[Antennas] RE: Strange Antenna ?????

[Harvey&Bessie]

That appears to be a cage antenna. The characteristic of a cage like that: broadbanding. 
Almost like that of the bi-conic dipole. You are right, there is very little information 
on that antenna in any of the amateur publications. It was popular among those who had 
frequency asignments space a little too far apart for a single dipole, who didn't want to 
put up dipoles for each or several frequencies. The antenna electrically "looks" like a 
very large diameter conductor. The broader banded we make such an antenna, the nearer the 
center (feed impedance comes to 377 ohms. thus, 300-ohm feeders work quite well without 
any additional matching.
Harvey/W4TG