"Roy Lewallen" wrote:
As I'm sure you know, AM broadcast antennas intentionally radiate
very little sky wave, and that's what amateurs need for communication
beyond a few miles. Some care must be used in comparing MW
broadcasting requirements and characteristics with amateur
HF communications.
__________________

AM broadcast station verticals have very significant energy at elevation
angles that can be propagated by skywaves. As I'm sure you know, Class A AM
broadcast stations have an extended geographic service area served
exclusively by their nighttime skywave--many times more area than is served
by their surface wave, in fact.

Richard Clark's statement did not limit his conclusion to amateur HF
communications.

RF