[TowerTalk] radials redux

[Jim Jarvis]

The early work on ground systems under vertical antennas was
performed at AT&T Bell Labs, in the late 30's.  They had a site
in Sussex County where much of it was done.  Some also happened
at the Whippany site, and some near the Jersey Shore.  

This work described efficiencies vs. # radials, vs. earth 
conductivity and soil types.  It was reported in their internal
journal.  

I read this stuff when I was in college, and have forgotten much
of the details.  What stuck was the fact that 120 radials should
give you 98% efficiency...and over halfway reasonable earth, 16
radials would bring you to 85-90%.  

It is also possible that RCA engineers did similar, parallel 
work, around the same time.  It is also possible that they reached
somewhat different conclusions, given the state of instrumentation
at the time.   

Jim N2EA