[BC] Direct Burial Transmission Line...

[Burt I. Weiner]

Not to long ago I had to replace all of the directly buried 
transmission and sample lines at a station.  I installed the new 
lines above ground, in conduit.  The manufacturer was surprised as 
the cable was all specified for direct burial.  It may be have been 
water proof but it certainly wasn't tooth-proof.  If you must go 
underground at least put it in good conduit that's tooth-proof.

Burt


At 07:44 PM 3/6/2007, you wrote:

>Usually, it is not run below grade. However, when it
>is done properly, it would have to be placed in something
>like a steam tunnel. Rigid typically comes in 20 ft.
>sections and a rigid run does require maintenance. Unless
>there are other things in the same run like steam, water,
>telephone, utility power etc., or overriding reasons, I
>would never consider putting rigid line underground in
>this day and age. Today we have air dielectic Heliax
>and that can go u/g safely in three different ways, all
>of which have been discussed on this list in the past,
>and mentioned in this thread to a limited extent.
>
>For an existing AM plant, directional boring is probably
>the best, taking the ground system into consideration.
>Where that is not a problem, such as a new build-out AM
>plant, or for a horizontal FM run, I'd be inclined to give
>the fiber duct that Mike mentioned first consideration.
>For a new plant, there is also always the old standby of a
>PVC liner inside clay or concrete pipe to consider, but
>I would never consider bare PVC. That is just asking for
>trouble, especially where the ground freezes during winter.
>
>---------------------------------------------
>Phil Alexander, CSRE, AMD
>Broadcast Engineering Services and Technology

Burt I. Weiner Associates
Broadcast Technical Services
Glendale, California  U.S.A.
biwa at earthlink.net
K6OQK