Search results
Results from the WOW.Com Content Network
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.
CBS used shortwave to support its Latin American international network, which consisted of 64 stations located in 18 countries and GE's KGEI opened in San Francisco in 1939, transmitting to Asia. [16] [17] [18] On November 1, 1942, all 14 private U.S. shortwave stations ended commercial operations and were leased to the Voice of America. [19]
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 ...
Curtain arrays were originally developed during the 1920s and 1930s when there was a lot of experimentation with long distance shortwave broadcasting. The underlying concept was to achieve improvements in gain and/or directionality over the simple dipole antenna, possibly by folding one or more dipoles into a smaller physical space, or to arrange multiple dipoles such that their radiation ...
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
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 ...
The 15-meter band (also called the 21-MHz band or 15 meters) is an amateur radio frequency band spanning the shortwave spectrum from 21 to 21.45 MHz. The band is suitable for amateur long-distance communications , and such use is permitted in nearly all countries.