[TowerTalk] Ladder Line Underground

[Martin Ewing]

Quick answer is no.  The electric and magnetic fields on ladder line extend
out to several times the wire spacing.  (Out to infinity, actually, but
maybe 3 - 8 X for practical work.)  Anything inside that radius will affect
the impedance and/or loss of the line.  So, if you're willing to put it
centered in an 8 - 12" pipe (all by itself), it might work.  (Actually, it
becomes a kind of twinax if the pipe is conductive.)

You can use transformers (baluns) to convert from balanced line to coax and
back, but they want to work close to 1:1 SWR, and they have losses.

73 Martin AA6E

On Fri, Nov 21, 2008 at 5:58 AM, Barry Merrill <barry at mxg.com> wrote:

> 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
>
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-- 
Martin Ewing, AA6E
Branford, CT