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From: Alan G3NOQ
Date: 18 Jun 2003
Time: 11:00:10
Remote Name: 20.138.254.2
Johan - It is a recognised propagation method and is definitely not a tale. It uses high-angle reflection from the lowest layer, to fill in the skip distance. . . Usually, there is a minimum angle of incidence at which reflection occurs. If you imagine looking up from under water, at high angles of incidence there is no reflection and you can see out of the water. But, with radio waves, if you reduce the frequency enough, the layer reflects even at vertical incidence, and that's NVIS. You need antennas with a lot of high-angle pattern and it's often done by bending a whip antenna over so it's nearly horizontal . . . 73s, Alan