Topband: Best coax for direct burial?

[Jim Garland]

My forthcoming 160m vertical requires about a 700 ft run of coax. I'd like
to bury the coax over most of the run, but some of it will be elevated, with
high UV exposure. (I'm at 7000 ft elevation and sun shines 330 days/yr.) The
climate is very arid here (about 4-6 in rain/yr), so water ingress isn't a
major consideration. 

 

I'd like an RG-213 type coax with a solid dielectric, rather than an LMR-400
type, or anything with a foam dielectric. The losses aren't an issue, since
this will be used exclusively on topband and 80m. I'm unclear about what
"direct burial" coax means, especially with respect to the outer jacket. Is
polyethelene to be preferred over PVC with respect to toughness and UV
resistance?  Stranded center conductor is mildly preferred but not
essential. Mostly what I'm looking for is long-term reliability. I'd
appreciate advice and suggestions, and also any recommendations about
suppliers (some of whom give very little technical info about their products
and are rather cryptic about who actually makes the coax.)

Tnx and 73,

Jim W8ZR