[RFI] Ferrite bead disintegration

[VE3YV George]

Had a similar experience with a 50 bead balun (choke) on a low dipole 
where the beads were slipped over the coax and not protected from 
flexing.  I took off the plastic sleeve cover and found a lot of dust 
and small fragments.  Definitely not lightning or high transmit power 
(max 200 wts) damage.  Assuming two years of wind creating enough flex 
to bang them against each other - ceramic is brittle - and as a few 
beads break, then more room for the others to bang into each other...  
However, this is speculation as I haven't taken apart the bead choke 
using the same materials on my beam that is enclosed in a PVC tube and 
can't flex to verify that's the root cause.  Some day I'll replace it 
with the better design from Jim, K9YC, and then get inquisitive.

73,  George  VE3YV / K8HI