Jeff,
Could you please explain what you mean by "end-to-end"? There are four "ends"
in the CMC and I'm trying to understand which ends you are referencing --
input-pair to output-pair, or between in and out of one wire, or...?
I mean, voltage applied to those 12 turns. Short the input pair to make one connection, short the output pair to make the other connection, apply the voltage between those two points.
In a "textbook" antenna installation, such as a perfectly symmetrical horizontal dipole, symmetrically over ground, with the feedline coming down straight and vertical, no other objects nearby, and fed from an unbalanced, perfectly grounded transmitter, with the dipole impedance and cable impedance being identical and the CMC's impedance being infinite, the voltage appearing end-to-end on a CMC used as balun is one half of the transmitter's output voltage. In a typical practical installation it's usually lower, but with some bad luck it could also be higher.
Also, why 170V RMS?
Because the applied voltage defines the flux density in the core, along with frequency, number of turns, and core dimensions. And for the core size (FT-240) and turns number (12) considered here, 170V at 1.8MHz results in a flux density of about 11mT, which for this particular core material (31) results in a volumetric loss of roughly 300mW per cm?, which I somewhat arbitrarily defined as a reasonable value for intermittent service.
And I made the calculations at 1.8MHz because it's the worst case. On higher frequencies the loss gets lower.
Manfred
