[TowerTalk] Coaxial Moxon

[Dan Zimmerman N3OX]

>
> A quarter wave coax, shorted at the end shows an infinite impedance.Is it
> possible what is described in the link?


A coax just a little bit shorter than a quarter wave shows a VERY quickly
changing inductive reactance ... so you can change the stub length +/- a few
centimeters and find the exact value of reactance you need to load the
antenna.

But, it's VERY lossy to operate a stub near resonance as a reactance.  I
estimated something like Q = 1 or Q= 5 for the "quarter wave" (actually a
little shorter) stubs in that antenna, and a model of it seemed to suggest
that the gain would be *negative 10dBi* and it would have zero F/B ratio.

You might look at http://www.karinya.net/g3txq/coax_antennas/ as well.

73,
Dan