[Amps] Real time tests to see if an RF transformer is saturating?

Chris Wilson chris at chriswilson.tv
Tue May 16 15:56:37 EDT 2017



Hello Manfred,


Yes, I understand the importance of each conductor being insulated and
woven  to  bring  stands in and out of the bundle, that's what I have
that's  so  hard to strip the enamel off. I only used the speaker wire
as  it  is  very  flexible,  pure  copper strands and of a large cross
section  for  current  handling. As you rightly warned, a 2mm or 2mm +
solid  enamelled  wire  is  not easy to wind tightly by hand with the
number of turns i built the second one with. I'd use the Litz for sure
if I could strip the damned stuff with recourse to spending hours with
paint  stripper.  i  tried  cellulose thinners, 2 other types of paint
remover,  very  strong  caustic  soda, everything I had that I thought
might work. The solder pot had no real effect on the enamel... :(


Thanks again!

On Tuesday, May 16, 2017,  you wrote:

> Chris,

>> I stacked 3 off 78 material cores in the same size as the 77 material
>> toroids and wound them with 180 strand speaker wire with a conductor
>> diameter of about 2mm.

> This sounds like you misunderstood one thing: That speaker wire surely
> has no insulation between the individual strands, and so it will behave
> exactly like a solid wire, in terms of RF performance. To achieve an 
> improvement over solid wire you need to have INSULATED strands! And 
> ideally they should be woven in a very specific way, so that each strand
> is on the surface and inside the bundle as much as any other strands. 
> The Litz wire suggested by Roger is exactly what you want, but it's 
> relatively rare and expensive. What's typically done is assembling a 
> bundle from many thin enameled wires, or winding with several enameled
> wires in parallel.

> Manfred







-- 
Best regards,
 Chris                            mailto:chris at chriswilson.tv



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