Right, typically a couple hundred ohms. Modeling the base Z of a thick
broadcast tower is very difficult with MoM software. Changes in thickness
can result in large base Z changes.
Just to be clear, since the discussion drifted to half-wave radiators, my
comment above was specific to the modeling of thick v. thin half-wave
radiators, including the 180-195 degree radiators of some well-known 50KW AM
stations. The results when modeling the base Z of approx. 1/4-wave
radiators is less affected by thickness, probably due to a lower base Z to
start with.
Paul, W9AC
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Topband reflector - topband@contesting.com
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