On Oct 31, 7:50 pm, Roy Lewallen wrote:
Jim Lux wrote:

. . .

And while it can calculate feedpoint impedance vs frequency, which any
number of programs can plot, that's not radiation resistance.

Unless you set all the losses in the model to zero.

Roy Lewallen, W7EL

What about folded dipole vs non folded dipole? Rrad is the same, but
Zfeed is different, even in the lossless case. Or any antenna where
there's some built in impedance transformer (stubs, lumped components,
etc.)