The ladder line has an electric field surrounding it. If this field
penetrate some lossy dielectric next to the line(like soil) you will get
losses. If
you do this in a big enough pipe, such as a 4" plastic pipe you have to make
sure the ladder line is centered in the pipe. You could also use (better) a
metal pipe of some good conductor such as copper or aluminum. You still should
make sure the line is centered in the pipe. I think (but am not absolute
sure) that you could put a ladder line with 1" separation in a 4" pipe with
good
result. Just make absolutely sure no water gets into the pipe (lossy).
I recommend you to, instead, use two baluns at each end of a coax cable and
put that cable under the road. You may need to put the coax in some sort of
pipe/conduit to make sure you still have a coax "at the end of the season".
Hans N2JFS
____________________________________
From: barry@mxg.com
To: towertalk@contesting.com
Sent: 11/21/2008 5:58:40 A.M. Eastern Standard Time
Subj: [TowerTalk] Ladder Line Underground
A question from my Best Man, F/K9ORP:
Can Ladder Line be run thru underground conduit under a road
to feed antennas on a tower across the road, with no impact?
By itself?
Would a mix of coax and ladder line also work?
Barry, W5GN
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
**************One site has it all. Your email accounts, your social networks,
and the things you love. Try the new AOL.com
today!(http://pr.atwola.com/promoclk/100000075x1212962939x1200825291/aol?redir=http://www.aol.com/?optin=new-dp
%26icid=aolcom40vanity%26ncid=emlcntaolcom00000001)
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|