[Antennas] Butternut Vertical

2002年8月16日 22:47:28 -0500

I have a Butternut HF-9V (which replaced a HF-6V that got damaged by
getting caught in a tree in a Winter windstorm). Both were mounted on a
10' pole braced to an upright of my patio cover. Both are very nice
antennas, good for DX (although obviously not as good as a beam).
Butternut states that radials are required. They are correct. 
Originally, I had only the Butternut-designed 40-10 meter radials
attached; my 80-meter SWR curve was moderately broad but the lowest SWR
was about 3:1 at 3650. I added one (1) additional wire cut for 1/4 wave
on 80. The SWR curve sharpened noticeably with the 3:1 bandwidth of
about 100 KHz, but at resonance it was about 1.2:1!
I don't know just how it would perform with three 80-meter radials only.
If you are going to put it on top of a 30' push up pole, you will need
guying in any sort of wind. You might as well use metal (stainless,
copperweld, etc) guys cut to form radials and get optimum performance
from the antenna.
Incidentaly, I don't like the way Butternut attaches the 75-ohm coax
20-meter transformer line to the antenna; center conductor to the bottom
of the radiating section, braid to the base. KI made up an L-bracket
with an SO-239 on it and added a PL-259 to the coax. This eliminated a
lot of breakage from flexing.
Dave W9LYA
What wrought doG hath?