The mean lifetime of my simple wire antennas is relatively short, and my folded weirdly antenna for the 40m band was no exception.
http://spinorlab.wordpress.com/2013/09/19/folded-weirdly/
Last weekend I re-installed the element with supposedly almost the same configuration, but this time with each leg of the element to be 10m long.
With the usual measurement it is observed that at 7026kHz CH1=2.943V, CH2=2.638V, and CH2-delay=+12.60nS.
gnuplot> load "gnuplot.txt"
Freq [MHz]=7.026
V1=2.943
V2=2.638
Cursor 1=1.26e-08
Cursor 2=0.0
vratio=0.896364254162419
phase1 [deg]=31.869936
phase2 [deg]=0.0
abs(gamma)=0.530090794923996
swr=3.25614135325678
cz={20.4433917939881, 26.9131366419314}
With a Smith chart and a physical cable length of 20m (remember the velocity factor of 0.66), you start from a red point (Zdut=20.443+j26.913), rotate towards load (not towards generator!), and end with a green point (Zant=27.182-j40.050), which shows the radiation impedance of the antenna.
