There was a note in QST some years ago pointing out that
standing antennas UP to check SWR before installing would
give better results if the reflector is ABOVE ground. The
Lower the F/B, the HIGHER it needs to be to prevent detuning
effects from the ground. Unfortunately, I don't remember
the recommended heights for high and low F/B. I believe they
were in the range of a few few feet to maybe 10 ft or so for
high band antennas.
Tom N4KG
On Wed, 06 Nov 2002 Tom Martin <tmartin@chartermi.net> writes:
> I should have mentioned that it is a two element wire beam using
> bamboo to support the 12 gauge stranded wire. I will tilt it and
measure
> again. I am feeding directly with RG 213 with a .20 spacing.
>
> Tom W8JWN
>
> Tom Martin wrote:
>
> > I built a 15 meter beam with the DE cut for 21.250. The MFJ
> analyzer
> > reads 23.000 for a 1-1 match. I added about 8 inches and the best
> SWR
> > is at 22.500. These tests were made at 10 feet. Will the
> frequency go
> > down when the beam is at 40 feet? I can't believe that I have to
> keep
> > adding to the DE.
> >
> > Tom W8JWN
> >
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> _______________________________________________
> AN Wireless Self Supporting Towers at discounted prices,
> See http://www.mscomputer.com
>
> Wireless Weather Stations now $349.95. Call Toll Free,
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