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Chattanooga Amateur Radio Club

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Dipole Antenna Stabilizer

 

Historically, my 80+ foot long dipole often gets “rolled” by high winds since it’s located above the treeline at our home (on a mountain ridge). This often requires a climb up one or both ends of the dipole (a 50 foot tower and a tall oak tree) to unroll or flip it back.

This must be done as a rolled dipole produces high SWR and can also act as a dead short (depending on the wire used in its construction). Both conditions are very bad on attached radios and at the very least, seriously affect transmission range.

Based on a best practice suggested by “Mr. Antenna” a.k.a. Phil Mullins W4PRE, I decided to apply the “pendulum principle” to help mitigate the rolling effect.

I purchased a one-pound, lead fishing weight and tied it with UV/Ozone-resistant Dacron antenna rope to center feed point of the antenna. It is tied in such a way as to spread the weight over two points.  The weight is about 4 feet below the lowest wire element of the dipole.  The arrangement adds “mass” but not wind load.  The pendulum or plumb bob effect slows the broadside sway of the antenna and mitigates the loading of wind gusts so the overall antenna is slower to react to wind events.

The setup doesn’t affect antenna tuning since the lead weight is small in size and electrically isolated from the dipole itself by the rope line. There are other variations of this configuration depending on your specific needs and antenna used.

Thanks Mr. Antenna!

Gary Ownsby AK4ZX