Message	Date	From	Subject
1583	2008-04-22 19:49:31	VE4KEH	Wire-Wrap Wire and Toroids (was help my junk box)
I recall reading somewhere (though I can't remember where) that two pieces of 30 gauge wire-wrap wire twisted 6 to 8 turns per inch had a characteristic impedance of around 50 ohms. I don't know if it comes in different insulating materials (I think the stuff I have uses "kynar", if my memory & spelling is correct), but that may influence the impedance a bit. I imagine some 50 ohm wire-wrap transmission line and a small toroid would make an excellent QRP choke balun. More information on using twisted wire as transmission lines can be found in an article called Twisted Magnet Wire Transmission Line by Peter Lefferson. It's from an IEEE publication, but I found my copy somewhere on the Web. Kent VE4KEH

I recall reading somewhere (though I can't remember where) that two
pieces of 30 gauge wire-wrap wire twisted 6 to 8 turns per inch had a
characteristic impedance of around 50 ohms. I don't know if it comes in
different insulating materials (I think the stuff I have uses "kynar",
if my memory & spelling is correct), but that may influence the
impedance a bit.

I imagine some 50 ohm wire-wrap transmission line and a small toroid
would make an excellent QRP choke balun.

More information on using twisted wire as transmission lines can be
found in an article called Twisted Magnet Wire Transmission Line by
Peter Lefferson. It's from an IEEE publication, but I found my copy
somewhere on the Web.

Kent VE4KEH