Triband Delta Loop antenna – some theory

Looking for an improvement in my station’s configuration, I evaluated a number of antenna designs; the most important thing, wether some like to admit it or not, is what possibilities you have for installation. What type of ground, how high can you put it, is the surrounding space opened enough towards the horizon, are there elevated points you can use for support, what kind of weather it will have to endure, how can you properly make the safety grounding etc. All these factors are very important in the choice of an antenna, and i’ll come up with a quick example: a ground mounted L/4 vertical above salt water (let’s say, on the beach of a small oceanic island) for the 40m band will put out a DX signal similar to an horizontal dipole mounted at about 30m high (horizontal antennas need height to obtain better gain at lower takeoff angles), and the dipole will need to be rotated towards the direction you want to work while the vertical is omnidirectional. If you look at the costs of building a 30m tall tower, adding a rotator to it and the mechanical challenge of making it stable in saltwater-impregnated sand versus the costs of a few wires and a 20m tall lightweight fiberglass pole, the choice is a no-brainer. However, move the same setup above a poor, dry ground (let’s say,...

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