Hi Brian -
Good news that your coax has faired well underground, but I would
encourage everyone to carefully consider their plans before jumping in
without studying the full picture.
This is excellent testimony for the qualities of the tough and highly
impermeable polyethylene jacket of LMR400, other sizes of LMR solid
center conductor, and others such as DavisRF "Bury-Flex," and custom(not
mil spec) RG213's.
Your experience is not encouragement for the use of PVC and TPE jacketed
coax to be buried in the same manner, be they Class I OR IIA(NCV),
neither of which were ever designed for direct burial, in spite of what
even some of our ham journals have reported over the years. This would
include 9913 & 9913F, LMR400UF, mil spec RG213/U(8267), and, actually,
the vast majority of coax on the market that we use in our hobby.
If you mean LMR400UF when you say "LMR400(flex)," it has only been around
for a few years, so no point is proven - direct burial coax should last
20 years if properly installed and is not physically damaged. The TPE on
the 400UF isn't designed for more than 10 years of life ABOVE ground,
much less in it.
73,
Press Jones, N8UG, The Wireman, Inc., Landrum, SC, 29356
Sales (800)727-WIRE(9473) or orders@thewireman.com
Tech help (864)895-4195 or n8ug@thewireman.com
http://www.thewireman.com and the WIRELINE bargain page
Our 22nd year!
On Sat, 27 Feb 1999 00:03:42 +0000 alsopb <alsopb@gloryroad.net> writes:
>
>A data point for those who consider running coax underground
>
>I recently found the LMR400 (flex) coax I burried a number of years
>ago
>to run to my 160M inverted L. I should say the rototiller found it
>(along with some radials). The shield, braid, dielectric and center
>conductor look pristine. Frankly, I was suprised.
>
>The ground here is acid, clay with some moles.
>
>Only improvement I can suggest is to bury it deeper than 6".
>
>73 de Brian/K3KO
>
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