[Elecraft] OT: "Flat" ferrite clamp-ons for window line

[Jim Brown]

Guy,

Look at Fair-Rite 2643167851  This MIGHT allow several turns of some 
smaller window line, maybe enough to be useful at HF. Remember that you 
need a complete magnetic circuit, so this makes it unlikely that ferrite 
parts designed for ribbon cable will fit your need.

I assume you're attempting a common mode choke.  Take a look at the 
latest version of my RFI tutorial, which shows some very nice medium 
power HF common mode chokes having a Z of about 100 ohms wound on #31 
toroids with #14 THHN.  You could raise the impedance by spreading the 
bifilar pair a bit.  Unlikely you'll achieve a perfect match, but we 
both know that's probably not a deal killer for a section of line that's 
less than 1/30 wavelength at the operating frequency. :)

http://audiosystemsgroup.com/RFI-Ham.pdf

73, Jim K9YC