On Feb 27, 1:10�am, "Dave" wrote:
Need to wind a toroid with a center-tap. *Have seen this somewhere, but
can't remember where and can't find it. *Anyone know how to easily wind a
tap into a toroid? *Am thinking maybe put a loop at that point with a twist
in the wire to keep it from slipping back onto the toroid and loosening the
other windings. *Anybody have any ideas on this?

Besides a bifilar winding, which has already been suggested, try this:

Start at the middle and work towards the ends.

Say you need 10 turns center tapped. Take a piece of
wire long enough for 10 turns, find the exact halfway point,
scrape off the insulation there and make a twist. Then put the twist
on the outside of the core, and wind one end 5 turns one way around
the core, and the other end 5 turns the other way.

Or, use two pieces of wire long enough for 5 turns, Wind the first
one, bring its end out, twist/splice to the second one, wind 5 more
turns.

73 de Jim, N2EY