Michael Coslo wrote:
From time to time I lift my head, blink a few times, and utter some
banalities, so here we go.

The OCF topic got me to thinking, what is a Zepp?

I may even have the wrong terminoligy, I'm speaking of the antenna fed
with ladder or open line, and one end of the line is fed to the antenna,
and the other just sets up there, lonely and tied to nothing.

Is this the ultimate waaayyy off center dipole? I'm assuming the
feedline radiates a LOT.

- 73 de Mike N3LI -

Yep, you've got it right.

Here's a way to understand why the Zepp feedline *has* to radiate. If
the feedline didn't radiate, it would mean that the currents on the two
conductors were equal and opposite. At the antenna end, one conductor is
open so no current flows from it. If the currents were equal and
opposite, there would be no current flowing from the other conductor to
the antenna. And if the antenna had zero current, it wouldn't radiate.
So if the feedline didn't radiate, neither would the antenna.

In fact, the radiating and non-symmetrically placed feedline also
couples into the antenna, altering its current flow somewhat.

The Zepp antenna is so named because it was allegedly used in the form
of an end fed trailing wire on Zeppelin airships.

Roy Lewallen, W7EL