[TowerTalk] Direct Burial?

[DavisRFinc@aol.com]

Larry, Ron, Steve:  Hi.  Both of these cables use a spec'd "weather resistant"
polyethylene (hereinafter "PE").  Based on my experience there are only three
grades of PE which are generally used for cable jacketing.  Each varies in
density and durometer, specific gravity, etc. however, all three are quite
adequate for direct burial.  PE is a higher density, plasticide free compound
as opposed to PVC of various compounds used often on cables.  Andrews points
out that the LDF40-50A, a .500" spec'd cable, is direct burial.   The
literature on Times LMR600, a slightly larger OD, does not point out burial
but it does refer to the aforementioned "weather resistant PE".  For all
practical purposes I am sure that it is as buriable as the Andrews PE.  When I
designed "BURY-FLEX" Tm I used a medium density, Union Carbide, PE.  Bottom
line, I would have no problem recommending or selling either the Times or the
Andrews, but I would certainly be biased toward "BURY-FLEX" Tm for a number of
reasons.  In order to choose the most advantageous, several other factors such
as attenuation, bend radius and cost are the obvious.  Another consideration
for direct burial is the likelihodd, if any, of the burial route being subject
to future heavy equipment excavation.   If so, the most appropriate route is a
"flooded" cable within a conduit.  Attenuation tends to be an issue with these
cables at UHF and above vs. Times, LMR or BURY-FLEX being better choices.   We
handle all three lines, as does THE WIREMAN and we have numerous dealers who
handle BURY-FLEX Tm.  I hope that this has been of some help.  73, Steve
Davis,  K1PEK, DAVIS RF Co., Commercial wire/cable, RF connectors, custom
cable design. Discounts to hams..........BURY-FLEX ™ low loss HF-microwave
HDPE coax; ....FLEX-WEAVE™ aerial wire. Registered trademarks of Davis
Associates, Inc. .  .LMR ™, Heliax™, PolyPhaser etc.  Visit our web site at
www.davisRF.com.  1-800-328-4773
"The Triad":   DAVIS RF Co., ORION WIRE CORP and The WIREMAN:	Three types of
expertise, three corporate buying power and customer inter-personal
relationships benefitting all.

<< In a message dated 98-05-30 19:49:35 EDT, lburke@wt.net writes:
  << Are either of the following considered "direct burial" cables?
    1. Andrew Heliax LDF4-50A
  2. Times LMR Coax LMR600>>
<    The distributor catalogs I have do not specifically say, leading me to
  believe they are NOT rated for that service. If that's the case, guess it's
  time to determine which will do more damage... direct burial or the
 lawnmower.    >
          <You're probably right. Direct burial cables will SAY direct burial
in
 their specs. Cheers,   Steve  K7LXC >


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