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Incoming radio wave polarisation
Sorry, of course you're right. Thanks for the correction. I apologize
for the (repeated) error. Roy Owen Duffy wrote: Roy Lewallen wrote in : .... actually overshoots 276 ohms. Then, after reaching its peak, it monotonically approaches 276 ohms from the high side as you get 120*pi or 377? Owen |
Incoming radio wave polarisation
Examination of the radiation patterns of horizontal HF antennas
(Dipoles, horizontal rhombics, etc.) near the earth confirms that they invariably have zero response at zero elevation on their best azimuths. (Should have made it clear that the antennas were near the earth, not just their patterns.) The earth reflects energy which strikes it at a grazing incidence inverting the phase on reflection. The incident and reflected HF horizontally polarized waves add to zero producing a null along the earth`s surface. I did not include enough detail in my earlier posting so Richard Fry replied: "If this were true (zero response at zero elevation on their best azimuths) then most television stations would have zero field strength near the earth over much of their present coverage areas." If TV station antennas were 1/2-wavelength or less above the earth, their field strengths near the earth would truly be near zero over much of their present coverage areas, VHF, or UHF. Best regards, Richard Harrison, KB5WZI |
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