Owen Duffy wrote:
Wireman's data for #561 and #562 shows vf=0.91, and for #563, vf=0.66.

I have found wide variation in line construction and hence vf of
nominally 300 ohm line, and suggest that it is worth measuring.

I use #562 on my 20m rotatable dipole. Its VF measures
very close to 0.8. I needed the accuracy because I
vary the length of the feedline in order to resonate
the system on 20m-6m.
--
73, Cecil http://www.w5dxp.com