An antenna rotator (or antenna rotor) is a device used to change the

orientation Orientation may refer to: Positioning in physical space * Map orientation, the relationship between directions on a map and compass directions * Orientation (housing), the position of a building with respect to the sun, a concept in building des ...

, within the

horizontal plane Horizontal may refer to: *Horizontal plane, in astronomy, geography, geometry and other sciences and contexts *Horizontal coordinate system, in astronomy *Horizontalism, in monetary circuit theory *Horizontalidad, Horizontalism, in sociology *Hor ...

, of a

directional antenna A directional antenna or beam antenna is an antenna that radiates or receives greater radio wave power in specific directions. Directional antennas can radiate radio waves in beams, when greater concentration of radiation in a certain directio ...

. Most antenna rotators have two parts, the rotator unit and the controller. The controller is normally placed near the equipment which the antenna is connected to, while the rotator is mounted on the antenna mast directly below the antenna. Rotators are commonly used in

amateur radio Amateur radio, also known as ham radio, is the use of the radio frequency radio spectrum, spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emer ...

and military communications installations. They are also used with TV and FM antennas, where stations are available from multiple directions, as the cost of a rotator is often significantly less than that of installing a second antenna to receive stations from multiple directions. Rotators are manufactured for different sizes of antennas and installations. For example, a consumer TV antenna rotator has enough

torque In physics and mechanics, torque is the rotational analogue of linear force. It is also referred to as the moment of force (also abbreviated to moment). The symbol for torque is typically \boldsymbol\tau, the lowercase Greek letter ''tau''. Wh ...

to turn a TV/FM or small

ham Ham is pork from a leg cut that has been preserved by wet or dry curing, with or without smoking."Bacon: Bacon and Ham Curing" in '' Chambers's Encyclopædia''. London: George Newnes, 1961, Vol. 2, p. 39. As a processed meat, the term '' ...

antenna. These units typically cost around

US$ The United States dollar (Currency symbol, symbol: Dollar sign, $; ISO 4217, currency code: USD) is the official currency of the United States and International use of the U.S. dollar, several other countries. The Coinage Act of 1792 introdu ...

70 . Heavy-duty ham rotators are designed to turn extremely large, heavy,

high frequency High frequency (HF) is the ITU designation for the band of radio waves with frequency between 3 and 30 megahertz (MHz). It is also known as the decameter band or decameter wave as its wavelengths range from one to ten decameters (ten to one ...

(

shortwave Shortwave radio is radio transmission using radio frequencies in the shortwave bands (SW). There is no official definition of the band range, but it always includes all of the high frequency band (HF), which extends from 3 to 30 MHz (app ...

) beam antennas, and cost hundreds or possibly thousands of dollars. In the center of the reference picture, the accompanying image includes an AzEl installation rotator, so named for its controlling of both the

azimuth An azimuth (; from ) is the horizontal angle from a cardinal direction, most commonly north, in a local or observer-centric spherical coordinate system. Mathematically, the relative position vector from an observer ( origin) to a point ...

and the

elevation The elevation of a geographic location (geography), ''location'' is its height above or below a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational equipotenti ...

components of the direction of an antenna system or array. Such antenna configurations are used in, for example,

amateur radio satellite An amateur radio satellite is an artificial satellite built and used by amateur radio operators. It forms part of the Amateur-satellite service. These satellites use amateur radio frequency allocations to facilitate communication between amate ...

or moon-bounce communications. SatNOGS_v2_in_FOSDEM_2015

An open hardware AzEl rotator system is provided by the

SatNOGS SatNOGS (Satellite Networked Open Ground Station) project is a free software and open source hardware platform aimed to create a satellite ground station network. The scope of the project is to create a full stack of open technologies based on ope ...

Groundstation project. The Alliance Manufacturing Co. of Alliance, Ohio, and the Astatic Corporation of Conneaut, Ohio, manufactured popular radio and TV booster and rotary antenna systems. These products were heavily advertised for radio use in newspapers starting in the early 1940s, and for use with commercial television sets from 1949 into the 1960s.

Cinécraft Productions Cinécraft Productions, Inc. is a privately held American sponsored film and Television studio, video production studio in Cleveland, Cleveland, Ohio. The studio is said to be the longest-standing sponsored film and video production house in th ...

, a pioneer in early TV advertising, produced six commercials for the Astatic Booster TV in 1949 and 112 for the Alliance Tenna-Rotor, Tenna-Scope, and Casca-Matic Booster between 1949 and 1955.https://digital.hagley.org/islandora/search/tenna-rotor?type=edismax&cp=islandora%3A2623872 https://findingaids.hagley.org/repositories/2/archival_objects/432700

Manufacturers of consumer TV antenna rotators

Past

Before the era of

cable TV Cable television is a system of delivering television broadcast programming, programming to consumers via radio frequency (RF) signals transmitted through coaxial cables, or in more recent systems, light pulses through fibre-optic cables. This ...

and the rise of

satellite TV Satellite television is a service that delivers television programming to viewers by relaying it from a communications satellite orbiting the Earth directly to the viewer's location.ITU Radio Regulations, Section IV. Radio Stations and Systems ...

, many homes had outdoor antennas designed to capture

over-the-air television Terrestrial television, or over-the-air television (OTA) is a type of television broadcasting in which the content is transmitted via radio waves from the terrestrial (Earth-based) transmitter of a TV station to a TV receiver having an ant ...

signals. The rotator market was served by a number of manufacturers including * Alinco Electronics, Inc. *Alliance Manufacturing Co., Inc.,

Alliance, Ohio Alliance is a city in Stark County, Ohio, United States. The population was 21,672 at the 2020 United States census, 2020 census. It was established in 1854 by the merger of three smaller communities and was a manufacturing and railroad hub in t ...

* American Phenolic Corporation * Astatic Corporation.

Conneaut, Ohio Conneaut ( ) is the northeastern most city in Ashtabula County, Ohio, United States, as well as the entire state as a whole. Located in the Greater Cleveland, Cleveland metropolitan area, it is settled along Lake Erie at the mouth of Conneaut Cre ...

Channel Master Channel Master is a manufacturer of TV antennas and accessories that once employed 1,600 people. History The original company, now defunct, was founded in Ellenville, New York, in 1949 by 23 year-old former Merchant Marine radio operator a ...

* Cornell-Dubilier Corporation,

South Plainfield, New Jersey South Plainfield is a Borough (New Jersey), borough in northern Middlesex County, New Jersey, Middlesex County, in the U.S. state of New Jersey. The borough is situated on the border with Union County, New Jersey, Union County in the Raritan Riv ...

* Gemini Industries, Inc.,

Passaic, New Jersey Passaic ( or ) is a City (New Jersey), city in Passaic County, New Jersey, Passaic County, in the U.S. state of New Jersey. As of the 2020 United States census, the city was List of municipalities in New Jersey, the state's 16th-most-populous ...

* Hy-Gain * Kenpro * Lance Industries,

Sylmar, California Sylmar is a suburban neighborhood in the San Fernando Valley and the northernmost neighborhood within the city of Los Angeles, California, United States. Historically known for its profusion of sylvan olive orchards, Sylmar can trace its past t ...

* Leader Electronics, Inc.,

Cleveland, Ohio Cleveland is a city in the U.S. state of Ohio and the county seat of Cuyahoga County, Ohio, Cuyahoga County. Located along the southern shore of Lake Erie, it is situated across the Canada–United States border, Canada–U.S. maritime border ...

* Nippon Antenna *

Philco Philco (an acronym for Philadelphia Battery Company) is an American electronics industry, electronics manufacturer headquartered in Philadelphia. Philco was a pioneer in battery, radio, and television production. In 1961, the company was purchase ...

Philips Koninklijke Philips N.V. (), simply branded Philips, is a Dutch multinational health technology company that was founded in Eindhoven in 1891. Since 1997, its world headquarters have been situated in Amsterdam, though the Benelux headquarter ...

* Pro Brand International, Inc. (Eagle Aspen brand) * Radio Merchandise Sales, Inc. *

Radio Shack RadioShack (formerly written as Radio Shack) is an American electronics retailer that was established in 1921 as an amateur radio mail-order business. Its parent company was purchased by Tandy Corporation in 1962, which shifted its focus from ma ...

RCA RCA Corporation was a major American electronics company, which was founded in 1919 as the Radio Corporation of America. It was initially a patent pool, patent trust owned by General Electric (GE), Westinghouse Electric Corporation, Westinghou ...

* Sears, Roebuck and Co. *Stolle * The Radiart Corp.,

Zenith The zenith (, ) is the imaginary point on the celestial sphere directly "above" a particular location. "Above" means in the vertical direction (Vertical and horizontal, plumb line) opposite to the gravity direction at that location (nadir). The z ...

Current

Although the

cord-cutting In broadcast television, cord-cutting refers to the pattern of viewers, referred to as cord-cutters, cancelling their subscriptions to multichannel television services available over cable or satellite, dropping pay television channels or reducing ...

movement has increased interest in receiving free over-the-air television signals, as of December 2021 consumer options are limited. *VOXX Accessories Corporation of

Carmel, Indiana Carmel () is a suburban city in Hamilton County, Indiana, United States, immediately north of Indianapolis. With a population of 99,757 as of the 2020 United States census, 2020 census, the city spans across Clay Township, Hamilton County, Indi ...

, a wholly-owned subsidiary of

VOXX International Voxx International Corporation was an American consumer electronics company founded as Audiovox Corporation in 1960, and renamed Voxx in 2012. It was headquartered in Orlando, Florida. The company specialized in four areas: OEM and after-mark ...

, using the RCA trademark, offers a remote-controlled antenna rotator, the model VH226E.
Channel Master's stock of model CM-9521HD is depleted
and it is unclear whether more units will be manufactured. * Yaesu Musen sells a range of rotators aimed at the Amateur and FM (VHF) broadcast listener markets. Amateur products include an Azimuth-Elevation product.

References

External links

Alliance Tenna-Rotor Series 1-17 television commercials
produced by Cinécraft Productions, Inc.
Yaesu Rotators
{{DEFAULTSORT:Antenna Rotator Antennas Rotation