[TowerTalk] Winding A New Linear Loading Coil for a Cushcraft 402-CD

[Jim Lux]

On 10/26/11 5:28 PM, Charlie Gallo wrote:
>
> On 10/26/2011 Bill Jackson wrote:
>
>> My question is directed to those of you who build your own antennas.  Is there
>> any technique or home brew aide(s) that will assist in getting this coil wound
>> tightly with no spacing between the turns?  I seem to recall seeing an article
>> many moons ago that talked about using a paint stirring stick with a hole
>> drilled in the end to hold the wire while you wind it around the core.  #12 AWG
>> is pretty stiff for a 3/4" form and I want to make it look as good as the
>> factory original.
>
> A place I worked did a LOT of toroidal core winding.  One of the ways of keeping the wire neat was they had a spring loaded clamp, that was lined with what was basically a rough, deep synthetic velvet like pad - soft enough NOT to scratch the wire being pulled through, it - it was firmly attached to the machine, and the wire was drawn through it, effectively keeping tension on the wire, as the form was turned (we also did straight forms, I cores etc, not just torroids (which require a special machine, kinda nifty)
>
> One nifty way of guiding the wire once you make the clamp is with a lathe - put the form "between centers", and run the lathe slowly, with the proper feed on the carriage, and it advances the wire for you
>

I've wound coils on a lathe (I used to build Tesla coils, and putting 
1000 turns on a coil is pretty tedious by hand.)  The challenge is that 
once you engage the clutch on the lathe, you have to keep up and pray 
that the spool doesn't have a dent or the wire tangle. Shades of Lucy 
and the chocolate boxes.


The last few times: foot switch and a small motor.  A variable speed 
drill also works pretty well.  I also did one with a foot pedal 
(variable resistor type) to a variable speed motor drive feeding the the 
lathe. That was great.

If you need lots of turns....
Put the spool of wire on the floor on it's side
bring the wire up to where you're winding
Put a funnel over the wire, open end down (towards the spool), so that 
it sits on the rim of the spool.

A leather glove or piece of chamois cloth to hold the wire, and off you go.


I've never tried this with anything bigger than about AWG16.  For AWG 12 
or 10 or bigger, I've wound it by hand, because it's usually not that 
many turns, and it's faster just to wind by hand than set up the jig or 
motor.