Stripping Litzendraht

Stripping Litzendraht

Post by Han » Wed, 20 Feb 2013 09:11:08



Going back to the year 1956, I designed a high-Q IF 1600 Kc IF
transformer to put in the Millen product line.  To get the desired Q I
ended up using Litzendraht---something like 30 (strands of) #48.  

You'll need to use a chemical *** on stuff like this.  Mechanical
stripping will work-harden the wire ends, and they'll break.  The
effect on Q with one broken strand is astounding---as I recall, it
would cut it by about half.  

What we used in production was commercial aircraft paint-***.
That's vicious stuff.  GC sold small bottles of this as chemical wire
***.  After soldering, you'll need to wash the terminations with
isopropyl ***.  

Some years later, when rebuilding an RME-45 receiver, I took out all
the coils, including the IF's.  Those used Litzendraht, and a Q-meter
inspection showed incredibly low Q.  I had to disconnect the coil
leads, restrip, and resolder, which brought Q back up.  

Hank

 
 
 

Stripping Litzendraht

Post by Joe Bent » Wed, 20 Feb 2013 09:52:43



Quote:
> Going back to the year 1956, I designed a high-Q IF 1600 Kc IF
> transformer to put in the Millen product line.  To get the desired Q I
> ended up using Litzendraht---something like 30 (strands of) #48.

> You'll need to use a chemical *** on stuff like this.  Mechanical
> stripping will work-harden the wire ends, and they'll break.  The
> effect on Q with one broken strand is astounding---as I recall, it
> would cut it by about half.

> What we used in production was commercial aircraft paint-***.
> That's vicious stuff.  GC sold small bottles of this as chemical wire
> ***.  After soldering, you'll need to wash the terminations with
> isopropyl ***.

> Some years later, when rebuilding an RME-45 receiver, I took out all
> the coils, including the IF's.  Those used Litzendraht, and a Q-meter
> inspection showed incredibly low Q.  I had to disconnect the coil
> leads, restrip, and resolder, which brought Q back up.

> Hank

Many of the BCB crystal set DX'rs use litz on the order of 600/44 for
their coils.  This stuff sells on the order of $2.00 a foot or more, and
is about the same gauge as #10 or #12 copper. From what I recall from
past conversations with some of these guys, the enamel used on those 600
strands of wire will dissolve nicely by simply dipping the end in a
solder pot. The nylon serving is manually stripped back.

Joe, N6DGY

 
 
 

Stripping Litzendraht

Post by Foxs Mercantil » Wed, 20 Feb 2013 12:27:23



Quote:
>  From what I recall from past conversations with some of these guys, the
> enamel used on those 600 strands of wire will dissolve nicely by simply
> dipping the end in a solder pot.

IF and ONLY if the manufacturer used wire coated with "Stripeze"
insulation. Typically, it's either a Red or Green coating. The
solder pots have to be cranked up a bit closer to 800F instead of
650-700F for the coating to properly come off. Make sure you dip
it in RMA rosin flux first.

On the other hand, it you've got wire that's that brownish color,
that's real enamel and the purplish/brown stuff is Formvar. Both
are a real pain in the rear to remove. Formvar is worse though.

Jeff-1.0
wa6fwi

 
 
 

Stripping Litzendraht

Post by Adrian Tuddenh » Wed, 20 Feb 2013 17:59:03


Quote:

> Going back to the year 1956, I designed a high-Q IF 1600 Kc IF
> transformer to put in the Millen product line.  To get the desired Q I
> ended up using Litzendraht---something like 30 (strands of) #48.  

> You'll need to use a chemical *** on stuff like this.  

When I worked for a radio manufacturer in the late 1960s we used a
thermal/chemical system based on a methylated spirits burner.  The wire
ends were held in the spirits flame until they were red hot, and then
plunged into the *** at the base of the flame.  The hot copper oxide
was reduced to pure copper by the *** and the result was a very
solderable annealed copper surface with no mechanical damage.

There were certain insurance issues over the use of this burner;
especially when I equipped it with an ignition system which flicked a
sparay of the *** through an inductive spark - then offered to light
the chief engineer's cigarette with it.

--
~ Adrian Tuddenham ~
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www.poppyrecords.co.uk