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TV Antenna - Digital TV Antenna - HDTV Antenna ...
The "TV-Antenna" … déjà vu – Again? |
Do you really need a TV-Antenna for Digital-HDTV? Does anyone? Between Cable TV and DBS (Direct Broadcast Satellite) TV, are there any Viewers still using an antenna to receive TV signals? And if so, why?As a matter of fact - Yes! The number of American families dependent entirely on Local OTA TV Broadcasts, as their only means of receiving any TV programming, is estimated at between 16-Million and 20-Million Households (based on average results from several separate surveys). All of these viewers require some type of TV-Antenna in order to receive TV signals. Anyone old enough to remember TV during the “50’s” and “60’s will recall what the typical skyline above every town and community looked like – a metallic-forest of TV-Antennas with aluminum branches reaching out from each roof-top, their skeletal-fingers pointing in all directions.
Then, as Cable TV gained predominance in the “70’s” and “80’s,” gradually the ubiquitous TV-Antenna disappeared – first from the larger metropolitan areas, and eventually, even from most suburban communities.
At the present time, Cable TV is the primary source of television programming for the majority of U.S. TV viewers; additionally, multiple-millions of viewers are DBS (Direct Broadcast Satellite) TV subscribers.
Today, nation-wide, a majority of homes have multiple TV sets; and though Cable TV or Satellite TV may be the primary TV provider, frequently the second, |
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third (etc) TV is connected to some type of TV-Antenna (often a set-top – “rabbit-ear” antenna) for receiving Local TV Broadcasts.
But now a new trend may be emerging.
Many Cable and Satellite TV Subscribers are reconsidering OTA TV; this has created a new interest in the 'old' TV-Antenna. Since more Local TV Stations are providing Network programming (as well as some local programs) in HDTV, viewers have found an optional way to obtain HDTV programs.
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Connecting to a TV-Antenna often results in improved picture quality, and the HDTV programs are free. With an increasing number of HDTV owners, there are more and more viewers, demanding more HDTV programming. With Local OTA Broadcasts offering more HDTV choices – and “Free” HDTV at that – the renewed consumer interest in TV-Antennas is understandable. |
Antenna Choices
Just as buying a new TV has changed, shopping for a TV-Antenna today, can be confusing; but it need not be. Although they may be labeled: "TV-Antenna", "Digital TV-Antenna" or "HDTV Antenna" - the consumer should not be misled. A TV-Antenna that can receive traditional Analog TV Signals, is NOT different than an Antenna that receives Digital-HDTV Signals. Manufacturers and Retailers are merely taking advantage of the current, heightened Consumer interest in all things related to Digital-HDTV. However, a TV-Antenna does not discriminate between Analog TV and Digital / HDTV Signals.
The "Right" TV-Antenna - For You … (For Your Location)
The CEA - Consumer Electronics Association has a great Website where consumers can immediately get a list of Local TV Stations broadcasting within range of their location, along with other details useful in getting optimal TV-Antenna Reception; and all the information is customized for each person’s zip code or street address.
This information includes: Local Station's Call-Letters, Channel Number, assigned frequency used to transmit, identifies which TV Stations are presently transmitting both Digital and Analog Signals, the approximate distance from the viewer's address to the Station's Transmitter, as well as the compass-heading (in 'degrees') for accurately pointing the Antenna in the exact direction of the transmitter.
And there's more ...
The chart also includes a color-coded "Antenna Selection Guide" which shows the "type" of TV-Antenna most suitable to receive each Local Station's Signal in a specific area.
(Use this Link To Go To: CEA's Antenna Web to determine which Antenna Type is best suited for your location)
Antenna Color-Coded Selection Guide
The Antenna Color Codes indicate different zones; and identify the type of TV Antenna best suited for optimal reception, in each zone.
In general, the closer you live to the transmitter-tower, the better reception you can expect. And naturally, the farther away, the opposite is true. However, there are a number of variables involved which can affect TV reception, and these also play a role in determining which Type of Antenna you need.
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When selecting a TV-Antenna, look for the 'CEA-Certified Code-mark’, which is displayed on the external packaging; this will correspond to the CEA Color-code that was used on your customized Local Stations List, on the CEA Website |
Antenna Description – Size and Usage Zone
SMALL MULTI-DIRECTIONAL
- DESCRIPTION: The smallest of TV-Antennas; reception of signals from all directions.
- APPEARANCE: Attractive design; including novel shaped disk and patch antennas, and antennas that attach to satellite systems.
- USE: In yellow color code areas where signal strength is highest and away from reflecting structures or low areas.
MEDIUM MULTI-DIRECTIONAL
- DESCRIPTION: Somewhat larger and slightly more powerful.
- APPEARANCE: A variety of novel shaped antennas can be found in this group ... including: stick, wing shaped and disk antennas with long elements.
- USE: Green color code areas. An amplified antenna is recommended in the green area anytime a long (20 feet or more) cable run from the antenna is required, or when more than one device (TV or VCR) is to be used with an antenna. They work best away from reflecting structures or low areas.
LARGE MULTI-DIRECTIONAL
- DESCRIPTION: Bigger in size, these antennas receive more signal power. Better for greater distances from signal source and areas with low signal strength.
- APPEARANCE: These antennas can be used to reject simple ghost situations.
- USE: When mounted at rooftop heights (30 feet or higher) outdoors, amplified antennas can be used in light green color code areas away from reflecting structures or low areas.
SMALL DIRECTIONAL
- DESCRIPTION: Antennas that act like large multidirectional on channels 2-6 but on higher channels these antennas start to have useful ghost reducing effects. Picture quality is excellent when no signal reflecting structures are around.
- APPEARANCE: Multi-element rooftop antennas.
- USE: Suitable for far edge of light green color code areas.
Amplified antennas with rooftop mounting can be used in these areas if the area is free of signal reflecting structures and is not in a low area.
MEDIUM DIRECTIONAL
- DESCRIPTION: Most popular rooftop antenna because of its modest size and ghost reducing characteristics.
- APPEARANCE: Multi-element rooftop antennas.
- USE: If there are ghost producing reflective structures near TV receiver antenna location, this kind of antenna is best for yellow, green, light green and red color code areas. Amplified antennas with rooftop mounting can be used with the blue color code.
LARGE DIRECTIONAL
- DESCRIPTION: Large antennas used in weak signal areas for maximum possible TV reception.
- APPEARANCE: Multi-element rooftop antenna.
- USE: Can be used in any color code area, but requires an amplifier and roof mounting for blue, violet and red color codes. Amplifiers are not recommended for yellow color codes.
Note: There is also a CEA-Certified label for "Indoor Antennae;" however, this label merely certifies that the indoor antenna is operational in a geographic area, considered appropriate for indoor antennae
CAUTION! TV-Antennas MAKE ideal electrical conductors!
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Do NOT attempt to install an Antenna if there is any chance of lightning... or if any electrical wires are located within 20-feet of the installation. Even if the width of the Antenna is less than 20-feet, an unexpected gust of wind can easily cause loss of control, bringing the antenna elements - And You - into contact with the electrical wires. |
TV-Antenna Components
The main components of an outdoor TV-Antenna are:
Elements, Boom and Phasing Lines Three Types of Elements:
- Director Elements: At the front of the antenna; smaller elements which initially pick up the signal.
- Driven (Driver) Elements: The element that the coax is connected to; it “Drives” the signal down, by way of the coax, to the television receiver (or an external receiver).
- Reflector Element: This is the longest element; located at the rear of the antenna, it reflects away (rejection) unwanted signals (from other transmitters or reflected signals from nearby physical structures which interfere with desired reception) while at the same time, reflecting desired signals coming from the front of the antenna, back to the Driven Elements.
The 'Boom' is the main-center section of an antenna; and the part to which the Elements are fastened. The antenna's Boom is commonly stronger, consisting of a larger-diameter aluminum tube than that of the Elements. Some larger types of TV-Antennas have a "double' or "twin" boom; in these the boom may be made up of two parts that are then fastened together.
The Phasing Lines can be aluminum wires or more rugged aluminum braces. The Phasing Lines enable the signal to be passed from the Driven Elements to the coax down-lead. In some antenna's the Boom, itself, acts as a Phasing Line - and is referred to as a “Hot Boom."Antenna Down-lead
The Down-lead is the "Coax" (Coaxial Cable) that carries the Signal from the TV-Antenna down to the TV receiver. The Coax can be routed through pipes, stapled to walls, held in place by "stand-off's," or simply taped to the mast with electrical tape.Good quality Coax is 95% shielded, provides excellent noise
| rejection, is durable and not affected by weather. While "RG-59" Coax is commonly available in retail stores, "RG-6" is preferred, since it has less 'signal-loss' than RG-59. Use RG-6 Coax in applications requiring cable lengths longer than (10 feet) and for all 'outside-the-house' installations. If you find that you must use RG-56, try to limit it to short (6-feet or less) lengths, inside the house - ie: as when connecting components to the TV. |
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TV Signal Strength and Picture Quality
The strength of the TV Signal (at the Antenna) depends on several factors
- Distance from transmitter: The farther the signal must travel, the weaker (fades) it becomes; the result is reduced picture and sound quality. Since UHF Signals weaken sooner, and can travel less distance, they are more difficult to receive, compared to VHF Signals. TV signals are composed of two carriers - video and audio. The video (picture portion) fades faster than the audio, which explains why sometimes you're able to receive sound, but not a picture.
- The terrain between your location and the transmitter: For instance, the transmitter is located at a high elevation (tall tower on top of a hill) and your house is located low in a valley - the TV Signals can 'over-pass' your location, above the reach of the antenna. Unlike AM-Radio Signals, which follow the curvature of the earth, TV Signals travel a straight line - "in tangent" to the earth; TV reception is based on "Line-of-sight" from the Transmitter to the receiving TV-Antenna.
- Other obstructions: (high buildings, hills, etc.) can also interfere with broadcast signals. Interference caused by buildings, water towers etc. can cause “ghosting” (multiple images visible on the TV screen) - the signal coming from the transmitter is reflected by an obstacle; this reflected signal arrives at your TV set, a fraction of a second later than the original signal, producing multiple images.
- Use of a "directional antenna" that has good side and rear rejection helps to eliminate or significantly reduce this "ghost-effect." However, sometimes "ghosting' can only be solved by relocating the antenna away from the reflecting obstacle.
- Type and Size Antenna: The size of Antenna needed depends on the distance from the transmitter to your location. The Antenna size, including length and number of elements, increases as distance between receiving location and transmitter increases.
In extreme fringe areas, stacking antennas (using multiple antennas on the same mast) can be a solution - if done correctly.
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