[TowerTalk] Truth, Fiction, or Fantasy?

[Jim Brown]

On 4/26/2022 12:08 PM, JC wrote:
> Actually,
> I don't think anyone understands antenna technology.

Those who have taken the time to study it certainly do. The fundamental 
concepts have been well understood for a century, and the math for two 
more.

Harold Beverage invented the antenna bearing his name in 1921. The 
antenna we call a Yagi was invented in 1926 by the Japanese engineer 
Shintaro Uda, with a lesser role played by Hidetsugu Yagi. Yagi had the 
better press agent. Complex multi-tower directional antennas were in 
wide use on the US AM broadcast band in the '30s, and they were not 
Yagis -- design variables were (and still are) tower spacing, 
orientation, amplitude and phasing of drive currents. As an EE student, 
I worked in the office of Pete Johnson, whose consulting practice was 
the design of these antennas. He and Carl Smith re-wrote FCC AM 
technical regulations after WWII.  The turnstile is a relatively new 
one, invented by legendary engineer George Brown in 1935.

The oldest engineering textbook in my collection is by Stanford prof 
Frederick Terman, published in 1937, and it wasn't the first edition. It 
provides all the math needed to design those vertical arrays, as well as 
long wires, Vee-beams, and Rhombics. During WWII, Voice of America 
shortwave stations had multiple Rhombics beaming to different parts of 
Europe and Northern Africa, and the one I toured in my last year of EE, 
midway between Dayton and Cincinnati, had two Sterba Curtains, patented 
in 1929. The Bruce Array also dates from the '20s.

The Wave Equations, which describe all sorts of vibration, were 
developed by French and Swiss scientists in the mid-1750s. They predict 
the behavior of sound and radio waves, vibrating strings, musical 
instruments, antennas, transmission lines, and light.

73, Jim K9YC