Following on from the antenna modelling I did a with EZNEC a few months back I am now building the antenna and planning the ground system. I want to do some measurements of the antenna (approx 48ft v
Dave, One rule of thumb for the distance considered to be in the "far field" is roughly 10 times the height of the vertical, or the spacing of verticals in an array. At this distance, there is essent
I recall reading somewhere that you should be at least 10 wavelengths distant from the antenna. This is to ensure you are out of the near field when taking the measurement. I've always wondered howe
Ultimately, the far field is where it is impossible to distinguish the radiation due to distribution of current along the antenna from that of a point source. This can be quite different for various
I also recall near-field/far-field expressed in terms of wavelengths. But I believe it depends on both wavelengths and antenna size. So, it seems appropriate to recommend the larger of (say) 10 time
What I have never seen documented is actual measurements of far-field sky-wave changing with numbers of radials, along with the corresponding measurements at the ground. Sky-wave has always been by i
I haven't done any serious antenna design work in 25 years or so, but the rule of thumb I remember using was 2d^2/wavelength, where d was the largest dimension of the antenna. While not an abrupt tra
-- Although it's on loan to a friend now, The Collins Radio "Fundamentals of Single Side Band" book has exactly that. I seem to remember mine was a second edition published in 1952. It has all sorts
Guy, Actually, the regulatory bodies are very interested in skywave propagation -- it is the basis for nighttime interference protection among AM broadcast stations. But you are correct that skywave
Well, good. Any idea where I might be able to dig up that document? Or where to start? I remember listening to WHO in Columbus, Ohio as an eleven-year old with a 5 tube radio after everyone else asle