Topband: underground cables question

[Gert Meinen]

Hi John,

Never use PVC drain pipe to bury coax or other cable, the molecules are that
far apart that water eventually gets in no matter what.
Better to use the same pipe your water supplier uses to get the water to
your house, think its Polypropylene or something like that. That pipe will
not let water out or in, the water company hates to lose water. That's why
they don't use PVC which is a lot cheaper and mostly used for draining water
when that leaks through the material into the ground nobody knows or cares.

73 Gert, PA3AAV

-----Oorspronkelijk bericht-----
Van: Topband [mailto:topband-bounces at contesting.com] Namens John
Verzonden: donderdag 5 oktober 2017 8:11
Aan: topband at contesting.com
Onderwerp: Topband: underground cables question

Hi all, some  years ago I buried a 4 inch conduit about a foot deep in my
field , inside I run a control wire and a coax line RG213 to a 160 m
vertical the feeder was a total of 5/4 wavelength long about half of it in
the conduit, it was used as one line for a pair of verticals spaced 5/8 wave
apart. When first installed it worked very good but after a while I noticed
it dropped off and I suspected water ingress. An insulation test with 1000v
from my electricians test equipment showed indeed a fall in insulation
resistance.

So my question is I have a couple of large reels of commscope F1160 BEF
flooded 75 ohm
do you think I could put it in the same conduit which has allowed some water
in or would you make alternative arrangements . I realise it a direct bury
coax but appreciate advice.

I wish to get the two verticals going again will use 1 X 3/4 line above
ground 1x5/4 line part in conduit and a 1/2 wave to switch in and out above
ground.

regards


John Beaumont
G4EIM


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