RadioBanter - View Single Post - DOUBLE RESONANCE IN DIPOLE...THE CAUSE?????

November 10th 04, 07:42 PM

(Fractenna) wrote in message ...

There is no problem. Dipoles and other antennas always show multiple
resonances. Just take an SWR analyzer and sweep a wide frequency range.
You'll find resonances all over the place.

Bill W6WRT

A properly tuned and positioned dipole will
be resonant at only one frequency. Double-dips
are a bad sign, and the return loss suffers.

Dipoles are essentially harmonic devices, so they experience harmonic
resonances.

If you find resonances that are not harmonic on a dipole, then there are
loading objects that are producing them.

What exactly is your dipole? What is in proximity to it? How do you know that
the coax is choked properly?

Garden variety dipole.

But you have hit on one of the factors, i believe, which
is that initially, i was only about 4 feet off the ground.
Supposedly, dipoles need to be significantly over a 1/4 wavelength
above the ground. The second time, i had it at 6.5 feet or so.

I didn't need a choke with this one.

I'm using an MFJ-259.

What do you think was the other factor?

Slick