Total posts : 45366
Hi Guys (and also all the Gals here),
Rich surely provided a scholarly presentation on this topic and I don’t have much to add except that I read somewhere where the function of a “top hat” is to alter the current distribution in the radiator such that the current is increased or “raised up” in the body of the radiator relative to a non “top hat” antenna.
Rich’s numbers indicate some difference, and the legalities could be discussed forever, but technically it doesn’t appear to me that there is much advantage in practical range by employing these hats. Perhaps when the radiator is a significant fraction of a wavelength it is worth while but though I see no harm I see no real advantage.
By the way, has anyone heard of a “Slinky” antenna? Rich, your program would probably like this. I know you have simulated a helix but have you tackled a genuine Slinky, perhaps center fed or link coupled?
Neil
