[TowerTalk] Buried HF/VHF feedlines

[Jonathan - KE0YBL]

Hi All,
I feel like this has been done to death - and yet, the Internet has really been notoriously awful with misinformation for me the past few weeks. I appreciate your thoughts as I work through this!

I'm putting up a new tower primarily for HF and maybe some VHF. Given my ideal location is some ~350ft+ from the shack, I've been waffling back and forth as to whether to remote the radios in an enclosure, or bring Heliax back. I'm leaning toward the Heliax route.

I'm working with an experienced (decades) climber/tower company in my area (Minnesota), who has used 7/8" Heliax for $1.50/ft. This seems reasonable, and a fraction of new, thus making my project seem doable. Sadly may require an underground splice due to lengths, but one battle at a time. I'm open to other sources for such things.

Herein lies the rub -- my climber's experience has been (and probably yours as well) that directly burying this in our frozen tundra eventually results in crushed cable through thawing and freezing. I'm considering 3" or 4" HDPE conduit/innerduct to alleviate that, but given I'll need to go through a valley, condensate will condensate in the dip no matter what I do. I could perhaps drop the conduit down 36+" deep to avoid the frost level, but it'll still be sitting in water (albeit not frozen at that depth) without active moisture management in the run (fan, nitrogen (ugh), whatever - not feasible).

I feel like at this point I'm really overthinking it. Fiber to the tower and radios in a box would be much easier, but less desirable - but now I'm really torn.

I appreciate your feedback immensely,

Jonathan