Bob:

If I had to do what you are proposing, and could find no alternative, I would go purchase a bunch of the foam pipe
insulation, experimentally determine what spacing 6" chunks of it would still support the line adequately centered in
the pipe, and put that in 1-¼" or 1-½" pipe, whichever it fit the best. Bigger is better as someone else pointed out.
You might want to test some for RF loss, as the black version may well contain carbon. Styrofoam would be the best
choice, but I don't know of a cylindrical form of Polystyrene foam. Maybe 1" strips of it cut from 4' X 8' sheets of 1"
foam would work. Use your imagination, for gosh sakes. The PVC will survive underground satisfactorily, but paint the
exposed ends for longest life (or use short pieces of gray conduit for the exposed portion).

--
Crazy George
Remove N O and S P A M imbedded in return address


"Bob P" wrote in message news
For esthetic / XYL / neighboor reasons, I'm thinking of running balanced
"ladder" line to the back of my yard, via 1" PVC pipe with appropriate
measures to keep the water out, and burying it maybe a foot underground.
Length of the run might be 20 feet along the bottom of a deck and then 60
feet buried, give or take. Then straight up a tree centered between two
other trees to feed about a 80' center fed dipole.
Nothing else will be in the pipe with the feed line. Anyone have any
thoughts on why this might or might not work? The ground where it could be
buried, is on the moist side most of the year.
Bob
kb8tl