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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 ...
For transmissions in the shortwave range, there is little to be gained by raising the antenna more than a half to three quarters of a wavelength above ground level, and at lower frequencies and longer wavelengths, the height becomes infeasibly great (greater than 85 metres (279 ft)). Shortwave transmitters rarely use masts taller than about 100 ...
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).
Broadband shortwave base antennas traditionally fall into two main categories: Resistively loaded antennas which can be inexpensive and reasonably compact but inefficient at lower frequencies. Large elaborate and very expensive, non-loaded designs. (These can cost upward of $80,000 to purchase and install).
In telecom circles, any area with more than three antennas could be referred to as an antenna farm. In the case of an AM broadcasting station (mediumwave and longwave, occasionally shortwave), the multiple mast radiators may all be part of an antenna system for a single station, while for VHF and UHF the site may be under joint management.
Before the HRS antenna became the default design for high power broadcasting in the 1950s, Sterba curtains were used to transmit shortwave broadcasts. Sterba curtains are modest-gain single-band curtain array antennas. They are named after Ernest J. Sterba, who developed a simple shortwave curtain array for Bell Labs in the 1930s. [1]
A few examples of areal made of cage sections are: Shortwave quadrant antenna made of two horizontal cage sections. [1]Quadrant antenna A quadrant antenna is an omnidirectional shortwave transmitting antenna shaped like a rhombus or lozenge, made from two identical, opposing L-shaped cage dipoles ("L ⅂") lying in the same horizontal plane, aligned with their 'elbows' pointing in opposite ...
A 20-meter-long T²FD antenna, covering the 5-30 MHz band. The Tilted Terminated Folded Dipole (T²FD, T2FD, or TTFD) or Balanced Termination, Folded Dipole (BTFD) - also known as W3HH antenna - is a general-purpose shortwave antenna developed in the late 1940s by the United States Navy.