Art wrote:
"That is because you quote outdated technology and have lost the means
of deduction for yourself."

O.K, Not much technical content in that posting, nor hint of what Art
hopes to do with an 80 degree tilt. Maximizing horizontal polarisation
is another mystery. Vertical polarization is the way to launch
groundwaves and it will be so 100 years from today. Modern technology is
unlikely to improve the FCC approved antenna and grounding systems used
in AM broadcasting, thanks to RCA`s B., L., & E. (1927).

The coil argument has persisted a long time but it has provoked some
searching into the behavior of inductance. W8JI may be on to something
but he may not have it exactly right. Terman and Lenkurt have the TWT
down, as invented in England (1943) but its coil is stretched out so
that a foot long coil only has a dozen turns and lacks tight coupling
which might work as W8JI describes.

Best regards, Richard Harrison, KB5WZI