Much has been written about matching 160 meter shortened vertical antennas,
but very little about 160 meter antennas that are too long. There were two
great articles in the old "Communications Quarterly" in 1998 about elevated
ground planes, but I have lost them over the years. My current system was
built from these articles.
The system here is a 195 foot Rohn 25 tower, with insulators at the 60 foot
level. The five sets of guy wires are all insulated from the tower, and
additional insulators along their length to be invisible to 160 meter RF.
The guys at the 60 foot level, just below the tower insulators are utilized
as the radials that form the ground plane. They are 110 electrical degrees
long. The system resonates at 1510 KHz, requiring a capacitor connected
across the feed point. 600 pf brings the system into resonance @ 1830 KHz.
There will soon come a day when I will not be able to climb to the 60 foot
level to adjust the matching capacitor when needed. The question is: Can I
place the capacitor at ground level, connected to the original feed point
via coax or open-wire line? Will this 60 foot line radiate? I do not want to
upset the radiation pattern of the system. I tried a motorized vacuum
variable several years ago, but it was a high maintenance item due to
exposure to the elements.
I am open to all suggestions; perhaps some brand new ideas will surface from
all the expertise on this reflector! After 57 years on the air, I am still
learning, and trying to make improvements here!
Thanks in advance for any/all comments.
(((73)))
Phil, K5PC
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UR RST IS ... ... ..9 QSB QSB - hw? BK
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