I have been puzzled that cage dipoles have not been more widely used by radio amateurs over the years, because they provide important advantages; the most important generally being wider bandwidth. As you mentioned, a cage dipole has significantly greater bandwidth than a single-wire dipole, which tends to be especially important on lower bands that have widths that are relatively large percentages of center-frequencies. Cage dipole bandwidth can be made very wide if desired by simply using a large diameter cage.
Smaller wire size can be used, because several small wires in a cage emulate a single large-diameter radiator. Small wires are difficult to see from the ground, which can have stealth advantages where neighbors or spouses fail to appreciate the beauty of an antenna. (Unfortunately, cage spreaders are not so easy to make invisible.)
Cage dipole end-voltages are lower, which reduces the risk of corona in high-power applications.
A cage dipole is a balanced antenna that should be fed either with balanced line or via a balun, but of course, the same is true of a single-wire dipole.
I have used cage dipoles in a variety of applications with excellent results. I highly recommend them in applications where bandwidth is important.
Fan dipoles provide even greater bandwidths. It isn't difficult to construct a fan dipole that will have a VSWR less than 2:1 from 14 to 30 MHz, for example. I am equally puzzled that radio amateurs rarely use them either.
Last edited by admin
on 16 Nov 2006, 07:35, edited 1 time in total.