Owen Duffy wrote in
:

....
Everybody, and every manufacturer has a recipe for common mode chokes,
but if you do not provide a plot of common mode impedance, preferably
R and X separately, then you might reasonably question the recipe.

Aargh!

Everybody, and every manufacturer has a recipe for common mode chokes, but
if *they* do not provide a plot of common mode impedance, preferably R and
X separately, then you might reasonably question the recipe.