Vertical Antenna Anti-Gain

There was a humerous response in this discusson on the DX Engineering web site concerning the need for radials. The web page is here…

DX Engineering

It is in the pop-up link “how just a few radials can do wonders for your signal by WB2WIK/6.”

A commenter suggested the claim of an additional 20dB or so signal with the progressive additional of radials to the vertical too much to believe.

Most of the other commentors correctly suggest there was no gain just more signal in the desired DX low angles.

Antenna efficiency is also improved as the author shows us with the steady decrease of bandwidth as the ground resistive losses become less part of the total antenna feed impedance.

This is another good example showing why using a lot of ground mounted radials to get that ground resistance down will help you get the most of your ground mounted vertical.

Remember, if you measure your feedpoint impedance close to 36 ohms don’t worry about having an SWR over 1:1. The efficiency increase is probably worth it.

Leave a Reply

You must be logged in to post a comment.