Topband: New Subject: 160M array feedline question

[Carl Braun]

Topbanders

Thanks to all who responded

I received a lot of good advice and will be taking it.  Specifically, the advice to bury the hardline rather than elevate it.

Some brought up the idea of my ground mounted radials becoming submerged in fresh water...however, that would only take place for a week or less during the spring here and, it would only happen if we had a slow snow pack melt and rain at the same time.  This happened here two years ago but only lasted for a week or so.

I am sure to have more questions as this project matures.  In the meantime, I will continue to work with my modified 80/160 Butternut vertical that's stuck in the snow.  It uses 4 pieces of 30' irrigation tubing for radials as well as some wayward wires to create the ground screen.  No amplifier. This winter I have 22 countries on 160 with it.  Looking forward to the array!

Thanks again

Carl W9LF

From: Carl Braun
Sent: Sunday, March 21, 2021 3:26 PM
To: topband at contesting.com
Subject: New Subject: 160M array feedline question


Hello Topbanders

I am currently awaiting the snow to melt here in the Northwoods of Wisconsin before starting the construction of my low band vertical array.  My verticals will be mounted in a low ground area near a lake and the area tends to get wet and sometimes floods in the early spring.  Water levels could reach 6" to 12" above ground.  My concerns relate to the hardline coaxial cable that will run from my lighting arrestor panel at the outside of my shack to the center of the two element vertical array which is 250' away.  I will be using 1 5/8" hardline that I was able to snag for a very good deal but am concerned about having the cable lying on the ground and possible become submerged should we get significant rain with the snow melt.

My plan is to elevate the feedline approximately 24" above the ground using old sections of Rohn 25 tower spaced every 10' or so.  Each vertically mounted 5' chunk of Rohn 25 will be buried 2' into the ground have a 3' 2x6 board laying horizontally across the tower that would act as a coaxial "shelf" that will keep the hardline out of the water and prevent any significant drooping between these Rohn support sections.

My question for the forum is related to the fact that I will have an elevated coaxial feedline with two ground mounted vertical antennas.  I plan to use an UNUN or similar line isolator/choke that would keep the hardline from becoming a extra radial.  Any thoughts from the forum on this set up? Any extra precautions I should take to keep return currents from flowing on the feedline?

Thanks in advance for any suggestions.

Carl W9LF