Mike,
> A second question, the BN-73-202 cores I use are conductive to a
> small extent. I have read it is better to use insulated wire or use
> sleeves in the cores.
You should use either enameled wire or something
like the wire-wrap wire that Radio Shack (used to?) sells.
See below on how I use enameled wire.
/>I noticed there was about 2.5K ohm between
> the core and any of the windings.
Your winding is shorted to the core and there
could be even a shorted turn.
> I assume some of the insulation
> go scrapped off the enamel on the wire I was using.
Yes, that's what happened....sharp edges at the
ends of the holes can slice right through enamel.
> I am moving to
> insulated wire although that limits the number of turns.
Use the wire-wrap wire or "Kynar" wire...it's #30 with a thin,
tough insulation....could be Teflon. A small diameter probe,
something like a toothpick, will help pack the wire in the
core if your need a lot of turns.
On using enameled wire...I insulate the holes in the cores
with ordinary plastic soda straws. I cut them just a little longer
than the length of the core and then slit them lengthwise
with small sissors. Then I roll them in my fingers, observing
how much excess there is in the "roll" when inserted into the
core, then I cut off most of that excess, leaving some overlap.
I re-insert the roll into the core and it's ready for use.
73,
Charlie, N0TT
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