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

How about adapting (somehow or the other) computer monitor VGA cables
that already have a big ferrite core on each end of the cables to use
with radio antenna hookups? Only wondering.
cuhulin

wrote:
How about adapting (somehow or the other) computer monitor VGA cables
that already have a big ferrite core on each end of the cables to use
with radio antenna hookups? Only wondering.
cuhulin

Yes, I'll try to get some of these...

Thanks,

Charly

Well,my computer to computer monitor fifteen feet long VGA has a big
ferrite core on each end of the cable.I paid sixty dollars plus ten
dollars shipping & handling for my cable,I bought it from
www.si87.com in Bozeman,Montana about three years ago.The two ferrite
cores on the cable help to reduce/prevent ghosting images on my 22 inch
screen CRT Multisync computer monitor.Sure,I could have connected two
cheap cables together,but I wont go any cheapo route as regards my
computer equipment.My computer monitor sits on my coffee table and my
computer is about fourteen feet away on an end table by doggys
couch.Three big eyes (two tv sets and my computer monitor) staring back
at me.I dont know if a VGA computer cable will work for hooking up to a
radio though,I guess it's worth a try if it doesn't blow up the radio.I
wont be the one to try it first.
cuhulin

Telamon wrote:
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.


BIG THANKS !!!

This the kind of info I was looking for....

Charly