Topband: Antenna Matching Question

[Rick Karlquist]

You can remote the tuning cap by using 1/2 wl of coax.
This will be something in excess of 150 feet, depending on
velocity factor.  The antenna won't know the 1/2 wave is there.

Rick N6Rk




Phil Clements wrote:
> 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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>