[Lowfer] Triflier Core Winding

[Frank Gentges KØBRA]

Peter,

I built two wideband transformers just the same except one was trifilar and 
the other was just 3 separate windings.  The one with separate windings 
went from 10 kHz to 10 MHz.  The trifilar one went from 10 kHz to 30 MHz.

I concluded that the trifilar, or bifilar for that matter, got the windings 
more closely coupled and reduced the leakage reactance between them and 
extended the top end of a wideband transformer about 1.5 times.

Frank K0BRA

At 09:01 AM 4/10/02 -0500, Peter Barick wrote:
>Loafers,
>
>I'm trying in vain to find information on the practice of "trifiler"
>winding, as used on a ferrite core.
>
>Why is it used? It seems to be a similar in style to Litz wire, the
>forming of a twisted 3-wire conductor and wrapping it on the core, where
>all like ends are tied together. This technique is new for me. I've seen
>it where the three comprised both input and output windings, however.
>
>I don't think it's to increase current cap., as the ref. I have is for
>receiving apps. Then could it be for flexibility for winging on a small
>core? Don't think that's it. Stumped.
>
>Does anyone know of a forum better able to answer this question?
>
>Peter
>
>
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Frank Gentges KØBRA
<fgentges@mindspring.com>
LF web site at <http://www.amrad.org/projects/lf>