[Lowfer] Triflier Core Winding

[John Andrews]

Peter,

Do a Google search on "trifilar winding" (note spelling of trifilar), and
you'll get all sorts of references.

Bifilar (2 twisted wires), trifilar (3) and quadrifilar (4) transformers
provide low-loss broadband impedance transformation. The impedance ratio is
the square of the number of turns in the winding. So you get 4:1 for
bifilar, 9:1 for trifilar, etc.

These are called "transmission line transformers," and generally have lower
loss and wider bandwidths than conventional primary/secondary transformers.
They do have higher capacitance between input and output, which might be a
problem in some applications.

John Andrews, W1TAG


> I'm trying in vain to find information on the practice of "trifiler"
> winding, as used on a ferrite core.