[TenTec] 75 Ohm twin velocity factor ?

Ed - K9EW k9ew57 at gmail.com
Fri Jan 26 15:56:10 EST 2007


> .....  does anyone know the typical velocity factor of commercial 75 Ohm twin feeder?

Hi Steve,

I don't think I've ever heard of 75 ohm twinlead.

I looked up 450 ohm twinlead on www.thewireman.com, and the vf is
0.91.  For 300 ohm twinlead, it's 0.66 for solid dielectric, and 0.91
for windowed dielectric.  A couple of years ago I measured some 300
ohm twinlead (solid dielectric) that I had, using an MFJ-259B, and the
vf was around 0.7.  If you're using 300 ohm solid dielectric twinlead,
it would be best to measure the actual vf, or to get the spec from the
manufacturer.

73,
ed - k9ew


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