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High Definition Television   (HDTV)  ___________________________________

  History and Future of UHF TV

Before television first began, the Federal Communications Commission allocated twelve channels for television broadcasting. These channels, 2 through 13, are in the "very high frequency" or VHF band. (Originally Channel 1 was also included, but was soon reassigned to other purposes.) The tremendous growth in television broadcasting following World War II made it obvious that 12 channels were not enough.
So in 1952, the FCC allocated 70 additional channels above the VHF television band and called them "ultra high frequency" or the UHF band. These were channels 14 through 83.
Then in the early 1980's, channels 70-83 were reassigned and became cellular telephone frequencies. By the year 2010, channels 52 through 69 will be reassigned to uses other than TV broadcasting, due to the rapid growth in portable communication services. The UHF band will not lose 18 TV channels though. These TV channels will be incorporated into the new high definition television (H.D.T.V.) broadcasting standard, which can broadcast up to six digital channels in the same space as one analog channel. Using high definition television, TV stations will be able to broadcast a picture quality that is twice as sharp as the analog broadcasts of the past.
Digital broadcasting will also allow adjacent channel spacing of TV channels without creating interference between the two channels, making the broadcasting spectrum more efficient. .....more at tvantenna.com

  A Guide to UHF Television Reception
The purpose of this Guide is to provide information for improving UHF television reception in the home. The Federal Communications Commission originally allocated twelve channels for television broadcasting. These channels, numbers 2 through 13, are in the "very high frequency" or VHF band. (Originally Channel 1 was also included, but was soon reassigned to other purposes.)

The tremendous growth in television broadcasting following World War II made it obvious that 12 channels were not enough. So in 1952, the FCC allocated 70 additional channels above the VHF television band and called them "ultra high frequency" or UHF band. The channels are 14 through 83. UHF signals, however, due to the physics of radio frequency transmission, are inherently less efficient in the conversion of radio waves to the electrical signals used by the television receiver, and are subject to more losses from some environmental conditions then VHF. Good UHF reception, therefore, requires more attention to antenna installation and set tuning than does VHF reception. On the other hand some VHF channels are subject to certain types of interference to which UHF channels are generally immune.

Simply stated, clear UHF reception requires more attention to antenna installation and set tuning than does VHF reception. While the broadcasting industry is working to improve the technical elements of UHF reception, there is much that can be done, at reasonable cost, with present available equipment-and that's what this publication wants to reveal.

Perfect reception for television signals can't be guaranteed simply because there are too many variables involved. However, by following the recommendations in this Guide, the chances for clear reception will be greatly improved. Improving UHF reception can be a do-it-yourself job. Even if the work is given to a professional... more at www.indiana.edu.
  Congress gives OK to digital TV switch...

Congress decreed the end of TV as we know it, when the House of Representatives approved a $39 billion budget-cutting measure that requires broadcasters to turn off their current analog channels by 2009.

The budget legislation, approved on a razor-thin 216-214 vote, makes modest cuts to Medicaid, Medicare and student-loan subsidies and adds $10 billion in new revenue from auctioning television airwaves to the highest bidder.

A nearly identical bill passed the House in December '05, but it had to vote on the legislation again because Senate Democrats forced technical changes that the House needed to accept before the bill could be sent to President Bush's desk.

Rep. Joe Barton, R-Texas, chairman of the House Commerce Committee, said setting a February 17, 2009, date to end analog TV transmissions signals "a great technical revolution that has been in the making for years will finally be complete."

Barton has been one of the lead lawmakers in the push for a "hard date" for the transition to DTV.

Although most of the debate over the "Deficit Reduction Act" was concerned with cuts in welfare and other social programs, the legislation also would end the transmission system broadcasters have used since the dawn of the television era.

Under the legislation, broadcasters will have to end their analog broadcast, switching to digital television. DTV gives broadcasters the ability to air one or two high-definition TV channels or several standard-definition channels. HDTV gives viewers a movie-quality picture and CD-quality sound.

The DTV transition has been grinding along for decades. Under current law, broadcasters are required to vacate their current frequencies this year or when digital TV reaches 85% of the television audience, whichever is later. Critics have contended that the 85% threshold is unlikely to be reached.

While about 16% of U.S. television watchers do not get cable or satellite TV and depend on over-the-air transmissions, there are many more TVs that use only an antenna to receive programming.

In order to prevent families from being cut off from their TVs, Congress has included a maximum of $1.5 billion for set-top boxes or other means to receive digital signals. Each family in the program would be eligible for up to $80 for the conversion. The National Association of Broadcasters estimates that there are 73 million TV sets operating nationwide.

High Definition Television   (HDTV)  ____________________________ blog/broadcast