NVIS Simplified
Shortwave Antennas that are simple, cheap and good for local Comms when LOS (Line of Sight) communications are not possible and the intended receiver is too close to use "Skip"
NVIS (Near Vertical Incidence Skywave) antennas were developed by Germany in WWII on the Eastern Front. It's a way of deliberately limiting the range of your transmitter to a few hundred miles. The Germans found that effective communication could be achieved with the antenna only a few feet off the ground. For example, the hoop-like structure above this command car is an NVIS antenna.
Constructed horizontally using plain old wire (what they use for house wiring works fine), these antennas work very close to the ground and can be easily raised or lowered depending on what frequency you are using. In an emergency, you could just lay the antenna wire on the ground and get some good range out of it.
They work by directing all the power as close to straight up as possible so it will bounce off the ionosphere. Think of a spotlight shining straight up and reflecting off of clouds. You could read by the reflected light for several miles around the spotlight.
They interest me because I could actually install one of these where I live at low cost and avoid having to invest in a tower. Once you're on the air, you can do all kinds of neat stuff like BBS-style email using the old store-and-forward method we used to use with modems.
Now that a cheap antenna solution has presented itself, I have incentive to go ahead and finish getting my Ham ticket.
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