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Subject: It may not be ferrite; but...
Priority: normal
In-reply-to: <m0yHYNB-000ZmwC@mgate.arrl.org>
Probably nothing new, but original for me.
I use deflection yoke cores from junk tvs to decouple feedlines, power
supply leads, computer cables, etc. They are bulky, even from a small tv, but
have worked well for me. Multiple passes of the cable are possible to achieve
high isolation reactance and the power handling capabilities for brute force
isolation has merit.
As for material type, technical characteristics and efficiency; it is no
concern to me as the cores are free and work for my various applications.
I strip off the plastic and wire, and save the clips or clamps that hold the
halves together. I then reassemble the core assembly, using the clamp hardware
or long nylon tiewraps or electrical tape. I then wrap the sharp edges with
good quality tape. I wrap my flexible cable through the assembly as desired. I
assemble them around my hardline, as I get them, as a stack of large 'beads"
They can be used indoors and out.
My open wire fed 75 m dipole passes over the shack, some 30' above. My
shunt fed tower is 3 feet away from my equipment. I operate hf, vhf and uhf
with the typical 50 to 100 watt levels with no rf related gremlins in
the shack. I sometimes run the legal limit on hf and operate the computer at
the same time, without grief. As for most folks my rf ground system is poor
but extensive cable "choking" has enabled me to operate all mode, analog and
digital with virtually no grief.
They are quite effective for killing emi radiating from scr and triac
controller power cords, swiching power supplies, etc. They have never failed
to keep rf out of my power supplies, when all leads were choked with a core.
Touch control lamp cord "choking" has been very effective. I have used them
for eliminating rfi in telephones, vcrs, stereos, tvs, blah, blah, blah.
I have never checked to see how conductive they are to the typical dc and ac
voltages used in the shack. You are warned!
I am sure, for those that wish to give my suggestion a whirl, there will be
many happy customers, but as always, your milage may vary. Posted details of
successful problem resolutions with similar or described techniques might
be of value to others.
Pete/wa4hei
The meek will not inherit the Earth.
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