Topband: "T"-Top Vertical Antennas

[Paul Christensen]

For the historians on the list, one of the first amateur radio transmissions 
heard across the Atlantic Ocean occurred during the sponsored ARRL 
transatlantic tests in 1921-1922.  Station 1BCG in Greenwich, CT used a 
modified "T"-top Marconi vertical at a height of 70 feet.  The top-hat span 
was 100-ft.

The classic Marconi-fed system was modified in the sense that the base-fed 
antenna was not referenced above an earth ground or a buried ground system. 
Instead, Armstrong and Cronkhite used a resonant elevated radial system at ~ 
10 feet above ground.  In the link to the photo below, you can clearly see 
the elevated radial system located to the top and rear of the "shack."

http://users.erols.com/oldradio/eha47.htm

I had thought that elevated radial systems were a recent revelation of the 
past couple decades.  So, when I recently read a detailed description of the 
1BCG antenna system  I was surprised to learn that elevated radials were 
employed ca. 1920.  This was well before the buried-ground radial research 
conducted by Brown-Lewis-Epstein in the early '30s.

With 1BCG's 70-foot radiator, 100-ft horizontal top-hat, and extensive 
elevated radial system, I suspect that antenna would provide a "gangbusters" 
signal by today's standards.

Paul, W9AC