[RFI] Choosing Snap-On Toroid for 6M?

Morse, Earl (E.A.) emorse at ford.com
Mon Feb 19 15:08:33 EST 2007

As folks have already noted, the material type is not mentioned in the
data on that site.  In most cases these snap on beads are in a #43
material which is used almost exclusively by the computer industry for
snap on beads because the radiated limits start at 30 MHz and this
material is best suited for the 30-200 MHz range.

Since these beads are common they are also very cheap.  Especially when
you get them off of junk box computer cables.  At 50 MHz you won't
notice a whole lot of difference in impedance between the #31 and #43
for the same size bead.    

In selecting sizes of bead you may want to use a larger bead and use
multiple turns or fit the bead to the size of the cable.  I prefer the
solid beads but realize the issues of getting them on cables that can't
be disconnected.  There is some loss of impedance due to using a split
material vs a solid material but I can't remember how large it is.

Try what beads you have around the junk box as they are probably #43 mix
and see how they work.  Then see if you can improve by ordering other

Good luck.

Which of these snap-ons might be most likely to
stop a problem I have with 6M getting into my
LDG AT-100Pro autotuner, please?


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