Micron Document
`:top
`!Curtain arrays`! are a class of large multielement `F33f`_`[directional`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Directional_antenna]`_`f radio transmitting wire `F33f`_`[antennas`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Antenna_(radio)]`_`f, used in the `F33f`_`[short-wave`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Shortwave]`_`f radio bands.`:cite-ref-griffith-1-0[`F5bf`_`[1`#cite-note-griffith-1]`_`f] They constitute a type of `F33f`_`[reflective array antenna`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Reflective_array_antenna]`_`f, consisting of multiple wire `F33f`_`[dipole antennas`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Dipole_antenna]`_`f, suspended in a vertical plane, often positioned in front of a "curtain" reflector made of a flat vertical screen of many long parallel wires.`:cite-ref-griffith-1-1[`F5bf`_`[1`#cite-note-griffith-1]`_`f] These are suspended by support wires strung between pairs of tall steel towers, reaching heights of up to 90 m (300 feet) high.`:cite-ref-griffith-1-2[`F5bf`_`[1`#cite-note-griffith-1]`_`f] Primarily employed for long-distance `F33f`_`[skywave`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Skywave]`_`f (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 `F33f`_`[ionosphere`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Ionosphere]`_`f back to Earth beyond the horizon. Curtain arrays are extensively used by international short-wave `F33f`_`[radio stations`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Radio_station]`_`f for broadcasting to large areas at transcontinental distances.`:cite-ref-griffith-1-3[`F5bf`_`[1`#cite-note-griffith-1]`_`f]

Due to their powerful directional characteristics, curtain arrays are frequently utilized by government propaganda radio stations to beam `F33f`_`[propaganda`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Propaganda]`_`f broadcasts across national borders into other nations. For instance, curtain arrays were used by `F33f`_`[Radio Free Europe`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Radio_Free_Europe/Radio_Liberty]`_`f and `F33f`_`[Radio Liberty`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Radio_Free_Europe/Radio_Liberty]`_`f to broadcast into `F33f`_`[Eastern Europe`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Eastern_Europe]`_`f.

>>Contents

• `F0af`_`[History`#history]`_`f
• `F0af`_`[Description`#description]`_`f
• `F0af`_`[Three-array systems`#three-array-systems]`_`f
• `F0af`_`[Nomenclature`#nomenclature]`_`f
• `F0af`_`[HRS antenna`#hrs-antenna]`_`f
• `F0af`_`[HRS description`#hrs-description]`_`f
• `F0af`_`[Steering`#steering]`_`f
• `F0af`_`[Azimuth beamwidth`#azimuth-beamwidth]`_`f
• `F0af`_`[Vertical launch angle`#vertical-launch-angle]`_`f
• `F0af`_`[Examples of HRS antennas`#examples-of-hrs-antennas]`_`f
• `F0af`_`[Shortwave relay stations using only HRS antennas`#shortwave-relay-stations-using-only-hrs-antennas]`_`f
• `F0af`_`[Active sites`#active-sites]`_`f
• `F0af`_`[Decommissioned sites`#decommissioned-sites]`_`f
• `F0af`_`[RADAR Systems using HR Type Antennas`#radar-systems-using-hr-type-antennas]`_`f
• `F0af`_`[References`#references]`_`f
• `F0af`_`[External links`#external-links]`_`f

-─

>>History

Curtain arrays were originally developed during the 1920s and 1930s when there was a lot of experimentation with long distance `F33f`_`[shortwave`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Shortwave]`_`f broadcasting. The underlying concept was to achieve improvements in gain and/or directionality over the simple `F33f`_`[dipole antenna`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Dipole_antenna]`_`f, possibly by folding one or more dipoles into a smaller physical space, or to arrange multiple dipoles such that their radiation patterns reinforce each other, thus concentrating more signal into a given target area.

In the early 1920s, `F33f`_`[Guglielmo Marconi`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Guglielmo_Marconi]`_`f, pioneer of radio, commissioned his assistant `F33f`_`[Charles Samuel Franklin`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Charles_Samuel_Franklin]`_`f to carry out a large scale study into the transmission characteristics of short wavelength radio waves and to determine their suitability for long-distance transmissions. Franklin invented the first curtain array aerial system in 1924, known as the 'Franklin' or 'English' system.`:cite-ref-bray-2-0[`F5bf`_`[2`#cite-note-bray-2]`_`f]`:cite-ref-3[`F5bf`_`[3`#cite-note-3]`_`f]

Other early curtain arrays included the Bruce array patented by `F33f`_`[Edmond Bruce`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Edmond_Bruce]`_`f in 1927,`:cite-ref-4[`F5bf`_`[4`#cite-note-4]`_`f] and the `F33f`_`[Sterba curtain`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Sterba_antenna]`_`f, patented by Ernest J. Sterba in 1929.`:cite-ref-sterba-5-0[`F5bf`_`[5`#cite-note-sterba-5]`_`f] The Bruce array produces a vertically polarised signal; Sterba arrays (and the later HRS antennas) produce a horizontally-polarised signal.

The Sterba curtain was the first curtain antenna to achieve wide use, it was used by `F33f`_`[Bell Telephone`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Bell_Telephone_Company]`_`f and other telephone companies during the 1930s and 1940s for transoceanic telephone connections. However it is a narrowband design and is only steerable by mechanical means.

Curtain arrays were used in some of the first `F33f`_`[radar`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Radar]`_`f systems, such as Britain's `F33f`_`[Chain Home`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Chain_Home]`_`f network. During the `F33f`_`[Cold War`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Cold_War]`_`f, large curtain arrays were used by the `F33f`_`[Voice of America`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Voice_of_America]`_`f, `F33f`_`[Radio Free Europe`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Radio_Free_Europe]`_`f, and `F33f`_`[Radio Liberty`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Radio_Liberty]`_`f, and analogous Western European organizations, to beam propaganda broadcasts into communist countries, which censored Western media.

>>Description

The `F33f`_`[driven elements`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Driven_element]`_`f are usually `F33f`_`[half-wave dipoles`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Dipole_antenna]`_`f, fed in phase, mounted in a plane ⁠ 1 / 4 ⁠ `F33f`_`[wavelength`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Wavelength]`_`f in front of the reflector plane. The reflector wires are oriented parallel to the dipoles. The dipoles may be vertical, radiating in `F33f`_`[vertical polarization`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Vertical_polarization]`_`f, but are most often horizontal, because `F33f`_`[horizontally polarized`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Horizontal_polarization]`_`f waves are less absorbed by earth reflections. The lowest row of dipoles are mounted more than ⁠ 1 / 2 ⁠ wavelength above the ground, to prevent ground reflections from interfering with the radiation pattern. This allows most of the radiation to be concentrated in a narrow `F33f`_`[main lobe`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Main_lobe]`_`f aimed a few degrees above the horizon, which is ideal for `F33f`_`[skywave`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Skywave]`_`f transmission. A curtain array may have a `F33f`_`[gain`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Antenna_gain]`_`f of 20 `F33f`_`[dB`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Decibel]`_`f greater than a simple dipole antenna.`:cite-ref-griffith-1-4[`F5bf`_`[1`#cite-note-griffith-1]`_`f] Because of the strict phase requirements, earlier curtain arrays had a narrow bandwidth, but modern curtain arrays can be built to cover up to a 2:1 frequency ratio, allowing them to cover several shortwave bands.`:cite-ref-griffith-1-5[`F5bf`_`[1`#cite-note-griffith-1]`_`f]`:cite-ref-6[`F5bf`_`[6`#cite-note-6]`_`f]

Rather than feeding each dipole at its center, which requires a "tree" transmission line structure with complicated `F33f`_`[impedance matching`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Impedance_matching]`_`f, multiple dipoles are often connected in series to make an elaborate `F33f`_`[folded dipole`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Folded_dipole]`_`f structure which can be fed at a single point.

In order to allow the beam to be steered, sometimes the entire array is suspended by cantilever arms from a single large tower which can be rotated. See `F33f`_`[ALLISS-Antenna`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=ALLISS]`_`f. Alternatively, some modern versions are constructed as `F33f`_`[phased arrays`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Phased_array]`_`f in which the beam can be slewed electronically, without moving the antenna. Each dipole or group of dipoles is fed through an electronically adjustable `F33f`_`[phase shifter`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Phase_shifter]`_`f, implemented either by passive networks of capacitors and inductors which can be switched in and out, or by separate output RF `F33f`_`[amplifiers`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Amplifier]`_`f. Adding a constant `F33f`_`[phase shift`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Phase_shift]`_`f between adjacent horizontal dipoles allows the direction of the beam to be slewed in `F33f`_`[azimuth`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Azimuth]`_`f up to ±30° without losing its radiation pattern.`:cite-ref-itu-rec-7-0[`F5bf`_`[7`#cite-note-itu-rec-7]`_`f]

>>>Three-array systems

Transmission system are optimized for geopolitical reasons. Geopolitical necessity leads some international broadcasters to occasionally use three separate antenna arrays: highband and midband, as well as lowband HRS curtains.

Using three curtain arrays to cover the HF broadcasting spectrum creates a highly optimized HF transmission system, but three or more curtain arrays can be costly to build and maintain, and no new HF relay stations have been built since the mid-1990s. The modern HRS antenna design has a long lifespan, however, so existing HRS shortwave transmission systems built before 1992 will likely remain available for some time.

>>Nomenclature

Since 1984 the `F33f`_`[CCIR`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=ITU-R]`_`f has created a standardised nomenclature for describing curtain antennas, CCIR HF Transmitting Antennas consisting of 1 to 4 letters followed by three numbers:

`!First letter`!
Indicates the orientation of the dipoles in the array.

• "H" indicates the dipoles are oriented horizontally, so the antenna radiates horizontally polarized radio waves.
• "V" indicates the dipoles are oriented vertically, so the antenna radiates vertically polarized radio waves.

`!Second letter (if present)`!
Indicates whether the antenna has a reflector.

• "R" indicates that there is a simple (passive) reflector on one side of the array, so the antenna radiates a single beam.
• "RR" indicates that the array has some kind of "reversible reflector", so the direction of the beam can be switched 180°. Very few of this type have ever been built. `F33f`_`[RCI Sackville`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Radio_Canada_International]`_`f in Canada may have 2 HRRS type antennas—perhaps the only ones in North America.
• If "R" and "RR" are missing, the antenna has no reflector, so the dipole array will radiate its energy in two beams in both directions perpendicular to its plane, 180° apart.

`!Third letter (if present)`!

• "S" indicates that the array is steerable.

`!Numbers`!
Following the letters are three numbers: "x/y/z". "x" and "y" specifies the dimensions of the rectangular array of dipoles, while "z" gives the height above the ground of the bottom of the array:

• "x" (an integer) is the number of collinear dipoles in each horizontal row. (The number of columns in the array)
• "y" (an integer) is the number of vertically arranged dipoles in each column. (The number of rows in the array)
• "z" (a decimal fraction) is the height above ground in wavelengths of the lowest row of dipoles in the array.

For example, a "HRS 4/5/0.5" curtain antenna has a rectangular array of 20 dipoles, 4 dipoles wide and 5 dipoles high, with the lowest row being half a wavelength off the ground, and a flat reflector behind it, and the direction of the beam can be slewed. An HRS 4/4/0.5 slewable antenna with 16 dipoles is one of the standard types of array seen at shortwave broadcast stations worldwide.

`!Notes on HRS nomenclature`!

• HRS antennas of type HRS 1/1/z are undefined as such (such a thing would consist of just a single dipole).
• HRS antennas of type HRS 1/2/z and 2/1/z exist, but see little practical use in shortwave broadcasting. An antenna with the designation of "H 1/2/z" is commonly referred to as a "Lazy-H" antenna. VHF and UHF repeaters for FM radio or television in the `F33f`_`[UK`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=UK]`_`f quite often employ a pair of horizontal dipoles (or short yagis) one above the other (i.e. HRS 1/2/z) to concentrate transmission power in the vertical plane.
• The Russian `F33f`_`[Duga`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Duga_radar]`_`f `F33f`_`[Over The Horizon Radar`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Over_the_horizon_radar]`_`f may have used an antenna of type HRS 32/16/0.75 (estimated – not verified), with potential directional ERP in the gigawatt range.

>>HRS antenna

The `!HRS type antenna`! is one of the most common types of curtain array. The name comes from the above CCIR nomenclature: it consists of an array of `!H`!orizontal dipoles with a `!R`!eflector behind them, and the beam is `!S`!teerable. These antennas are also known as "HRRS" (for a `!R`!eversible `!R`!eflector), but the extra R is seldom used.

However, as far back as the mid-1930s, Radio Netherlands was using a rotatable HRS antenna for global coverage. Since the 1950s the HRS design has become more or less the standard for long distance (> 1000 km) high power `F33f`_`[shortwave`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Shortwave]`_`f broadcasting.

>>>HRS description

An HRS type antenna is basically a rectangular array of conventional dipole antennas strung between supporting towers.`:cite-ref-8[`F5bf`_`[8`#cite-note-8]`_`f] In the simplest case, each dipole is separated from the next by 1⁄2 `*λ`* vertically, and the centres of each dipole are spaced 1 `*λ`* apart horizontally. Again, in the simplest case (for a broadside beam), all dipoles are driven in phase with each other and with equal power. Radiation is concentrated broadside to the curtain.

Behind the array of dipoles, typically about 1⁄3 `*λ`* away there will be a "reflector" consisting of many parallel wires in the same orientation as the dipoles. If this was not present, the curtain would radiate equally forward and backward.

>>Steering

If there is an "S" in the antenna's designation, it is a steerable design. Following the ITU-recommendation, it might be called 'slewable design'.`:cite-ref-itu-rec-7-1[`F5bf`_`[7`#cite-note-itu-rec-7]`_`f] This might be achieved electronically by `F33f`_`[adjustment of the electrical wave phases`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Phased_array]`_`f of the signals fed to the columns of dipole antenna elements, or physically by mounting the antenna array on a large rotating mechanism. An example of this can be seen at `F33f`_`[NRK`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=NRK]`_`f Kvitsøy, where a circular railway carries a pair of wheeled platforms, each of which supports a tower at opposite ends of a diameter-arm. The curtain antenna array is suspended between the towers and rotates with them as the towers go around the circular railway. Another physical rotation technique is employed by the `F33f`_`[ALLISS`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=ALLISS]`_`f system where the entire array is built around a central rotatable tower of great strength.

Electrically slewed antenna arrays can usually be aimed in the range of ±30° from the antenna's physical direction while mechanically rotated arrays can accommodate a full 360°. Electrical slewing is typically done in the horizontal plane, with some adjustment being possible in the vertical plane.

>>Azimuth beamwidth

• For a 2-wide dipole array, the beamwidth is around 50°
• For a 3-wide dipole array, the beamwidth is around 40°
• For a 4-wide dipole array, the beamwidth is around 30°

>>Vertical launch angle

The number of dipole rows and the height of the lowest element above ground determine the elevation angle and consequently the distance to the service area.

• A 2-row high array has a typical takeoff angle of 20°

is most commonly used for medium range communications.

• A 4-row high array has a typical takeoff angle of 10°

is most commonly used for long range communications.

• A 6-row array is similar to a 4-row, but can achieve 5° to 10° takeoff angles.

can be used in shortwave communications circuits of 12000 km, and is highly directional.`:cite-ref-itu-rec-7-2[`F5bf`_`[7`#cite-note-itu-rec-7]`_`f]

Note that it is possible for details of the antenna site to wreak havoc with the designers plans such that takeoff angle and matching may be adversely affected.

>>Examples of HRS antennas

This is an example of theoretical HRS design shortwave relay stations. This may help one better understand HRS antenna directivity.

>>Shortwave relay stations using only HRS antennas

This is an incomplete list of stations using only HRS antennas, sorted by country name.

>>>Active sites

Brazil

• `F33f`_`[Empresa Brasil de Comunicação`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Empresa_Brasil_de_Comunicação]`_`f Parque do Rodeador

`F33f`_`[Germany`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Germany]`_`f

• `F33f`_`[T-Systems`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=T-Systems]`_`f `F33f`_`[Nauen`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Nauen_Transmitter_Station]`_`f

`F33f`_`[New Zealand`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=New_Zealand]`_`f

• RNZI `F33f`_`[Rangitaiki`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Rangitaiki]`_`f Plains

UK

• BBCWS `F33f`_`[Ascension Island`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Ascension_Island]`_`f
• BBCWS `F33f`_`[Rampisham`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Rampisham]`_`f
• BBCWS `F33f`_`[Skelton`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Skelton_transmitting_station]`_`f

• See : http://tx.mb21.co.uk/features/skeltonvlf/skelton3.shtml

• BBCWS `F33f`_`[Woofferton`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Woofferton_transmitting_station]`_`f

• See : http://tx.mb21.co.uk/gallery/woofferton/ Archived 2016-12-17 at the `F33f`_`[Wayback Machine`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Wayback_Machine]`_`f
• History : http://www.bbceng.info/Operations/transmitter_ops/Reminiscences/Woofferton/woof50y-v2.pdf

>>>Decommissioned sites

`F33f`_`[Australia`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Australia]`_`f

• CVC International, `F33f`_`[Darwin, NT`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Darwin,_NT]`_`f at Cox Peninsula. It was formerly a `F33f`_`[Radio Australia`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Radio_Australia]`_`f relay station. As the land has been turned over to aboriginal land owners in 2008 by a court decision, the site was dismantled in 2009. It is not currently known if there are any remaining HRS antenna towers.

Germany

• `F33f`_`[T-Systems`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=T-Systems]`_`f `F33f`_`[Wertachtal`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Wertachtal_transmitter_site]`_`f site, which is dismantled in 2014.

`F33f`_`[Canada`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Canada]`_`f

• `F33f`_`[Radio Canada International`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Radio_Canada_International]`_`f `F33f`_`[Sackville, NB`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Sackville,_NB]`_`f. Radio Canada International's shortwave service was shut down in June 2012 due to Canadian Broadcasting Corporation budget cuts as a result of reduced federal subsidies. The HRS antenna towers were demolished in 2014.

Spain

• `!Playa de Pals`! Radio Station Museum (the HRS antenna field is now a 12-hole golf course)

USA

• `F33f`_`[VOA`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=VOA]`_`f `F33f`_`[Delano, California`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Delano,_California]`_`f Relay Station (mothball status, could be reactivated in some emergency situations)
• `F33f`_`[VOA`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=VOA]`_`f Greenville-A Relay Station (Site was sold to `F33f`_`[Beaufort County, North Carolina`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Beaufort_County,_North_Carolina]`_`f in 2006, antennas were demolished in 2016.`:cite-ref-9[`F5bf`_`[9`#cite-note-9]`_`f])

>>>RADAR Systems using HR Type Antennas

Some portable tactical antenna systems still use HR type antennas, mostly not HRS as the antennas are rotatable.

>>References

`:cite-note-griffith-1`!1.`! `F0af`_`[↑`#cite-ref-griffith-1-0]`_`f `:citerefgriffith2000`aGriffith, B. Whitfield (2000). `*Radio-electronic Transmission Fundamentals, 2nd Ed`*. SciTech Publishing. p. 477. `F33f`_`[ISBN`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=ISBN_(identifier)]`_`f 1884932134.
`:cite-note-bray-2`!2.`! `F0af`_`[↑`#cite-ref-bray-2-0]`_`f `:citerefjohn-bray2002`aJohn Bray (2002). `*Innovation and the Communications Revolution: From the Victorian Pioneers to Broadband Internet`*. IET. pp. 73–75. `F33f`_`[ISBN`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=ISBN_(identifier)]`_`f 9780852962183.
`:cite-note-3`!3.`! `F0af`_`[↑`#cite-ref-3]`_`f `:citerefbeauchamp2001`aBeauchamp, K. G. (2001). `*History of Telegraphy`*. IET. p. 234. `F33f`_`[ISBN`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=ISBN_(identifier)]`_`f 0-85296-792-6. Retrieved 2007-11-23.
`:cite-note-4`!4.`! `F0af`_`[↑`#cite-ref-4]`_`f US Patent no. 1813143, `*Aerial System`* Archived 2013-11-09 at the `F33f`_`[Wayback Machine`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Wayback_Machine]`_`f, E. Bruce, filed Nov 25, 1927, granted July 7, 1931
`:cite-note-sterba-5`!5.`! `F0af`_`[↑`#cite-ref-sterba-5-0]`_`f US Patent no. 1885151, `*Directive antenna system`* Archived 2012-01-27 at the `F33f`_`[Wayback Machine`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Wayback_Machine]`_`f, E.J. Sterba, filed July 30, 1929, granted November 1, 1932
`:cite-note-6`!6.`! `F0af`_`[↑`#cite-ref-6]`_`f Broadband curtain antennas for shortwave broadcasting (PDF) (antenna brochure) (in German). Ulm, DE: Telefunken, Fachbereich Hochfrequenztechnik. 1976. Retrieved 2019-05-02. — includes antenna photos and structure diagrams.
`:cite-note-itu-rec-7`!7.`! `F0af`_`[↑`#cite-ref-itu-rec-7-0]`_`f "Transmitting antennas in HF broadcasting" (PDF). RECOMMENDATION ITU-R BS.80-3. Retrieved 2019-07-22.
`:cite-note-8`!8.`! `F0af`_`[↑`#cite-ref-8]`_`f http://www.antenna.be/tci-611.pdf
`:cite-note-9`!9.`! `F0af`_`[↑`#cite-ref-9]`_`f `:citerefwitn`aWITN. "NEW VIDEO - Implosions bring down 48 VOA towers in Beaufort County". `*www.witn.com`*. Archived from the original on 2019-06-29. Retrieved 2019-06-13.

>>External links

ALLISS Technology portals

• http://HireMe.geek.nz/ALLISS.html Archived 2022-07-07 at the `F33f`_`[Wayback Machine`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Wayback_Machine]`_`f
• http://www.w8ji.com/curtain%20sterba%20USIA%20array.htm

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