Measurement Results 

I have measured the reflection with an Agilent network analyzer E5062A. I prefer the representation of the the S-parameters but I think not everybody really know what they are. Therefore I also published the SWR diagramm. There is a way to calculate the SWR from the s-params, but you should at least remember that -10dB is (almost) equal to VSWR of 2.

Agilent E5062E, 2-port network analyzer to 3GHz

yes, exactly...

...any questions? Just drop me a line via e-mail.

Here you can see the S11 in the range between 20MHz and 22MHz. The S11 is very low but has its minimum a lottle bit to low. The two marker show you where the 15m band is.
   

...for everybody who doesn't know anything about S11, here the SWR. You can use the antenna in the CW range without a tuner.