[TowerTalk] Cage dipole revisited.

[Andy]

> If it is truly a cage dipole then it has no gain over a regular dipole
> or 2.2 db gain over an isotropic source.

Only if you mount the cage dipole in free space!

Any dipole mounted somewhere above a good ground, could have some gain in
some directions ... compared to a dipole in free space ... and so it would
exhibit a positive dBd number.  And many do.  There is no snake oil in that.
Some of you folks are confusing any randomly mounted dipole with the ideal
dipole in free space.  The mounted dipole will not have 2.16 dBi or 0 dBd,
and except for losses, it WILL have gain over the ideal dipole.  (However,
the direction with the most gain might or might not be where you want it.)

The fact that it is a cage dipole, is not what gives it gain.  (Though it
would have slightly more gain than a real dipole constructed out of the same
wire but only one of them.  But that's not the same thing as dBd.)

Heck, a yagi is (has) a dipole.  But using that fact to claim that its gain
must be precisely 2.16 dBi is just plain hockeypuck.

Andy