Posted by
Craig Smith on
Dec 20, 2010; 12:47am
URL: http://elecraft.85.s1.nabble.com/Semi-OT-vertical-wire-antennas-tp5851823p5851847.html
Lew, I've had considerable experience here with a 43 ft wire vertical. The
bottom line is that your proposed layout will work, and will be
SIGNIFICANTLY better on 20, 30, 40 and 80 than your loop if your interest is
in working DX. I use a remote tuner at the base of mine (CG-3000), but the
internal K3 tuner will tune it on all bands 10-80 even without any balun.
Of course there would be feedline losses involved with the tuner in the
shack and the radiation angle from the vertical above 20 meters won't be
ideal for DX. To answer your specific questions:
1) The wire will be fine and in practical terms indistinguishable from
using tubing.
2) Don't do the zig-zags with the radials. Just use as many 30 ft
straight ones as you have the time/patience for. I recommend 32 minimum.
60 to 100 would be ideal. The DX Engineering radial plate is a great help
with this. I used black AWG 14 THNN from Home Depot, etc. If retained on
the top of the ground, they will be imbedded in the grass within a few
months. This setup will be near ideal on 20, 30 and 40 and will work
surprisingly well on 80 in spite of the shorter than ideal radials. To
understand the radial situation in greater detail, refer to Rudy Severn's
articles from last year in QEX.
3) If at all possible avoid running the wire on the trunk of the tree. You
will have losses, especially in the summer when the sap is in there. 5 to
10 ft. spacing should be MUCH better!
Have fun with your project!
73 Craig AC0DS
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