Roy Lewallen wrote:
Jim Lux wrote:

The other factor is core saturation.. flux goes as the
voltage*frequency ... so 10:1 VSWR means you might have 10x voltage..

At HF, the ferrites which are best to use for baluns will go up in
flames due to loss at flux densities well below saturation.

Roy Lewallen, W7EL


Well then, same general idea.. lots of volts = lots of flux = lots of
dissipated energy from the core loss...

And, of course, not all baluns are made with appropriate materials (e.g.
using a lossy EMI suppression mix might be fine in a "choke"
application, where high Z is keeping the current low.. but terrible in a
transformer type situation, where you have a lot of flux in the core)