[TowerTalk] Buried HF/VHF feedlines

[Steve Maki]

Gotta push back on the conclusion here. I would replace the "splices 
should never, ever, ever, ever, ever be placed below grade or in a 
flooded conduit" with something like "should never be placed in a 
conduit and under ordinary circumstances should not be placed below grade".

A waterproof splice is EASY, but it results in a big bulge in the cable, 
which not only makes THAT cable hard to pull in and have confidence that 
you have not damaged the splice, but any others that you might want to 
pull in at a later date would be problematic.

Not only that but by the time you buy the extra connectors and spend the 
extra time doing a proper weatherproofing job, why not just beg borrow 
or steal a long enough cable to begin with.

But it's certainly possible using a number of different methods to make 
a coax splice that will survive UNDER water indefinitely. The legacy 
cellular industry MOP using a big glob of hand molded butyl rubber with 
multiple layers of stretched vinyl over the top with each layer 
extending further and further past the butyl, will create an area that's 
more impenetrable than any other place along the cable. You can take 
that to the bank.

-Steve K8LX

On 07/25/20 19:55 PM, Kevin Kidd wrote:

> Splices are "weather proof" not water proof and should never, ever, ever,
> ever, never be placed below grade or in a flooded conduit.  They will too
> often leak hanging on a tower, they will always leak underground /
> underwater.
> 
> I have pictures of 3in Air Heliax compressed to about half that diameter
> after freezing in a shallow, water filled, steel conduit in a MN swamp.
> 
> Hardline is waterproof and direct burial as long as it hasn't been spliced
> or damaged.  Bury the coax or conduit below the local frost line and don't
> splice it and you will be good for years.