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Old August 17th 06, 11:32 PM posted to rec.radio.shortwave
RHF RHF is offline
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First recorded activity by RadioBanter: Jun 2006
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Default External Shortwave Antenna OverLoad - Is It A Problem ? - Do I Have It ?


DJ wrote:
"dxAce" wrote in message
...
For your purposes you'd be better off just running a random length of
wire. And
since you're running a portable you probably won't want to make that wire
to
terribly long as you might overload the radio.


overload

My longwire currently goes into a modified DX398 through an input that is
1000 ohm, high impedance. Will overload still be an issue?


DJ,

When you are hearing the same local AM Radio Stations
-or- sometimes FM Radio or TV Stations all across your
Radio Dial and on several Bands then you usually have
External Shortwave Antenna OverLoad; and need to Trim
(cut-back) the size of the Antenna Wire -or- Attenuate
the Antenna Signal coming into the Radio.

The classic sign of OverLoad is hearing local AM Radio
Stations at several spots in the Shortwave Bands.

Then again sometimes it ain't the External Shortwave Antenna :
It is the AM/FM Shortwave Radio that needs fixing or replacing.


DJ - More information is required.
How is the 1000 Ohm Input configured ?


READ - Portable AM/FM Shortwave Radio-to-Antenna
"GIZMOE" Connector Box
http://groups.google.com/group/rec.r...1903626f5e6d70
http://groups.yahoo.com/group/Shortw...a/message/2070
http://groups.yahoo.com/group/Shortw...a/message/1489
http://groups.yahoo.com/group/Shortw...na/message/957
http://groups.yahoo.com/group/Shortw...enna/message/7

NOTE - Improved Circuit and Description :
+ Continuous "Ground Rail" 'tie-in' for All Components
+ Jack-Connector to 'match' the Antenna Lead-in.
+ High Voltage Discharge protection using Gas Discharge Tube
+ Low Voltage Surge protection using Front-to-Back Dual Diodes
+ Static Discharge protection using 10K Ohm Potentiometer
+ + RF Signal Attenuation using the same 10K Ohm Potentiometer
+ Not-in-Use protection using an Circuit "Open" Switch
+ Plug-Connector to 'match' the Radio's External Antenna Input.
http://groups.google.com/group/rec.r...bfe14ab2ec6900

NOTE - If you use the NE-2 Lite-Bulb and on a 'normal day'
the Bulb is always Glowing or Blinking; then Trim your
Antenna by 25 Feet and check it again - repeat as needed.
http://groups.google.com/group/rec.r...6995600a6e2edd


PROTECTING THE "PORTABLE" AM/FM SHORTWAVE RADIO
FROM THE ANTENNA :
If the Radio Listener has their 'portable' AM/FM Shortwave Radio
permanently connected to an Out-Side External Shortwave Antenna.
I recommend that they consider building and using a "GIZMO"
Connector Box between the Antenna and the Radio.
http://groups.google.com/group/rec.r...a9bb618defeca2


READ - "Portable Wire Antenna" (PWA) for your 'portable'
AM/FM/Shortwave Radio
http://groups.yahoo.com/group/Shortw...a/message/1728
"Portable Wire Antenna" (PWA) by Tom Sevart [N2UHC]


hope this helps - iane ~ RHF