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Old January 14th 04, 07:48 AM
diddo
 
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Default Computer Noise

Everytime I turn on my Pentium-4 PC, my shortwave signal gets completely
buried behind the noise. Beside shutting off the computer, what can I do to
eliminate this noise?

Thanks


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Old January 14th 04, 08:36 AM
brun
 
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Try changing your monitor resolution, for example to 1024x768.

Move your radios away from the computer and monitor.


"diddo" wrote in message
...
Everytime I turn on my Pentium-4 PC, my shortwave signal gets completely
buried behind the noise. Beside shutting off the computer, what can I do

to
eliminate this noise?

Thanks




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Old January 14th 04, 08:47 AM
CW
 
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Go over to your nieghbors house to do your listening. Make sure that he
turns off his computer.

"diddo" wrote in message
...
Everytime I turn on my Pentium-4 PC, my shortwave signal gets completely
buried behind the noise. Beside shutting off the computer, what can I do

to
eliminate this noise?

Thanks




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Old January 14th 04, 12:31 PM
Rick Kunath
 
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Try turning off and *unplugging* your monitor from the AC power, while the
comouter is left on.

If this cuts down drastically on the noise, take a portable radio to your
favorite comouter store and test some flat panel displays. Many of these
are much less prone to interfering with radios than CRT based monitors.

Rick Kunath
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Old January 14th 04, 12:50 PM
starman
 
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Jack wrote:

On Wed, 14 Jan 2004 00:48:03 -0700, "diddo"
wrote:

Everytime I turn on my Pentium-4 PC, my shortwave signal gets completely
buried behind the noise. Beside shutting off the computer, what can I do to
eliminate this noise?

Thanks


Shut of the radio. g

Seriously, move your antenna outside, or as far from the computer as
possible and feed it using coaxial cable.


It's hard to use a portable radio with a whip antenna in the same room
as a computer or television. It will pick up a lot of noise. Here's what
I did to eliminate the noise (URL-below). It requires building an
antenna system outside with a good (RF) ground.

http://www.anarc.org/naswa/badx/ante...e_antenna.html


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Old January 14th 04, 12:55 PM
CAndersen
 
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Changing your monitor resolution and/or refresh rate (if that last
adjustment is available to you) is an excellent suggestion. Each setting
generates a different set of interference frequencies, and one may be
compatible with SW listening.


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Old January 15th 04, 01:18 AM
matt weber
 
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On Wed, 14 Jan 2004 00:48:03 -0700, "diddo"
wrote:

Everytime I turn on my Pentium-4 PC, my shortwave signal gets completely
buried behind the noise. Beside shutting off the computer, what can I do to
eliminate this noise?

Thanks

The usual culprit is the monitor. Most of the Big ones are class
A,not Class B, and I have never seen a Class monitor that actually
operated within the Class A FCC limits (and I've been out on a test
range many times). The other possible source is the switching power
supply, but most of them are very heavily shielded if the computer is
class B. (All laptops are class B, and in theory anything designed for
home use is class B).

Everything else operates at clock frequencies far beyond the HF
bands.

CRT monitors however user a very high power saw tooth to drive the
sweep, and you can think of it as a very messy 100Khz calibrator. Most
are on the order of 100Khz, and the wave form is very rich in
harmonics (do a fourier analysis on a saw tooth), and the output of
the Horizontal osicillator is usually tens of watts, so even if the
harmonics in the SW band are 50 db down, that is a lot of power next
to a shortwae that is trying to receive nanowatts.

So get yourself an LCD display.
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