RadioBanter - View Single Post

February 5th 05, 12:54 AM

wrote:
I picked up some ferrite cores today and have been attaching them to
power cords, computer cables and my coaxial feedline. I can report a
definite reduction in noise. This is especially gratifying because
ferrite cores aren't too expensive.

Any advice about how to position these cores? Are they best placed
close to the electrical outlet or close to the computer, receiver or
device being used (or both)? Would appreciate your insights.

Thanks....Steve

I have found that I get the most noise reduction by
placing them as close to the RFI source as I can get.
I have found a very good source for ferrite "beads",
your local PC/TV repair shop. They often have lots of dead
VGA monitors, keyboards, mice etc. Almost all of these
have ferrite RFI supression one the cables. I wangled
permssion to cut the cables with the big blobs of plastic
off flush with the device. For the smaller items, mice,
keyboards, older hand held parallel scanners etc, I had
to agree to haul the "junk" off.
A little careful work with a sharp knife and you can
extract the ferrite beads. They, for th emost part,
aren't the type that snap togather, but I am willing to
replace a few connectors to get some quite.
Lots of RFI supresion for cheap.
Th efew snap apart feritte beads I got I used for
keyboards, my VGA monitor and other hard to replace
connectors.
I found that palcing several (10) on the coax that
carries my SW RF in I knocked the last RFI from the PC
down to "yea it's there, but it isn't a problem".
Terry