I'd like to know what you guys using a shunt fed
tower on 160 are seeing for the 1.5:1 bandwidth. After much work over the
summer trying to improve things on mine I have wound up with a 1.5:1
bandwidth of 70 KCs with the center of this being at 1.1:1. I'd like to
compare with what the rest of you have. The work I performed on mine this
past summer included raising the feedpoint to the same level as the 30
elevated radials at about 8 feet high vs. being at ground level 8 feet
below the radials, extending the shunt wire out to 18 inches away from the
tower vs.15 inches before, and replacing connecting cables to with big
gauge welding cables.
After all else failed I was finally able to get a
1.1:1 SWR at 1820 by pulling in the shunt wire in to about 6 inches away
from the tower at about the half way point of the length up the tower. This
is the same level where I have a 10m monoband yagi mounted that I could not
rotate to the end stop because of the shunt wire. I can now rotate that
yagi without it touching the shunt wire and it allowed me to achieve the
best match I have had to date on the 160m antenna. The shunt wire and tower
now resemble the letter K. The first DX QSO this season occurred early this
week with a PY2 who was 10db over S9 on 1850 SSB! Hope this turns out to be
a good winter DX season!
Please reply directly to me with your comments on your 1.5:1 bandwidth.
Thanks in advance.
73 Ken N4UK EM84xp
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