February 17, 2009 should be an interesting time in the US. Any TV stations still operating analog (NTSC) transmitters that day must shut them down at midnight. Without a converter box or a television, DVD/VCR, DVD Recorder with a digital (ATSC) tuner all you will get is static.
The transition process started in earnest in 1996 when the FCC allocated additional channels to TV stations so they could bring up their digital transmission equipment and antennas while still operating their analog transmitters/antennas. Between now and February 2009 these stations will be shutting down their old analog systems so the federal government can auction off part of this spectrum for other uses.
While this has some obvious issues for home viewers, the concerns for professional AV systems have been less clear. The most obvious issue relates to TV or cable TV tuners used in AV systems. While we don’t design many professional AV systems with over-the-air antennas, there are some out there, and the tuners in those systems will need to be updated. For most professional AV systems, we may display cable TV or satellite TV using a set-top box. Since the providers of these boxes are not using public airwaves, they are not required to convert all of their programming to digital signaling by the deadline. Of course, many are interested in offering the latest and greatest to their customers, so they too have begun the transition to digital – albeit more slowly than over-the-air broadcasters. Whatever transition method they choose, they will accomplish it by changes to their decoder boxes on their own schedules, so no great concern for professional AV there.
Over the last several years, the FCC has been mandating that consumer equipment with built-in analog TV tuners also include a digital tuner. The mandate first applied to larger TVs and worked its way down through the product line, and as of last year applied to all new equipment with a built-in tuner. (This does not apply to monitors, projectors, and other equipment that traditionally does not have tuners.)
So what is the impact on professional AV systems? If any device in an AV system provides digital signals, then the rest of the system – from source to destination, or tuner to projector – needs to be able to support the digital signal as well. (The alternative is to convert the digital signal back to analog and leave everything in the rest of the signal path alone. You lose the benefits of digital, but then again you don’t have to invest in new equipment to make the change.)
Most newer projectors have been able to display digital signals for several years now. While few actually display HDTV (wide aspect ratio) signals using a native, wide aspect ratio chip (meaning their LCD/DLP chips are not 16 x 9 aspect ratio) they all can display the signal by scaling it to fit a 4 x 3 chip. Most audiovisual switchers and other internal AV gear have been able to transmit digital signals for some time. So unless you have a really old professional AV system and you are using over-the-air feeds, you should not have to worry about this area of the conversion unless you want to upgrade and get the benefits of digital signals and/or wide screen aspect ratio that these systems have to offer.