Topband: Propagation and evaluation of antennas...

[Lars Harlin]

Hi all!
Not much on the band this morning so better be on the keyboard...
Regarding propagation on this band its an interesting issue. Have found many times that even if the A- and K-index is at low values, like this morning, still there is no propagation. My experience, living at 63 deg north,is that the solar wind data is a far better indicator. This morning both the A- and K-index = 0, but with high solar wind velocity and density levels. And the band is quiet. Have also seen the opposite many times this season, So without knowing exactly how they relate, thats my reflection. 

Agree that its hard to compare different antennas if you dont have a reference antenna to compare to. Its then more like a gut feeling that one can get after beeing on the band for a while, in different propagation, different times and how well one compete in pile ups. Myself I've been testing a new antenna idea here for a couple of weeks, unfortunally without a reference antenna but by now, with a good gut feeling. This antenna needs no radials, yet it has about the same vertical far field diagram as a quarter wave vertical antenna. You can easiest describe the antenna as a half square that has been stretched out into an inv vee configuration with its apex at 17 meters. Total length is 158 m and the feedpoint is 25% (abt 40m ) from one of the ends. It has a comfortable feedpoint impedance for direct coax feed. Have a model in Eznec of the antenna if anyone out there is interested. Will do more evaluating, but so far the results are very satisfying.

73 de Lars, SM3BDZ