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Richard Clark · September 27th 10, 03:25 AM posted to rec.radio.amateur.antenna

On Sun, 26 Sep 2010 18:24:39 -0700 (PDT), wrote:

On Sep 24, 7:38*pm, WING wrote:
I am wondering if anyone has used an elevated screwdriver and elevated
radials? I wish to put this up at 22 ft. Above the garden. With at least
1/10 wave radials at 40 meters. Any suggestions?

Wing

--
WING

The radials need to be tuned when elevated. If you used 1/10 wave
radials, they would have to be loaded to be 1/4 wave electrically,
and I wouldn't expect the performance to be near as good as full
length 1/4 wave radials. And.. the radials need to be tuned for
each frequency you operate. Which usually means multiple
elevated radials for each band to be used.
Myself, I would try to use a longer radiator as well, but a
screwdriver will work.. A longer radiator would work better.
I had a full size 1/4 ground plane up for a good while.
32 ft radiator with four 32 ft radials. The base of the radiator
was at 36 ft, and the radials sloped down at about a 45 degree
angle. I built the radiator from an old 5/8 CB antenna that I
reinforced with inner tubing and lengthened to 32 ft. It was
totally self supporting and require no radials. Pretty light too.
I don't have it up now, but I still have the antenna on the side
of the house.
To avoid radials of any real length the best bet is usually to go
with some type of loaded half wave design. IE: Cushcraft R5,
etc..

Hi Mark,

Of late it seems most questions are of the "drive-by" category with no
apparent interest by the OP for responses.

However, I know full well you will engage in dialog - so here goes:

There is no particular virtue in having the radials being resonant on
any band of operation IF the entire antenna is being tuned. And such
it would be with an elevated screwdriver.

It then becomes something of an academic issue: why not discard the
radials and simply think of the elevated Screwdriver operating as a
vertical dipole with one end grounded (where the coax rises from below
where the shield is attached to suitable ground treatment)? Just sit
on the tune button until the ad-hoc VSWR match is found. That's how
Screwdrivers are tuned anyway, aren't they?

73's
Richard Clark, KB7QHC