Class of large multielement directional wire radio transmitting antennas
Curtain arrays at Radio Free Europe transmitter site, Biblis, GermanyCurtain array at international shortwave broadcasting station, Moosbrunn, Austria. It consists of 4 columns of horizontal wire dipoles, suspended in front of a wire screen. The vertical parallel wire feedlines to each column of dipoles are visible. The entire antenna is mounted on a rotating truss structure, allowing it to be pointed in different directions.
Curtain arrays, a class of large multielement directional radio transmitting wire antennas, are used in the short-wave radio bands.[1] They constitute a type of reflective array antenna, consisting of multiple wire dipole antennas, suspended in a vertical plane, often positioned in front of a "curtain" reflector made of a flat vertical screen of many long parallel wires.[1] These are suspended by support wires strung between pairs of tall steel towers, reaching heights of up to 90 m (300 feet) high.[1] primarily employed for long-distance skywave (or skip) transmission, they emit a beam of radio waves at a shallow angle into the sky just above the horizon, which is then reflected by the ionosphere back to Earth beyond the horizon. Curtain arrays find extensive use among international short-wave radio stations for broadcasting to large areas at transcontinental distances.[1]
Due to their powerful directional characteristics, curtain arrays are frequently utilized by government propaganda radio stations to beam propaganda broadcasts across national borders into other nations. For instance, curtain arrays were used by Radio Free Europe and Radio Liberty to broadcast into Eastern Europe.
^ abcdGriffith, B. Whitfield (2000). Radio-electronic Transmission Fundamentals, 2nd Ed. SciTech Publishing. p. 477. ISBN 1884932134.
Curtainarrays, a class of large multielement directional radio transmitting wire antennas, are used in the short-wave radio bands. They constitute a type...
PAVE PAWS phased array antenna, left Batwing VHF television broadcasting antenna Crossed-dipole FM radio broadcast antenna Curtainarray shortwave transmitting...
Other names are bedspring array and bowtie array depending on the type of elements making up the antenna. The curtainarray is a larger version used by...
screen, or curtain, or curved dish. Usually only one of the component antennas is resonant on the design frequency. The two subtypes of array and aperture...
modest-gain single-band curtainarray antennas. They are named after Ernest J. Sterba, who developed a simple shortwave curtainarray for Bell Labs in the...
typical antennas consist of a dipole about 1 /4 wavelength above ground, or arrays of such dipoles. Up to 16 dipoles can be used, allowing strong signals with...
Moxon rectangle is a simple and mechanically rugged two-element parasitic array, single-frequency antenna. It takes its name from the amateur radio operator...
Franklin went on to refine the directional transmission by inventing the curtainarray aerial system. In July 1924, Marconi entered into contracts with the...
and curtainarrays. Larger log periodics provide wider frequency coverage with comparable gain to rhombics. Distributed feed curtains or HRS curtain arrays...
antennas. Powerful shortwave broadcasting stations often use large wire curtainarrays. Antennas for transmitting skywaves are typically made from horizontal...
a roundabout a few hundred metres from the original site. Rotatable curtainarray antennas were not in common use until the 1960s, so PCJ was far ahead...
ended. A portion of the large RCI shortwave antenna system (known as a curtainarray) is visible in the background. The antennas were removed in 2014, although...
cables leading out to a large "aerial field" where masts carried a complex array of antennas for transmitting multiple radio programmes simultaneously to...
before HRS 12/6/1 technology became available in the west. HRS 8/8/1 curtainarrays create a 10-degree beam of shortwave energy, and can provide a highly...
passive reflector wire, spaced 0.18 wavelength back. The resulting curtainarray antenna produced a horizontally polarised signal that was directed strongly...
transmitter and a 30-year-old RCA transmitter all feeding several stacked curtainarrays which are beamed on South East Asia. They operate mainly on the 9 and...
Former RFI Issoudun Relay station feeders and curtainarrays Former RFI Issoudun Relay curtainarrays (1990s) The International broadcasting center of...
complete new installation. Ten 500 kW transmitters and 34 wideband curtainarrays were installed. The majority of antennas point in an Easterly direction...
decommissioned, the VLQ9 and VLM4 services were discontinued and the shortwave curtainarray antennas removed. The original VLQ transmitter is completely preserved...
shortwave antennas for international broadcasting are the HRS antenna (curtainarray), which covers a 2:1 frequency range, and the log-periodic antenna,...
Former RFI Issoudun Relay station feeders and curtainarrays Former RFI Issoudun Relay curtainarrays The International broadcasting center of TDF (Télédiffusion...
Former RFI Issoudun Relay station feeders and curtainarrays Former RFI Issoudun Relay curtainarrays The International broadcasting center of TDF (Télédiffusion...
A light curtain is a safety device that detects when a beam of infrared light has been broken by a person passing through an area. Light curtains, now...
broadcasts used a series of shorter free-standing masts supporting curtainarrays.[citation needed] Under the right conditions, the AM signal for National...
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