Hi Earl,
> Tom's (W8JI) design uses a 73 material "binocular" core, with a 2-turn
> primary (#29 AWG) and an 8-turn secondary (#26 AWG) wound on top of the
> primary. Tom said, "The core is about 1" long and 1/2" thick, and is
> commonly stocked". (By whom?)
Ameritron uses them, PN 412-5250.
Fair-Rite corp makes them, P/N 2873000202.
I had the dimensions wrong. I eyeballed it. They are just over 1/2 inch
long. That gives over 1" of ferrite around the winding in a single turn.
The winding was #26 both primary and secondary, size isn't important as
long as it fits and the wire doesn't break easily.
Additionally, you could use these cores with a bifilar winding as a common
mode choke. Five passes through the holes would be a few thousand ohms
series common mode Z. I use them on loops.
FB-73-801 or 2673801 beads work also, if you stack them. A one or two inch
stack is fine.
73 Tom
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