Cecil Moore wrote:
Roy Lewallen wrote:
The velocity factor of 300 ohm ribbon twinlead is approximately 0.80,
but it varies from brand to brand and lot to lot.

I measured the VF of 300 ohm and 450 ohm window-line from
The Wireman. The 300 ohm stuff was very close to 0.8 while
the 450 ohm was closer to 0.9

Incidentally, the Z0 of the "300 ohm" window-line
was considerably lower than 300 ohms and the Z0 of
the "440 ohm" window-line was about 388 ohms.
--
73, Cecil http://www.w5dxp.com