[Elecraft] Toroids frequency range and baluns

[Ron D'Eau Claire]

Jim wrote:

WRONG! There are three fundamental cases of ferrite "baluns" or chokes. 1) A

choke wound with coax  2) a choke wound with parallel wires (bifilar)  3) a 
transformer (voltage balun). 

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You are absolutely right Jim. I read current balun and thought choke balun.
I missed the 4:1 comment. 

"Balun" is an unfortunate, all-inclusive and misleading term. One so-called
"balun" may be as different from another "balun" in its requirements and
application as a motorcycle is different from railroad locomotive. 

I stand by my statement when talking about a "choke balun" consisting of a
string of ferrite beads on some coax or a coaxial line on a coil form such
as I  described. The only losses caused by such a balun will be those of the
transmission line itself, which cannot be ignored if the SWR is high.

So-called "baluns" that transform impedances are, typically, transformers --
often transmission-line transformers. They're a whole different animal and
can be very unpredictable, especially when they use ferrite or powdered iron
cores and are exposed to a wide range of impedances.  

Ron AC7AC