In article ,
Charly wrote:

Dear all,

I have, from an old bunch of computer wires in the disposal place of my
office,
some ferrite cores such as the ones described here :
http://www.tdk.com.tw/ctl_pdf/ctl_1.1.pdf

I have two with the following spec : ZCAT2032-0930

I can possibly use one on the feed line to the radio to reduce some noise,
but,
can this kind of material be used for building a balun/unun ? It is a tube of
ferrite instead of a toroid, so the windings might be a bit different...

Any hints out there ???

Thanks for your inputs,

Charly

Fig. 4 is your model. You will get 50 ohms impedance per turn at 10 MHz,
75 ohms at 20 MHz and 100 ohms at 30 MHz. Regressing the chart I
estimate 20 ohms at 5 MHz.

Two problems is BALUN/UNUN are a little more picky about the core and
these are two pieces. Better to have one piece core. Depending on the
type of impedance transformer you want to make this could be an OK value
of inductance for the frequencies you want it to operate on for a
voltage type but you would want more for a current type.

--
Telamon
Ventura, California