RF choke ferrite materials

Hello all.

Recently Mike Hammer posted on the Tesla-2 list an interesting address:


It seems like they have in stock large ferrite toroids, at a feasible price ($
10 - 15) and no minimum order. This is a rare case, in my experience.

Now my questions, about building a couple of protection chokes to be connected
between the tank and the primary circuit.

What kind of ferrite material should be selected? An iron-powder (mu about 10)
to avoid saturation at high currents or a wide-frequency ferrite with a higher