[TowerTalk] velocity factor for Saxton 8315 and 8316

[Jim Brown]

On Sat,11/8/2014 10:14 AM, Dick Green WC1M wrote:
> Thanks, Jim. Could you summarize the procedure (e.g., measure the cable open
> or shorted) and arithmetic for me?

k9yc.com/Coax-Stubs.pdf

Put a connector on one end, connect to the analyzer, leave the other end 
open, vary the frequency of the analyzer until you see a null (near zero 
ohms). That is a  quarter-wave, or some odd multiple of quarter waves.  
Or short the other end -- then the nulls will be at multiples of a half 
wave. Measure the physical length, compute wavelength at the test 
frequency, divide that by the free space wavelength and you've got Vf.

Example a free-space quarter wave on 80M is roughly 67 ft and is the 
lowest frequency null you measure, the length of the sample is 45 ft, so 
Vf is 45/67.

73, Jim K9YC