove all moisture and prevent any entering from below.

Perfect!

i want to use normal type 213 and w103 coax will this be good enuff hope to keep runs as short as possible but dont want it to near the house.

Negativo.  You really really want to purchase direct burial type of coax.  Regular will work, but will fail far earlier than the stuff made for burial.  It's all a matter of cost now versus future cost.
Logged
KB9CRY
Member

Posts: 4284


WWW

Ignore
« Reply #2 on: April 21, 2008, 05:49:18 PM »

Oh, I also wrap mine with landscape fabric to keep the mud out.
Logged
EI2GLB
Member

Posts: 491




Ignore
« Reply #3 on: April 21, 2008, 10:29:02 PM »

Thanks For the Reply can you clarfify a point for me

when i asked should i drill holes to let moisture out should i do this or not.

Thanks

Trevor
Logged
K9KJM
Member

Posts: 2416




Ignore
« Reply #4 on: April 21, 2008, 11:14:15 PM »

I use the corrugated drainage tube from farm supply stores (Available in 3 or 4 inch sizes, Either already punched with drainage slots or not) Sells for 20 some dollars per 100 foot roll.

With the corrugated tube, Any slight moisture will lay on the bottom of each corrugation, And the coax will lay on above it.

When you have the trench open, Be SURE to also lay in a nice heavy copper wire (Along with ground rods every 20 or so feet) OUTSIDE the conduit for bonding your ground systems together.

RG-213 coax should be fine for HF, But for VHF/UHF you need something much better. Times LMR-400 for a shorter run like 75 or so feet total, OR find some surplus heliax.
Logged
KB9CRY
Member

Posts: 4284


WWW

Ignore
« Reply #5 on: April 22, 2008, 12:59:34 AM »

hould i drill holes to let moisture out should i do this or not.


Yes drill the holes or slope the tube and drain the low end.  But yes, drill the holes.
Logged
N1QOQ
Member

Posts: 188




Ignore
« Reply #6 on: April 22, 2008, 04:32:41 AM »

Better than drilling holes, pitch the conduit. This is the way we keep power conduits from filling with water.
Unless you use peastone and weed block roots and bugs can get in as well as any ground water. Depending on the length of the run you can pitch to the ends or the middle. Use a hand hole with 8" of stone under it. It will give you access as well as a sump for water to drain. A 12x24 handhole only cost about $40 and looks professional when done. 73 Paul
Logged
WW5AA
Member

Posts: 2088




Ignore
« Reply #7 on: April 22, 2008, 09:34:46 AM »

I ran my 213 through a rubber garden hose buried about 6" down. That was ten years ago! But then I'm a sucker for cheap and easy.

73 de Lindy
Logged
DH5AK
Member

Posts: 12




Ignore
« Reply #8 on: June 25, 2008, 12:48:04 PM »

you may take a closer look into the "Wirebook" edited by The Wireman. There you can find many recommendations concerning this topic.
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!