RE>Mail failure 3/24/98
RE>rfi-digest V1 #42 3/24/98
Ed, K0il, writes
>>...The 2 inch long ferrite clamp on "beads" sold by radio shack are about $3
>>or $4 each. I used about 25 of them on the Stereo and 10 more on the leads
>>from the computer to mouse and keyboard and monitor." <<
These ferrites are usually not very effective at low frequencies. Just as a
rule of thumb, I'd count on 50 to 100 ohms at 100 MHz and near ZERO ohms at 10
MHz for one pass of wire through the core.
Where this many were needed, it is likely the same result could have been
obtained by top-quality shielded cables, adding grounding clips inside or at
the computer, adding additional shield over the existing cables, or
combinations of these measures. 25 ferrites is a LOT of money, especially at
Radio Shack's retail price.
Cortland, KA5S
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