Years ago, ham radio operators more often than not had land, and usually there weren’t any restrictions on what kind of antenna they could erect on that land. These days you are more likely to live with less or no land, and even if you do own property, you might have restrictions that prevent you from putting up any kind of visible antenna.
But even if that’s not the case, you might not have room for an old-fashioned “tri-bander” or “cubical quad” that the hams of old preferred. [Waters & Stanton] has a 65-year-old design for a miniature beam that he explains, and it produces a good beam antenna in a reduced amount of space. You can watch a video about the antenna below.
The design uses a doublet — a dipole fed with a balanced line and tuned at the feed point. A 22-foot doublet can cover 20 meters down to 10 meters without traps. Adding a director and reflector element provides directionality and gain. A unique arrangement allowed a 12-foot boom to support multiple elements on some bands by introducing a central coil on some elements. For example, the director is tuned to 15 meters using a center coil. But the coil is shorted with a 10 meter quarter stub that acts as a short on that band. You can see a complete explanation in the video.
We were hoping to see a build and some on-the-air testing, but, apparently, that is left as an exercise for the viewer. We imagine that 65 years ago, you’d use a grid dip oscillator to tune the stubs. Today, an antenna analyzer would do the job easily.
The center coil allows for easy multiband operation via the shorting stub, but elements with center coils radiate less effectively than elements with coils further out from the center. Then again, coils have the most shortening effect where the current is greatest, and that’s at the center of a half wave dipole.
A worthwhile design for those who try to make use of whatever little real estate available.
Even if the gain isn’t up to the gain of a full size, the mini beam benefits your receive situation by reducing same-frequency interference from undesired directions, also by not wasting transit power in unintended directions.
Smaller beams, exhibit less wind-loading, and less stress on the rotator. With increased storm intensities lately, something to keep in mind.
You can’t beat a covert 9’x9′ horizontal tx/rx loop in you 2nd story attic with a tuned vertical rx/tx loop on a rotator in the center. Some phase wizardry let’s you point the combined tx antennas and null rx qrm on the vertical loop. It also works great on NVIS.
Got a link to an article please?
This 2nd loop on a rotator sounds intriguing.
Thanks either way :-)
I have heard of some Home Owners Associations (HOAs) will stop people putting up 6″ antennas.
The modern day manifestation of the old adage that absolute power corrupts absolutely.