[UK-CONTEST] Antenna Cables underground

[Chris Tran GM3WOJ]

Hi John et al

All cables here run underground from the indoor shack through 16m of grey 
drainage pipe - o.d.110mm - this is the minimum size I would recommend. 
Originally I had a 135-degree bend about 2m from the outside house wall, but 
this always caused problems until I replaced it with what the supplier 
called a 'long radius' bend - this was difficult to source and cost £24, but 
smoothed out the curve and made things a lot easier.

At its peak, I squeezed 2 x LDF5-50A, 2 x LDF4-50A, 3 x RG213, 3 x rotator 
cables + 1 x switching cable into this pipe, but that was a struggle. The 
pipe slopes slightly downhill, which makes keeping water out easy.

I would advise the following :
1.  Use the cheaper grey pipe/fittings - buried about 9" below the surface 
there are no strength issues (unless you want to park your car there, hi)
2.  Plan for possible future expansion of your antennas - use as wide a pipe 
as you can.
3.  Install extra/spare coax cables in the pipe
4.  The best method is to pull *all* the cables through at one time (with 
another rope attached to pull back the 'pull-through' rope) - ideally with 
heliax cables you can do this before fitting the connectors. A bunch of 
cables is much easier to work with than trying to add them one at a time - 
thin cables and the pull-through rope will get tangled as Roger mentioned.

73
Chris
GM3WOJ