Good Day,
Thank you for the step-by-step description, Craig - and for the burst of laughs I had over this:
"Any way you look at it, winding 1400 turns of hair thin wire is a royal pain in the ass ;-)"
Cheers,
Magnus
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Hi Dave
I took alas no photos. But what I did was:
(a) Buy the cheapest manual coil winder from eBay. In US-speak we're talking $20.
(b) Found a regular pot core bobbin that would fit the core centre leg. That fortunately had lots of
pins.
(c) Wound using wind-and-retrace. If you wind back and forth, you get twice the voltage at each end of
the wind (found the technique from a google search).
(d) Covered each winding layer with a layer of thin yellow transformer tape both for insulation and to
level the wind.
(e) The additional core pins came in handy because I broke the 0.08mm winding wire three or four
times. So I took the wire out, terminated at a pin, and kept winding.
(f) On completion I potted it in a mix of paraffin candle wax and beeswax. I used something like two
thirds candle (and I mean that I melted candles) to one third (carpenter's) beeswax - which you get as
a solid stick.
(g) After assembling to the core, I immersed it in the molten wax until bubbles stopped, and let it
soak for 15 minutes more. Then let it drip until cold.
The pot core needed to be modified, because it was too long. So I cut off the end cheek, then reduced
the length of the centre tube and reattached the end cheek with superglue.
Any way you look at it, winding 1400 turns of hair thin wire is a royal pain in the ass ;-)
The first attempt was a learning process. The second one is in the 576 and working perfectly.
Craig
