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Old December 8th 07, 05:05 PM posted to rec.radio.shortwave
Steve Steve is offline
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First recorded activity by RadioBanter: Jul 2006
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Default A Beginners Question

On Dec 7, 8:57 pm, "Dale Parfitt" wrote:


I would not be quoting some hamıs web site as an authority on
electromagnetic theory or folklore.


You might want to Google Tom W8JI and find out who he is. To describe one of
the U.S.'s brighter engineers and designers as "some ham" is a real
disservice. The fact that he happens to have a ham license is purely a
coincidence. His explaination of how the shielded loop functions is embraced
by the IEEE group on Electromagnetics and Propagation, Roy Lewellen (writer
of EZNEC software) et al.
W4OP


W8JI's view, as I understand it, is that small shielded loops are no
less susceptible to local noise in virtue of their shielding, since
the shield, in his view, is part of the antenna. It's probably worth
pointing out that, even if this is true, it is still consistent with
the view that small loops pick up less noise than other types of
antennas in virtue of their directional characteristics. I guess W8JI
would then maintain that a shielded loop would be no less susceptible
to local noise than an unshielded loop, since in this case both
antennas enjoy the benefits of directionality; but he isn't commited
to denying that loops are quieter than, say whips when all things are
considered. Is this correct or am I missing something here?