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Re: E55 Ferrite transformer and Litz wire

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On 6.2.17 14:43, Chris Jones wrote:
> On 05/02/2017 01:47, Tim Williams wrote:
>> "Winfield Hill" <hill@rowland.harvard.edu> wrote in message
>> news:o73ai1012r6@drn.newsguy.com...
>>> I often use large-diameter litz with hundreds of tiny
>>> wires.  I follow my technician's approach, which is to
>>> use a solder pot.  I dip the litz bundle into a gross-
>>> looking paste flux and then into the pot.  Voila, an
>>> instant ready-to-go solder-encrusted termination.
>>
>> "Large"?  That's cute. ;-)
>>
>> In the induction heating business, inch-wide rope is regularly used.
>> The ends are crimped into several-aught size lugs, some rosin dripped
>> in, then dipped whole into a solder pot.  When the bubbling subsides,
>> it's ready.
>>
>> On a less bragging matter:
>>
>> I've made litz myself, using whatever stuff I have laying around.  On
>> several occasions, I've made the mistake of using this old brown stuff
>> that's classic "enamel".  It just carbonizes harder and harder, on
>> heating!
>>
>> So I get out an abused teablepoon, and melt a lump of potassium
>> chlorate(!) in it.  Heat the wire briefly in the flame, then dip the
>> wire in the salt: FOOF, no more enamel!  Water quenches and dissolves
>> the salt stuck in the wire, leaving perfectly clean, pink copper, ready
>> to be tinned!
>
> You can also do it by heating the wire to red heat and then rapidly
> plunging it into alcohol (ethanol, methylated spirits etc.) whilst still
> red hot. If the wire has insufficient heat capacity to stay red hot long
> enough to do the above, then you can wrap it with some other copper wire
> just to increase the thermal mass. The added wire may get welded to the
> Litz wire if you heat it too much. That may or may not be a problem.
>
> Obviously, messing with blowtorches around a pot of alcohol is likely to
> result in a fire, so do it in a place where a fire won't be a problem,
> and limit the quantity of alcohol to the amount that would not cause a
> problem if it catches fire.


I did it without blowtorches by putting a wad of cotton in a
metal can lid, pouring some denaturated alcohol into it and
firing it up. The Litz was put into the flame and then pressed
to the wet wad and pulled out sideways. This worked fine for
the wire in IF transformers in the tube era.

The alcohol does not need to denaturated, but due to the alcohol
policies in the Nordic countries it was the only resonable. The
connoisseurs could flamber it with Courvoiser.

-- 

-TV

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Re: E55 Ferrite transformer and Litz wire albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2017-02-03 19:54 +0100
  Re: E55 Ferrite transformer and Litz wire jrwalliker@gmail.com - 2017-02-03 15:06 -0800
    Re: E55 Ferrite transformer and Litz wire Winfield Hill <hill@rowland.harvard.edu> - 2017-02-03 17:25 -0800
      Re: E55 Ferrite transformer and Litz wire "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-02-04 08:47 -0600
        Re: E55 Ferrite transformer and Litz wire Chris Jones <lugnut808@spam.yahoo.com> - 2017-02-06 23:43 +1100
          Re: E55 Ferrite transformer and Litz wire "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-02-06 08:17 -0600
          Re: E55 Ferrite transformer and Litz wire Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2017-02-06 20:11 +0200
  Re: E55 Ferrite transformer and Litz wire Okkim Atnarivik <mikkivir@gmail.com> - 2017-02-06 06:12 -0800

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