This antenna started all my experiments. See my Shack page for links to my Windom Fan Dipole early and recent setups.
Below is my dilemma. In the dual graphs the light line from the RigExpert scans are from the Shack end of the feed line to the balun. It is approximately
130 feet, RG-8X, from the Shack to the base of the antenna. From the base of the antenna to the balun is 47' or
about 50' of RG-8X. The darker line
is with the RigExpert connected to the down lead at the base of the antenna. All else constant it appears the 130'
from the antenna to the Shack "helps" the VSWR above 40 Meters ?????
And no, its not the cable. Above Time Domain Reflectometer scan
from the shack to the Balun. The small bump
just past 124 feet is the lightning arrester. I love the RigExpert!
Click on images below for a larger Graph
Scan 0 to 54 MHz. Note from the Shack the maximum VSWR values are
well below the ones at the antenna ???
Anyone have an idea why? 
Expanded view from 0 to 14.5 MHz
Focus on the 2 main resonance points. The OCF is a Fan Dipole with
a 1/2 wave 160M element and a 1/2 wave 80M element
45 degrees offset as in the photo of it at the top of this page.