Richard Clark wrote:
. . .
Stuff the (insulated paired) wires through the ferrite bead/torus/tube
just like you would a coaxial line. Total length of ferrite (a
combination of about 40-60 beads or equivalent) on the order of a
foot. A large torus can support several wraps through it to the same
effect.

Bear in mind that the impedance of multiple turns is proportional to the
square of the number of turns. So 5 turns, for example, through a single
core gives you the same impedance as 25 cores strung along the line.

Roy Lewallen, W7EL