Yet another reason why I really don't like the word "balun" to describe
a component. The problem is that the "BALenced to UNbalanced"
contraction is used to describe at least a dozen different things that I
know of. You can, for example, buy electronic devices to put analog
video on twisted pair, and they are called "baluns." A half-wave section
of coax that feeds both sides of a dipole against the center is called a
"balun." A two-winding transformer wound on a ferrite core where the
core carries the magnetic field is mistakenly called a "balun," but it
is really a TRANSFORMER. And so on.
Jerry had it right when he called a sub-set of his designs "transmission
line transformers."
But it is simply wrong to call turns of coax or a pair of wires wound
around a ferrite core and connected as a transmission line a
"transformer" -- it is a common mode choke. The same physical pair of
wires could be wired as a 2-winding transformer, but we would want the
core to have low loss (for example, #61 for low HF, #67 for higher HF).
And it's a TRANSFORMER, not a "balun." :)
Now, when we use the right words to describe things, it's FAR easier to
know what they are and understand how they work.
BTW -- I didn't come to this conclusion right away -- you'll find the
word "balun" in my 2007 RFI tutorial. One of these years I'll get around
to an updated version. :)
73, Jim K9YC
On Wed,6/29/2016 1:49 PM, Cortland Richmond wrote:
Cores I dealt with working in EMC were usually Fair-Rite 44 or
Steward/Laird 28, not especially low-loss cores either, but quite
common at Hamfests. I might see what I can do to replicate the design
with 4:1 Ruthroff followed by a 1:1 Guanella.
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