[Elecraft] OT: Big Ferrite Split Beads @ B.G. Micro

[Craig D. Smith]

I'd like to follow up on K2AV's excellent recent post.

Thanks to K9AY's previous work, I also was turned on to the type 31 material
for RF suppression at HF.  I have found it to be substantially better than
type 43, especially on the lower bands and for broadband use.

A hint for those of you who are contemplating placing an order for some of
the clamp-ons:  The smaller diameter clamp-ons look attractive at first
glance due to their low prices and ability to fit most of the small cables
in your shack.  But remember the choking impedance goes with the square of
the number of turns.  A more expensive core with a larger aperture will be a
much better bang-for-the-buck.  For example, a core that allows 3 turns of a
given cable will be 9 times more effective than a single turn core and might
only cost only 50% more.  Needing to use several single turn cores adds up
quickly cost-wise.

I use lots of the 0431164181 clamp-ons here.  They will accommodate one pass
of RG-8 size coax or several turns of computer cables, audio cables, etc.
For example, it will allow 6 or 7 turns of RG-174.

73  Craig  AC0DS