RFC and Telamon,

RF "Choke" Ferrite Material Info :
REF = http://www.mouser.com/catalog/623/660.pdf

From what I understand most of the pre-assembled Ferrite
Materials are Type # 43 to kill the lower frequency Noise
associated with power lines and electrical devices.
These lower frequency Noise Sources often have many
Harmonics across the High Frequency (Shortwave) Band.
They work well because they reduce the primary Noise
Source Frequency and most of higher frequency Harmonics.

If, however you feel that what you have is a Noise Source
that is not simply an Harmonic of a lower frequency primary
Noise Source. Then one of the other Ferrite Materials like
Types # 31 or # 61 may be the answer if in-fact the Noise
Source is being generated at some higher frequency.

Unless you have the test equipment to truly determine
which of the Noise Sources you have : Then this is simply
a process of trying One-at-a-Time as see what the results
are . . . . YMMV )


iane ~ RHF
http://groups.yahoo.com/group/Shortw...a/message/6093