My previous post about Analog TV, Digital TV and Its Wonders (yes, that's three categories) has prompted a number of responses, including some information a less-than-informational nature.
This is about par for the course. The newspapers have been, shall we say, not all that helpful, while TV station News departments have been largely ignoring the whole thing (ew, ick, Engineering) in the hope it would go away.The Basics:
First off, yes, analog TV will (mostly) shut down in February 2009. (The little low-power stations have, per the most recent word, until 2012 to make the switch to digital).
Yes, that means grand-dad's fridge-sized RCA with the big, big 12" screen won't be able to pick up stations, no more than it ever was able to tune in UHF.... And there's the rub. As one commenter has already discovered, converter boxes are coming on the market. They hook up between your rabbit ears or outside antenna and the antenna input or audio-video inputs of your present TV and tune in all flavors of HDTV, converting it down to standard-resolution; while you won't get any better a picture than your TV is presently capable of giving you, you will
get everything it can do, picture quality as good as you're getting from a DVD player. You're probably not getting a picture that good over the air or via analog cable right now.
So you will
have to buy something to keep on gettin' free TV, and you can thank the Grand Alliance of set makers, computer companies and film studios for that; but it is not a whole new
overpriced Red Chinese
, um, somewhat to the high end of affordable but nifty HDTV set.
In fact, with a converter, you can even keep on recording things in 525-line standard-definition. Just put the converter box ahead of your VCR or DVD recorder or video server.
Cable and satellite TV companies will also still be pumping out analog-compatible TV to to the paying customers -- also to that lowlife across the alley who hooked up his own, at least 'til they find him out.
Stations were assigned DTV power levels that gave them coverage equal to their analog coverage. In practice, since a digital TV signal is either great or gone -- and ATSC is way more so than the encoding used for satellite TV -- this means the "fringe areas" are now gonna get decent pictures.Spectral Recovery:
Yes, the FCC will begin saving ghosts.... Or not. And the DTV/HDTV signals are exactly as wide, per channel, as the old analog ones. Oh, just barely; we have to jump up an' down on 'em to get them to fit and even at that, part of my job consists of goin' around every so often an' givin' the stuff that stuffs it all down a good, solid whack wherever it's bulging.Howsomever,
we can do a cute trick with DTV that we could not do with analog. While a cable company can use all or most the channels, 2-3-4-5-6-7-8-9-10-11-12-13-14-15-16....99999 by dint of havin' it all in one wire where they can fuss with it but channel assignment for over-the-air analog TV is one of the very darkest of Dark Arts; this is why you will often find similar groupings of channel assignments in different cities. All those "extra" channels are needed so the stations can be assigned channels in such a way as to not interfere with one another (at least on paper). This is not
true of DTV; those channels can be stacked up side by side by side, without interference.
Can be and are. Some bright lad at the Grand Alliance put a bug in the ear of some bright lad at the FCC, and they worked out there were a whole lot of channels on the UHF end nobody was going to need. So no new channels were assigned up there and the stations that already were there got told not to leave anything behind when they packed up for their new DTV channels. The vacated space was auctioned off for public-safety and other two-way radio uses, including some data comms. The original plan was to clean out not only the top end of UHF but the very bottom of VHF as well. This foundered on two things: low-band VHF stations (2-6) have been groovin' for years on havin' signals that could be picked up from Big City to Bugtussle (and, when the wind is right, in Far Forn Parts) , which they did not care to give up; while, conversely, no two-way user was seriously interested in such low frequencies.
So the Feds ended up "owning" (?!!!) some shiny-new spectrum, which they promptly put to work hailin' traffic on the nearest street corner. 'Course, it won't have any place to go
until 2009 and the cars are backin' up, so you can see that the odds of that Feb '09 date gettin' pushed back or set aside are, well, as slim as a crack whore.In Summation:
I. DTV picture quality and sound are really good.
Even with a converter box ahead of your old TV, you'll see some improvement. (If you have really, really
bad ghosting, there is a slight chance you won't see nothin' -- see, it's either there and good, or it's gone. That's digital for ya).
II. Save your Steam-Powered TVs. They can still be made to work. If you have cable or satellite, you're home free.
III. Wave bye-bye to the upper UHF channels. There was never anything good there anyway. Besides, it'll still be on the air, just at a lower number. Though your TV may lie to you about it.
IV. This was not the TV stations' idea. It wasn't even thunk up by the networks. On the other hand, the TV set market was pretty much saturated and the TeeVees were lastin' a long, long time. Something that would make people go buy new tellyvisions, h'mmm, cui bono
? Yeah. Them. The spectrum sell-off was just the bait the Feds lunged for. (Look for some "buyer's remorse" posturing in Congress as the deadline approaches. Also lines like, "technological disenfranchisement," which translates into, "free TVs or converters for the people in my district whose votes I am courting." Your tax dollars at work).
________________________________1. I'm pretty sure they helped start WW I, too.
2. HDTV standards counterpart in resolution and screen shape to what we get from 525-line analog is called, confusingly, 480i; each number refers to the number of horizontal lines per image but the older term uses the total number of 'em including the ones that are working behind the scenes to keep everything in sync while the newer term just uses the number of lines actually displayed. The "i" tells us it's knitting the picture like fancy socks, alternately sending the interlaced odd-numbered and even-numbered lines to fool your eye all the better. Other common resolutions are 720p ("progressive," all the lines of the picture one after another in order in the manner of a computer monitor), 1080i, and -- not over the air -- 1080p. Nobody could figure out how to stuff all of 1080p in the teeny little box we have to cram the pix into to get them through the air. Or at least they couldn't a decade ago.
3. They also cheat -- starting with 14, none of them are on the same frequencies as the over-the-air channels of the same number. This can lead to big fun for radio hams and other users of two-way radio when the cable system leaks signals. Which they do.
4. Most every other station has the option, come 02-2009, to stay on their DTV channel or return to their old channel in their coat of many digital colors -- and the software is set up to lull your DTV set into believing they've been on the same channel all along.
5. This terminology may irk English- or 'Strine-speaking overseas readers, who are used to thinking of TV channels as not being so very much in one "band" or another and get their local high-fidelity, frequency-modulation stereo radio signals on VHF. US terminology differs. It's all part of the fun, really.