Tom Schiller, N6BT, has produced a lot of great designs using this
technique, and may have been the originator of it. His book is sort of
rambling and is in serious need of an editor, but the technical content
is excellent. Strongly recommended -- any ham who cares about antennas
should study it. Among other things, it debunks a lot of phony
advertising claimes, and provides excellent "BS filters" for use when
reading advertising claims and even product data sheets. Tom's work
produced the excellent Force12 antennnas. He may be the finest antenna
designer of his generation.
https://www.amazon.com/Array-Light-Third-Straight-antennas-ebook/dp/B07B8D6LJB
73, Jim K9YC
On 2/17/2020 9:51 PM, Dan Maguire wrote:
That's called a "Coupled-Resonator" dipole. For details on modeling
something like that see:
https://ac6la.com/aecollection4.html#15b
Dan, AC6LA
--------------------------------------------------------------------------------------
On Mon, 17 Feb 2020 14:41:19 -0500 Dave Sublette wrote:
I added a #14 THHN wire spaced 12" above my 40 meter rotary dipole. I cut
it to about 46 feet +/-. I modeled it on a program called Antenna Model.
With NO connection to the existing 40 meter dipole or its feedline, the
antenna is now a well matched antenna for both 30 and 40 meters. The
spacers were 1/2 inch fiberglass rods sawn from electric fence posts bought
at a local farm supply store. The stand offs were fastened to the dipole
element with short pieces of aluminum angle and U-bolts. I only used three
spacers for each half of the dipole.
This is the same technique pioneered by Force 12 antennas. It works.
73,Dave, K4TO
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|