putting coax in pvc under ground a good idea?

[darklyte24]

I want to run my discone antenna from a mast/tripod since my roof is spanish tiles and I rather not mount the antenna on the roof.

I have some LMR400, which i want to run in pvc and bury that then run the pvc or another material up to the roof where it would then run in the attic, then down a hole in the closet and to the radio.

second, should I do coax in or outside of the mast?


i drew a quick sketch of what i thought id like to do, im open to any suggestions
thanks for your help

 

[mass-man]

Not a good idea...the PVC will eventually leak, no matter what. Why does the mast need to be so far from the house? Move it closer, use less coax, have less loss! Attach the mast to the side of the house, in the hole and over to the closet.

 

[darklyte24]

i forgot to draw a few things.. ill delete the first drawing,

 

[davidgcet]

distance is a factor, but no reason to worry about water in the PVC. think about it, the coax is designed for outdoor use, where it is always exposed to water. so long as you don't knick the jacket when installing it, it will stay water proof for many years before the jacket finally breaks down. i've done it many times with everything from RG-58 to 1 1/4" hardline, never had an issue yet and some of them have been in place for 20+ years.

 

[GTR8000]

but no reason to worry about water in the PVC. think about it, the coax is designed for outdoor use, where it is always exposed to water. so long as you don't knick the jacket when installing it, it will stay water proof for many years before the jacket finally breaks down. i've done it many times with everything from RG-58 to 1 1/4" hardline, never had an issue yet and some of them have been in place for 20+ years.

Bad advice. The average coax outer jacket is not designed to be fully immersed in water, it's designed to be water resistant. Water and moisture will eventually make its way into the PVC, and will cause trouble down the road. You really want to be careful unless you're using direct burial coax, and even with that it's not foolproof.

Suggest reading this article, it has some pretty good advice on the topic.

Coaxial Coax Cable and moisture and burying

 

[davidgcet]

use LMR-400-DB then, it is watertight.

like i said, i personally have never had an issue with it using regular cable. though i have seen plenty of leaking connectors fill a cable up quickly!

 

[k9rzz]

I helped a friend put in a couple towers and I believe he laid down some sort of drainage tubing that he laid into a trench, then pulled cable through that.

 

[gewecke]

I want to run my discone antenna from a mast/tripod since my roof is spanish tiles and I rather not mount the antenna on the roof.

I have some LMR400, which i want to run in pvc and bury that then run the pvc or another material up to the roof where it would then run in the attic, then down a hole in the closet and to the radio.

second, should I do coax in or outside of the mast?


i drew a quick sketch of what i thought id like to do, im open to any suggestions
thanks for your help

Why not do it the easy way,just install a nylon support line from house to mast and secure your coaxial cable to that? The least amount of cable you use,the lower your signal loss.
n9zas

 

[DPD1]

I would use one of the cables made for underground, like BuryFlex... Then put that through some sort of tube/hose made for being buried. That's going to be better than PVC, because you won't have joints and it can flex with any ground movement or root issues. Then do everything humanly possible to seal both ends of the tube. But my first choice would be getting it on the house somehow.

 

[SCPD]

Why does the mast need to be so far from the house? Move it closer, use less coax, have less loss! Attach the mast to the side of the house, in the hole and over to the closet.

+1

It's a waste of time/effort and money. Don't you have a chimney or vent pipe to mount the mast?

If you must have it away from the house, then just use LMR-400-DB and bury it.

 

[kb2vxa]

Some people love doing things the hard way. KISS, keep it simple stupid. I've had some bad luck with chimneys and vent pipes so I'd just put it on wall brackets and run the coax in through the louvers on the side under the peak, short, sweet, simple, and the highest point of the house to boot.

Oh and BTW those "Spanish" tiles are actually Moorish since they were introduced during the Muslim conquest of the Iberian Peninsula. Now I wonder what they're called in Australia? (;->)

 

[KAM101]

Those are actually called Clay Roof Tiles, they been using them in Europe, Bahamas and The Caribbean for many many years, also very common in Florida.

 

[darklyte24]

Its a new house, no chimney

ill try to see what i can do, thanks for the input