Fred,
The shielded loop is implemented only as a small-size receiving antenna
(less than 1/10 wavelength diameter). The shielding has the sole function of
improving balance to ground and surrounding objects. A larger loop has a
different mode of radiation and does not not have the deep nulls that are
the main advantage of a small loop.
Thus, a full-size 1 wavelength loop will have no benefit from shielding, and
can simply be made with any appropriate antenna wire, as a typical Quad Loop
or Delta Loop.
73, Gary
K9AY
>I am planning to install a large loop antenna for 160/80/40 meters on my
> 155' Rohn 45G tower. I have been reading all the articles and information
> that I have seen. I plan on using ½ inch vinyl coated hardline rather
> than
> wire. I have read all I could find on electrostatically shielded loops.
> I
> seem to think that the hardline would work with its outer aluminum
> conductor
> being the shield and the inter-conductor copper wire as the loop. The
> shield would be open at the top of the tower. The loop would be close to
> a
> diamond shape in a vertical plane perpendicular to the earth. I would
> assume that the velocity factor of the hardline .81 would change the
> formula
> from 1005/f to 814/f. The hardline from the loop will intersect the tower
> at approximately 10 to 15 feet and would go straight down through a PVC
> tube
> into the basement of my Orchard Storage Building. At that point the coax
> shields would be bonded together to a bus bar that connects to the tower's
> grounding system and the inter conductors would connect to a Ten Tec 253
> antenna tuner.
>
>
>
> I would like to hear from anyone that has had any experience with the
> Electrostatically Shielded Loop Antenna. What do you think? Fred Mott,
> AB8AH
_______________________________________________
Antennaware mailing list
Antennaware@contesting.com
http://lists.contesting.com/mailman/listinfo/antennaware
|