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Old September 27th 07, 03:03 PM posted to rec.radio.amateur.antenna
Dave Dave is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 108
Default Probably a stupid question, but...


"Owen Duffy" wrote in message
...
"Dave" wrote in
:

...
were easy to install. Seems I read somewhere that contrary to
conventional wisdom, the shield on a shielded loop doesn't actually
shield at all, but becomes the antenna element. Anyone know anything
about that line of thought? I obviously know nothing, and am trying
to learn. Just don't know where to focus my energies.


I have written a simple explanation on the operation of the so called
'shielded loop' at http://www.vk1od.net/shieldedloop/index.htm .

You may find the article of interest.

If you read and understand the content of the article, you will see the
pitfalls in using tape to 'shield' a loop.

Owen


Hello Owen,

Sorry I am just now getting back to you on this, but I have been reading and
studying your article. I constructed a loop somewhat like the one you
discuss, but have one question: you speak of a "feed tee" from which the
feedline extends. Should I be able to buy such a T-shaped device at my
local parts outlet? I asked about such there one time, and was practically
laughed at. But it seems such would be very handy for antenna builders of
all types. If my local parts distributer doesn't have this item, where can
I get it and what should I call it ("feed tee"?)

The loop I constructed is extremely primitive, but still functions nearly as
well as the 110' longwire antenna I have used for years. And it is
*directional*, though sometimes noisy (probably because the feedline does
*not* exit and travel symmetrically away from the loop, I am guessing.)

The main way in which my loop differs from your design (other than the
feedline asymmetry) is the fact that the shield is not cut away from the
center conductor opposite the feed input. Can you tell me what function
this feature serves?

Thanks for your help.

Dave