page_title: Television antenna
section_title: Outdoor
hierarchical_section_title: Television antenna / Outdoor
caption_attribution_description: English: A basic dipole rabbit ear antenna weatherproofed and installed outdoors at height, receives full power stations at about 60 miles (97&#160;km).
context_page_description: A television antenna is an antenna specifically designed for use with a television receiver to receive over-the-air broadcast television signals from a television station. Terrestrial television is broadcast on frequencies from about 47 to 250 MHz in the very high frequency band, and 470 to 960 MHz in the ultra high frequency band in different countries. Television antennas are manufactured in two different types: "indoor" antennas, to be located on top of or next to the television set, and "outdoor" antennas, mounted on a mast on top of the owner's house. They can also be mounted in a loft or attic, where the dry conditions and increased elevation are advantageous for reception and antenna longevity. Outdoor antennas are more expensive and difficult to install, but are necessary for adequate reception in fringe areas far from television stations. The most common types of indoor antennas are the dipole and loop antennas, and for outdoor antennas the yagi, log periodic, and for UHF channels the multi-bay reflective array antenna.
context_section_description: When a higher gain antenna is needed to achieve adequate reception in suburban or fringe reception areas, an outdoor directional antenna is usually used. Although most simple antennas have  null directions where they have zero response, the directions of useful gain are very broad. In contrast, 
  directional antennas can have an almost unidirectional radiation pattern so the correct end of the antenna must be pointed at the TV station. As an antenna design provides higher gain (compared to a dipole), the main lobe of the radiation pattern becomes narrower.
  Outdoor antenna designs are often based on the Yagi-Uda antenna or log-periodic dipole array (LPDA). These are composed of multiple half-wave dipole elements, consisting of metal rods approximately half of the wavelength of the television signal, mounted in a line on a support boom.  These act as resonators; the electric field of the incoming radio wave pushes the electrons in the rods back and forth, creating standing waves of oscillating voltage in the rods. The antenna can have a smaller or larger number of rod elements; in general the more elements the higher the gain and the more directional. Another design, used mainly for UHF reception, is the reflective array antenna, consisting of a vertical metal screen with multiple dipole elements mounted in front of it.    
  The television broadcast bands are too wide in frequency to be covered by a single antenna, so either separate antennas are used for the VHF and UHF bands, or a combination (combo) VHF/UHF antenna. A VHF/UHF antenna is really two antennas feeding the same feedline mounted on the same support boom. Longer elements which pick up VHF frequencies are located at the "back" of the boom and often function as a log-periodic antenna. Shorter elements which receive the UHF stations are located at the "front" of the boom and often function as a Yagi antenna. 
  Since directional antennas must be pointed at the transmitting antenna, this is a problem when the television stations to be received are located in different directions. In this case two or more directional rooftop antennas each pointed at a different transmitter are often mounted on the same mast and connected to one receiver; for best performance  filter or matching circuits are used to keep each antenna from degrading the performance of the others connected to the same transmission line.  An alternative is to use a single antenna mounted on a rotator, a remote servo system that rotates the antenna to a new direction when a dial next to the television is turned. 
  Sometimes television transmitters are deliberately located such that receivers in a given region need only receive transmissions in a relatively narrow band of the full UHF television spectrum and from the same direction hence allowing the use of a higher gain grouped aerial.
caption: A rabbit ear indoor antenna weatherproofed and installed outdoors
exif: {"Image Make": "Apple", "Image Model": "iPhone 5c", "Image Orientation": "Rotated 90 CW", "Image XResolution": "72", "Image YResolution": "72", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "10.2", "Image DateTime": "2017:01:21 13:11:39", "Image YCbCrPositioning": "Centered", "Image ExifOffset": "204", "GPS GPSLatitudeRef": "N", "GPS GPSLatitude": "[42, 46, 1491/100]", "GPS GPSLongitudeRef": "W", "GPS GPSLongitude": "[77, 4, 417/100]", "GPS GPSAltitudeRef": "0", "GPS GPSAltitude": "54182/191", "GPS GPSTimeStamp": "[18, 11, 39]", "GPS GPSSpeedRef": "K", "GPS GPSSpeed": "0", "GPS GPSImgDirectionRef": "T", "GPS GPSImgDirection": "35086/315", "GPS GPSDestBearingRef": "T", "GPS GPSDestBearing": "35086/315", "GPS GPSDate": "2017:01:21", "GPS Tag 0x001F": "5", "Image GPSInfo": "1016", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "1420", "Thumbnail JPEGInterchangeFormatLength": "6008", "EXIF ExposureTime": "1/1022", "EXIF FNumber": "12/5", "EXIF ExposureProgram": "Program Normal", "EXIF ISOSpeedRatings": "50", "EXIF ExifVersion": "0221", "EXIF DateTimeOriginal": "2017:01:21 13:11:39", "EXIF DateTimeDigitized": "2017:01:21 13:11:39", "EXIF ComponentsConfiguration": "YCbCr", "EXIF ShutterSpeedValue": "18846/1885", "EXIF ApertureValue": "4845/1918", "EXIF BrightnessValue": "10081/1041", "EXIF ExposureBiasValue": "0", "EXIF MeteringMode": "Pattern", "EXIF Flash": "Flash did not fire, auto mode", "EXIF FocalLength": "103/25", "EXIF SubjectArea": "[1631, 1223, 1795, 1077]", "EXIF SubSecTimeOriginal": "669", "EXIF SubSecTimeDigitized": "669", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "3264", "EXIF ExifImageLength": "2448", "EXIF SensingMethod": "One-chip color area", "EXIF SceneType": "Directly Photographed", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Auto", "EXIF FocalLengthIn35mmFilm": "33", "EXIF SceneCaptureType": "Standard", "EXIF LensSpecification": "[103/25, 103/25, 12/5, 12/5]", "EXIF LensMake": "Apple", "EXIF LensModel": "iPhone 5c back camera 4.12mm f/2.4"}