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A less ambitious idea of “broadband antenna” (often called “wideband”) is an antenna that continuously covers the proportionally widest amateur band, that spans 3.5–4.0 MHz (a 14% bandwidth), [b] without requiring an antenna tuner. There are many such designs, but those are not discussed here.
Hexbeam amateur radio antenna. A hexbeam, or hexagonal-beam, is a type of a directional antenna for shortwave, most often used in amateur radio. The name comes from the hexagonal outer shape of the antenna. It may also sometimes be known as a W-antenna, referring to the shape of the driver. The design looks something like an upturned umbrella.
Shortwave broadcasting in the United States allows private ownership of commercial and non-commercial shortwave stations that are not relays of existing AM/MW or FM radio stations, as are common in Africa, Europe, Asia, Oceania except Australia and Latin America. In addition to private broadcasters, the United States also has government ...
Modern shortwave radio receivers are relatively inexpensive and easily accessible, and many hobbyists use portable "world band" receivers and built-in telescopic antennas. Serious hobbyists may use expensive (shortwave) communications receivers and outdoor antenna located away from electrical noise sources, such as a dipole made from wire and ...
The ALLISS module is a fully rotatable antenna system for high power (typically 500 kW only) shortwave radio broadcasting—it essentially is a self contained shortwave relay station. Most of the world's shortwave relay stations do not use this technology, due to its cost (15m EUR per ALLISS module: Transmitter + Antenna + Automation equipment).
ALLISS allows a broadcaster to change the following shortwave transmission parameters at any time: direction (azimuths from 0 to 360 degrees, rate: ~1 deg / 6 sec), broadcast frequency, and antenna configuration (i.e.: HR 4/4/1 -> HR 6/4/1). All of these transmission mode changes can take effect in as little as 5 minutes.
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Shortwave bands are frequency allocations for use within the shortwave radio spectrum (the upper medium frequency [MF] band and all of the high frequency [HF] band). Radio waves in these frequency ranges can be used for very long distance (transcontinental) communication because they can reflect off layers of charged particles in the ionosphere and return to Earth beyond the horizon, a ...