LF,
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An "On-the-Roof" Shortwave Antenna may be a good idea;
and an "In-the-Attic" Shortwave Antenna can also work well.
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But when you have RFI / EMF Man Made Noise Problems
usually one sure way of reducing them is to use a Loop
Antenna to Null-Out the Noise Source or Peak the Signal
of the Radio Station you want to listen to.
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An In-Door Loop Antenna is about as easy to build and
takes about the same amount of time money and effort
as an Out-Side {External} Shortwave Antenna.
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READ - Four 'different' "In-Door" Loop Antennas Ideas
http://groups.yahoo.com/group/Shortw...a/message/1933
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Specifically take-a-look-at the : In-Door "On-the-Wall"
Loop Antenna for 'portable' AM/FM Shortwave Radios that
use a 1/8" (3.5mm) Jack for the External Antenna like your
Roberts R861 Radio.
http://groups.yahoo.com/group/Shortw...a/message/1845
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This Antenna can be Mounted with Two Cup-Hooks
and a 8oz Fish Weight to position the Bottom-Center.
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Try it on one wall and then the adjacent side wall (90*)
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iane ~ RHF
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All are WELCOME and "Invited to Join" the
Shortwave Listener (SWL) Antenna eGroup on YAHOO !
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
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Some Say: On A Clear Day You Can See Forever.
http://groups.yahoo.com/group/Shortw...na/message/502
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I BELIEVE: On A Clear Night . . .
You Can Hear Forever and Beyond, The BEYOND !
With a Shortwave Listener SWL Antenna of your own making.
"If You Build It {SWL Antenna} You Will Hear Them !"