On Mar 6, 6:07 am, "Richard Fry" wrote:
wrote:
I agree. I think it's quite possible that even a decoupled feedline
will add enough radiation to make the antenna noticeably better
than it really is. I'd prefer to see the source mounted *at* the
antenna to make it a decent comparison.

__________

Unless this antenna is itself balanced, most likely for best efficiency when
operating in this configuration there would need to be a conductor running
from the elevated tx chassis to a good r-f ground of some kind, either
buried in the earth or in the form of a counterpoise. Radiation from that
"ground" conductor could be many times greater than from what is considered
to be the antenna -- even though no feedline is present..

This is a common configuration used for so-called Part 15 AM installations
to get greater groundwave coverage from the 100 mW tx input power allowed
under FCC Part 15.219, by ignoring the 3-meter limit on the length of the
radiating structure given there.

RF

For some reason, I'd always got the impression that the antenna
was symmetrical and balanced.. But who ever knows for sure
with Art...
If this is the case, I wonder why he needs the garbage can lid, or
whatever metal he is using under it..
I had the impression in his various posts that he was trying to
avoid ground connections. But whoever knows for sure except
Art, and now maybe Denny... :/
MK