On 5/23/22 12:13 PM, Kevin Zembower via TowerTalk wrote:
Well, I think we're heading in the right direction, but the one in the
Wikipedia picture just has two wires between the end spreaders, and the
one I saw had five. Also, the one in the picture seems to have something
in the middle of it, and the one I saw didn't.
Another thing, the antenna I saw seemed to be part of one of the
(multi-band) hex-beam antennas. It didn't have an obvious feed-point; it
just formed one of the hex sides of the (single band) hex-beam. The
other multi-band hex-beam band antennas didn't have this antenna attached.
Here's another illustration. It could have appeared in the legs labeled
1 or 2, or even could have been in the reflector legs, I guess, but that
seems improvable. Picture at
https://www.dropbox.com/s/1xk0rbc6a79g2zb/IMG_20220523_150816134.jpg?dl=0
-Kevin
You didn't show a feed point, so if it's "standalone" or "end fed" it
might be a way to make a synthetic "large diameter conductor" which
improves bandwidth.
The old style MF or LF antenna (like on the RKO logo) would have a top
hat that looked like this, fed either in the middle, or on one of the
towers. In which case the multiple conductors serve to increase the
capacitance and area of the "topload".
There are people making 3 wire T2FD's as well, as a sort of folded
dipole configuration, fed in the middle of the middle wire.
On 5/23/22 14:55, Al Kozakiewicz wrote:
https://en.wikipedia.org/wiki/T2FD_antenna ?
-----Original Message-----
From: TowerTalk <towertalk-bounces@contesting.com> On Behalf Of Kevin Zembower
via TowerTalk
Sent: Monday, May 23, 2022 2:54 PM
To: towertalk@contesting.com
Subject: [TowerTalk] Fwd: What kind of antenna is this?
There's a drawing at
https://www.dropbox.com/s/8omfop6trejx211/IMG_20220523_144427650_BURST000_COVER.jpg?dl=0
despite my very limited artistic talent.
-Kevin
KC3KZ
-------- Forwarded Message --------
Subject: What kind of antenna is this?
Date: Mon, 23 May 2022 12:22:01 -0400
From: Kevin Zembower <kevin@zembower.org>
To: towertalk@contesting.com
Hello, all,
At Hamvention, I saw a couple of antennas that seemed to be part of a
multi-band hex-beam. They consisted of two rings about 2 inches in diameter,
separated by about 3 feet, with 5 parallel wires between them.
On closer inspection, it seemed like a single wire double back and forth
between the rings. I've also seen a similar arrangement on Naval ships, albeit
much larger. They're mounted horizontally and seem to be fed from either end.
The literature on the sales table might have referred to this as a 'Short 40.'
The table was busy, and I didn't get to talk with the sales representative
about it.
Can anyone tell me the type or name of this antenna? Can it be modeled with
NEC? What are it's characteristics, advantages and disadvantages?
Thanks so much. Looking forward to learning more.
-Kevin
KC3KZ
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