[TowerTalk] Coax, conduit and toroids

Rick Kiessig kiessig at gmail.com
Thu Jun 28 08:16:28 PDT 2012

Speaking of toroids, can someone point me to a good set of design rules for
true current-type (multi-core) baluns / impedance transformers, of the type
you might use to match a range of dipole-type antennas to 50 ohm
transmission line? I'm looking for things like how to choose wire size, core
size and the number of toroids for a given power rating, how many turns to
use, and that kind of thing. Jim K9YC has suggested low-permeability cores.
My interest is 3 MHz to 50 MHz, so Fair-Rite #67 looks like it might be

I've spent quite a few hours searching the net for designs, and found lots
of confusing and conflicting information and advice.

73, Rick ZL2HAM

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