I recommend a REFLECTOR array for better gain-bandwidth.
Last year I installed a wire 2L 40 reflector array inverted vee
style at our field day site (K4BFT). For the first time ever,
we beat the 20M station and W1 / VE's were calling us
which is quite rare. The reflector was 70 ft and the elements
were pulled out 100 ft to each side. The boom was a 1/4 inch
rope pulled over two 50 ft high baseball field light fixtures
after shooting a fishing line over them with a sling shot.
Element spacing was 20 ft. The beam was aimed North
(from ALA) and for the west coast, we use a vertically
polarized Delta Loop fed 1/4 WL down from the apex
which is supported at 50 ft and aimed broadside to W6/7.
de Tom N4KG
On Fri, 09 Mar 2001 "Mark ." <n1lo@hotmail.com> writes:
> Hello All,
> I am planning an antenna for our club to use this summer for a
> special event
> station adjacent to a lighthouse on a sandy island in Chesapeake
> Bay.
>
> I acquired two very nice, 33' telecoping fiberglass masts made by
> DK9SQ in
> Germany and imported by Kanga US. See their web site at:
> http://www.bright.net/~kanga/kanga/
>
> These appear to be made specifically for holding up antennas. They
> have 10
> sections and collapse down to less than 48" long. They only weigh
> 2.2
> pounds.
>
> My plan is to support these on top of domestic, Channel-Master
> push-up poles
> (available at Lowe's home centers) for a total reach of about 60
> feet. This
> is nearly 1/2 wavelength on 40m.
>
> I want to make a 2 element, 40 meter inverted VEE wire beam. As a
> starting
> point, I was planning to make the driven element a resonant dipole
> on 40m,
> fed with lightweight twinlead. After finding the resonant length for
> the
> wire I'm using, I would make a director of the exact same wire,
> measuring 5%
> shorter than the driven element length, and place it 0.15
> wavelengths in
> front, in the desired direction (toward the US).
> I haven't modeled this, but thought some of you that are more
> experienced
> might offer some suggestions for fine tuning the design. I'm not
> looking for
> fully optimized design, of course, so please steer me in the right
> direction
> for an effective, 2 element wire beam.
>
> thanks,
>
> --...MARK_N1LO...--
> Gloucester, VA (W4HZL club effort)
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