Hi Mikek, Speed of Light = Frequency x Wavelength Therefore: Speed of Light/Frequency = Wavelength Speed of light = 299 792 458 m / s (I normally just use 300,000,000 m/s) Therefore: (300,000,000m/s) / (1190000 Hz) = 252.10 meters But this is a full wavelength, so you have to divide 252.10 meters/2 = 126.05 meters to calculate the length of a 1/2 wave dipole on 1190000 Hz.
But your dipole is not 126.05 meters long, it's 79.248 meters long. Therefore Velocity Factor is 79.248m/126.05m = 0.629 Hope this helps. 73, Don (wd8dsb) On Sat, May 2, 2020 at 4:58 PM Mikek <[email protected]> wrote: > I laid down 260ft of wire as a dipole on the ground, it is resonant at > 1190kHz. > I calculate this as a VF of 0.685, my calculation is actually 0.315 but > I don't think that's right, > so I subtracted from 1. Can someone post the proper formula to calculate > the VF using Resonant frequency and Length. > 260ft = 79.248 Meters Frequency is 1190kHz. > > Thanks, Mikek KF4ITA > _________________ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
