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Author Topic: Spurious HF signals from my computer monitor  (Read 1942 times)
K1AF
Member

Posts: 15




Ignore
« on: December 13, 2005, 07:57:31 AM »

I wish to know how to eliminate spurious HF signals in my receiver which disappear when my computer monitor is turned "OFF"
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WB6BYU
Member

Posts: 17790




Ignore
« Reply #1 on: December 13, 2005, 01:16:12 PM »

Move the computer monitor further from the receiver.

Add more ferrite cores/shielding to the wires connecting
the monitor to the computer.

Shield the whole monitor with aluminum foil, or put it
in an aluminum box.

Turn off the monitor when you want to listen to HF.


You can make a small antenna probe and use it to sniff
around the monitor to find where the signals are leaking
from.  You could be hearing harmonics of the switching
power supply, possibly radiated from the power leads.
Or they could be related to the sweep circuit, which can
be radiated through the display screen.  Try 4 or 5 turns
of wire about half an inch in diameter on the end of a
length of coax, and move it around the case until you
find the strongest point.  If the signal is too strong,
reduce the diameter or number of turns on the coil.
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