Friday, February 15, 2019

The Bi-Square

Another rarely heard antenna on the air is the bi-square. Probably due to its size. And many prefer coaxial cable to the 300 ohm ribbon feedline that the bi-square normally uses.

If you think a single element quad loop (1 wavelength perimeter) is large, double its size to get an idea of the bi-square's dimensions.  But despite what it looks like from afar, the bi-square is not quite a real loop since it is split at the top.

Still, if you have one tall tower (at least 3/4 wavelength high) the bi-square may be worth considering. It's basically a bidirectional gain antenna. If you've already got the wire the construction cost is low. And you may be able to use some ingenious remote switching with relays to change the antenna into a large loop for other bands. 

Bi-square ideas and discussion here:

The bi-square array reappears N4LBJ's 18 MHz version
Bi-square radiation How they work via HA5CFJ (Hungarian)
Curtain antennas W8JI explains how the bi-square is related to the Lazy H
Bi-square for 2 metres Manageable dimensions up here. By KG4ZNC
28 MHz bi-square used portable My one and only bi-square test (video)

PS: Into low power amateur radio? Covering equipment, antennas, operating and strategy, Minimum QRP is the book for you. Available in both ebook and paperback (some countries).

No comments:

Post a Comment

Upgraded website

Enjoy reading about diverse facets of amateur radio? Like building projects? Sometimes find my videos hard to find? If any of these applies ...