Windom Antenna
The Carolina Version

Think of the "Carolina" windom antenna (the modern version of the windom) as an "upside down vertical antenna", hanging down from its counterpoise strung (more or less horizontally) some 10 meters (or more) above ground.

In other words, the 22 feet vertical component of the "Carolina" - between the 4:1 matching voltage transformer and the current choke balun - is a vertical antenna, fed at the tip.



This vertical does not require a ground or a system of radials!

Carolina Windom antenna.

How The
Carolina Windom
Works

Because the antenna is not fed at its center, the RF currents in each horizontal radiating section are very much unequal. This makes the vertical coaxial feedline radiate RF energy.

Normally, in the case of normal (balanced) dipoles, we try to avoid this from happening.

But, in this case we want the feedline to radiate!



Extra Radiation

By letting it do so, the outer shield of the 22 feet long vertical coax (RG-8X) radiates to fill in the gaps in the signal pattern radiated by the top portion of the antenna.

The 22 feet portion of the feedline effectively becomes an upside down vertical, located high above ground and free of ground losses normally associated with verticals based on the ground!

The "Carolina" windom thus becomes a near-omnidirectional antenna. This is a very desirable characteristic on the lower bands 40 meters, 80 meters and 160 meters.

The choke balun at the bottom of the 22 feet radiating vertical effectively isolates it from the coaxial feedline going down to the transceiver. This prevents RF from being fed back into the radio operation position. Another very desirable feature.

Choking Off The Excess

The choke balun at the bottom of the 22 feet radiating vertical effectively isolates it from the coaxial feedline going down to the transceiver. This prevents RF from being fed back into the radio operation position. Another very desirable feature.

Oustanding Performance

The users of this special version of a windom antenna have reported that the near-omnidirectional characteristic is most pronounced near and over salt water.

The "Carolina" windom is...

  • Very efficient because no RF energy is lost in a "lossy" ground system.
  • Very effective because a large portion of the RF energy is radiated, much of it at low angles, omnidirectionally.

These same characteristics also make the "Carolina" windom an excellent receiving antenna.

The Original
Windom Antenna
of The 1930's

The original windom was a Zepp-type antenna fed 14% off-center with a single wire.

The single-wire feeder radiated RF all the way into the operating position.

A very undesirable side-effect ... that the "Carolina" version not only eliminated but transformed into an extra asset by...

  1. choking off the RF, present on the coax, before it enters the shack,
  2. thus forcing the choked off RF to travel instead toward DX stations.


Take a look at my Carolina windom antenna!



73 de VE2DPE
Claude Jollet
7, Rue de la Rive, Notre-Dame-des-Prairies, Québec, Canada J6E 1M9

QTH Locator: FN36gb


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› Windom





Antennas

Section
Contents

Introduction

Selecting

The Classic Dipole

Wire Antennas

Space Saving Ant

Short Antennas

"Loaded" Dipole

10M Antenna

160M Antenna

160M Windom

Carolina Windom

Design Software

Homemade Ant

Antenas (!)

The Transmatch

Towers

Testimonials



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