[Elecraft] Toroids, A logical approach - Winding sense, Counting turns

[Tony Fegan VE3QF]

Most of the problems encountered in toroid winding seem to be, getting those
first couple of turns going in the right direction. The key to this is to
think in terms of a screw thread (99.99 % of screws have a right hand
thread). First, determine whether the winding is to be wound with a
right-hand thread or a left hand thread. This is easy to see on the winding
diagrams in the manual. Once the second turn has been wound you can check to
see if the winding is going to have the correct thread and if it is wrong it
can easily be corrected. Thinking in terms of a screw thread is less likely
to lead to mistakes, as it does not matter which way you look at the
winding. I find thinking in terms of clockwise and anticlockwise, and, is
that with the winding going away from you or coming towards you, to be most
confusing.
The second turn of the toroid can be to the left or to the right of the
first turn. One way gives you a right-hand thread and the other gives a
left-hand thread. It's that easy. I like to push half of the recommended
wire length, through the core. Next, I bend the ends up so that the core is
supported when the ends of the wire are held up together. Grab the core
between thumb and forefinger, making sure that the wire is also held firm.
Wind a second turn in the correct sense (right or left-hand thread). Pull up
the wire end to tighten the turn. If the wire is stiff or the core is small,
then it helps to press the wire around the core before it is pulled through,
so that it fits closer. Don't waste time counting turns. Continue to wind
one side until there is about 1 1/2 inches of wire left, keeping the turns
fairly close together. Repeat for the other end of the wire. Now, lay one
end of the wire flat across the top of the core and the other wire coming
out of the center of the core (the ends will be in the same direction). Now
is the time to count the turns. I usually count in fives. Start at one end
and count five turns of wire on the outside of the core. Make a small gap in
the winding with your fingernail. Count five more on the outside and make
another gap. Continue to the end. Total the turns and then add or subtract a
turn or two as necessary. Note that the number of turns through the core is
the same as the number of wires on the outside, only if both wires come out
the same side of the core. Try winding 3 or 4 turns on a spare toroid core
to check this out. The next step is to spread out the turns until they are
evenly spaced around the core, occupying the percentage of core as stated in
the manual. Spreading the windings also tightens them up thus making a neat
looking toroid.
Finally use your favorite method of stripping and tinning the wire ends,
making sure that they are tinned close enough to the core. I like to strip
my wires with a cigarette lighter followed by sanding with emery cloth.
Adding a little extra flux helps the tinning process.
You really should enjoy winding toroids. Sure it takes a little time, but a
change of pace doesn't hurt. My hands shake (some numbness as well) and my
eyesight is not that good so I have to take my time but I still get great
satisfaction on the completion of each toroid.
Maybe a note could be added to the toroid diagrams in the manuals to denote
the winding sense (RHT or LHT).