Monthly Archives: July 2013

The drivel written about antennas

Typical NVIS Far Field PlotI check into the HamAntennas Yahoo Group fairly often and it occurs to me that collectively, there seems to be a lot of smoke and mirrorsĀ surrounding the design of low-band antennas and everyone seems to forget the basic principles, that low-to-the-ground antennas will form bubbles of RF above you. We call them NVIS or Cloud Burner antennas. The graphic is a plot of my home-brew 40m loop in the garden from MMANA. It’s 25 feet above the groundĀ (which is exactly the same far-field plot as an 80m loop at 50 feet). Clearly it’s going to work well at what it’s designed for. Up to about 1,500 miles. In practice, it conforms precisely to my software plot.

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