[TowerTalk] What kind of antenna is this?

[Kevin Zembower]

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