What’s next?
While you are waiting for your DTV coupons to arrive in the mail, (you did order them from www.DTV2009.org or 1-888-388-2009 didn’t you?), you need to do some homework to learn what DTV is (and isn’t). You will be bombarded with terms, numbers, acronyms, lies, and deceptions that will rival any movie you have ever seen. The good news is any 8 year old can help, if all else fails.
Why are we changing to digital TV? The analog system we are using is called NTSC. It stands for National Television System Committee, and began as a black & white signal. They found a way to smear color on top of the black & white picture and kept it compatible with older sets. Many professionals like myself, say it stands for Never The Same Color. http://www.screenonline.org.uk/tv/technology/technology6.html has a pretty good explanation of why NTSC was chosen in the US. Recent upgrades like stereo in the Eighties, closed captioning, and V-chip data have been added to preserve the original NTSC signal. The technology has been good enough, but we have pushed it about as far as it can go, and it has some major limitations we’ll discuss later.
The DTV (Digital Television) system chosen for the US is called ATSC, for Advanced Television System Committee. When you go shopping for your converter box or next television set, look to see if it has both NTSC and ATSC tuner capabilities. Low power broadcasters will still broadcast analog on the air after June 12, 2009, so the NTSC tuner may still be useful. Some manufacturers may eliminate the NTSC tuner to keep the cost down, but the units I’ve seen in most stores work for both systems.
DTV offers new features like the program guide, more programming choices, and a crystal clear picture. It will also free up some channels for other uses, such as wireless Internet, as stations move off the upper UHF frequencies. It eliminates the VHF / UHF / Cable channel differences, or that “air / cable” menu setting that eliminates the UHF channels when set to cable and you want to use an antenna. The new receivers will scan the airwaves, and find all the channels for you.
The program guide is the key part of the signal that enables this. It is called PSIP, for Program and System Information Protocol. It tells your box how to tune in the DTV signals, which may contain a main channel and sub-channels. Stations can now broadcast more than one channel in the same space as the old system used, which is called multicasting. When it scans the airwaves, it will find our analog signal on channel 17, and then the digital signals, and display them as channel 17 for analog, 17-1 for our HD channel, 17-2 for our SD channel, and 17-3 for our 24 hour Weather Plus channel. You will use the channel up / down button on your remote, and never know the difference as the box does the hard work for you.
OK, I snuck in HD and SD on you. You are currently watching SD, which is Standard Definition Television, but DTV signals can be HD or High Definition. SD screens use a 4:3 ratio screen size, which is a little wider than it is tall. HD pictures are 16:9 ratio meaning it is much wider and closer to the ratio of a modern movie theatre screen. Your converter box will have to translate the size of the HD picture to display it on your SD TV set. It’s a rectangular peg in a square hole, and the results may not be pleasing to you. You have already been exposed to letter-boxed programs, which squeezes the picture down to fit inside the left and right sides of the screen, which leaves black boxes at the top and bottom of the screen, as if you are looking through a letterbox slot. It can be fine if you have a big screen SD set, but very annoying on smaller sets. Center cut is the best way to display HD on an SD set, but you will miss things on each side of the screen. Most programs are being shot to keep the 4:3 area safe, and there’s not much missing on the left and right sides. The last method to display HD on an SD set is the squeeze effect, which makes people look tall, skinny, and distorts proportions of objects in the scene. I recall many Clint Eastwood westerns where they did this to the end credits which really made him tall in the saddle!
We have covered several complicated topics here, so I’ll let you keep doing your homework and digest what you have learned so far. Next time we will discuss antennas, so you won’t want to miss it!
If you enjoyed this post, please consider leaving a comment or subscribe to the feed and get future articles delivered to your feed reader or email.
Comments
[...] What next Digital TV Posted by root 2 hours 23 minutes ago (http://dtv.myncblogs.com) Jul 21 2008 it stands for national television system committee and began as a black amp white signal they found a way to smear color on top of the black amp white picture and kept it compatible with older comment by edgar york on july 22 2008 11 33 am pow Discuss | Bury | News | What next Digital TV [...]
Subscribe to RSS
Can’t believe how remote I am located.Sears,Circuit city,Radio shack,Best buy,Kmart all are out of stock,not interested or informed,not reordering,DTV converter boxes.. It is a complicated unit to understand the many functions of the different units compare,select the one you need. Then after selecting and contacting the manufactuer (zenithDTT901) being told that BestBuy and circuit city will stitems,then finding local retailers do not conform.mA few stores have inferior productsbut out of44 types made only 3 are found in this area.coupons are expiring and products are not available.28387