Progressive wind step example

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TerryG

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Sep 18, 2021
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Wow!!! Well I watched a few other of that guys videos he is BRILLIANT!!! Some people have intellegence and patience to go along with it. His counter was an idea I had several years ago, then I though a mechanical one with micro switch might be more accurate. Each have their advantages and disadvantages, but for what he and I would be doing both are fine for hand winding.

Does anyone know why on RF chokes like that you want the windings patterned like that, what does that do for the choke?
 

Tubetec

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Nov 18, 2015
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The universal wind produces a self supporting structure , lower capacitance appears to be the main benefit compared to a standard coil .
Special cotton wrapped magnet wire is used
 
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TerryG

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Sep 18, 2021
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California USA
Tubetec,

Curious what benefits "special cotton wrapped magnet wire" has in higher frequency circuits over normal varnish insulated magnet wire.
 

Tubetec

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Hi Terry ,
Cotton wrapped wire gives some extra grip between adjacent layers , as you could imagine plain enamel wire would slip all over the place . Its the wind patern that reduces the self capacitance of the coil although the extra spacing afforded by the cotton might have a small effect also . Universal coils are also dipped, the cotton absorbs some varnish which glues everything solidly together .
 

TerryG

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Sep 18, 2021
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Location
California USA
For some reason that wire looked like litz wire to me, I just assumed it was litz wire. Makes sense with cotton wrapped wire with the friction factor adding grip. I really need to get back in to Ham radio, back in high school my school had a ham shack with a club managing "air" time. It was fun for us high school students, made the world a much bigger place, and yet smaller as well
.
 
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