Posted on 05/27/2008 9:44:33 PM PDT by primeval patriot
With preparations for the DTV (Digital Television) cutover in the U.S. gaining momentum, many people have already questioned the government's preparedness. Now it appears that at least one of the preparations that has been made is even in question. The FCC may be greatly overestimating the effective range of DTV broadcasts. If that's true there may be millions of Americans who are unable to receive the same selection of channels they're currently getting via analog broadcast.
The issue is signal degradation. One major advantage of DTV is that the quality is relatively even for everyone who recieves a particular broadcast. The reason for this is that, unlike analog broadcasts, when a digital signal degrades to the point where analog image or sound quality would suffer it simply drops out completely. Rather than getting a lower quality picture you get none at all.
While FCC officials believe most viewers will be able to receive the same channels digitally that they do now, a study from a market research firm in Los Angeles called Centris casts doubt on those claims. According to the Centris study, which claims to be based on a more detailed model than the federal government has been using, the government figures are overly optimistic. Centris claims that nearly 6 million households will need outdoor antennas to keep receiving the same selection of channels they're currently getting.
If that weren't bad enough, according to the consultant hired to replace the antennas on the Empire State Building real world signal measurements paint an even more pessimistic picture. A study of the first HDTV station by Oded Bendov found that digital signals did not travel as far as either model had predicted. “For the people with rabbit-ear antennas, I would say at least 50 percent won’t get the channels they were getting,” Dr. Bendov said. “I would say a lot of people are going to be very unhappy.”
With analog signals scheduled to be shut off a year from now, it appears that U.S. consumers may get to pay the price for the FCC's lack of real planning.
Get DIRECTV and be done with it. Best move you will ever make.
What I want to know is, if the box is for people without cable or sat TV, why do I always see commercials for the rebates for the boxes on cable channels?
I have found that there are small differneces between models as far as sensitivity goes too... no specs on any of these things.
Aren't all the new channel designations in the UHF band? I thought the VHF freqs were the ones sold off. Anyway, a good UHF antenna and amp will help out, if people want to go to the trouble.
Just out of curiosity, have you checked the FCC license site for the various stations you’re discussing? A large number of stations going digital are running lower power on the digital side at the moment to save power costs, but planning to ramp it up once they can shut off the analog transmitter. You’ll find the TV lookup info here:
http://www.fcc.gov/fcc-bin/audio/tvq.html
How’s your reception on Channel 39? The Digital stations will all be broadcasting on the UHF band, so if you’re not using an all-band antenna, you won’t be getting much of a signal from them. 39 at the moment is broadcasting 5 million watts on the analog side, and one million on the digital side on channel 40. If you’re not getting 39 in analog, you’re probably not going to get 40, and you’re also probably not going to get much else in the way of UHF digital stations. The problem there isn’t an analog versus digital problem the problem is a VHF versus UHF problem.
If the Tyler station you’re talking about is KLTV, they’re running the legal maximum analog on channel 7 at the moment, and they’ll be one of the few digital stations still operating in the VHF band (on channel 10). They’re currently only using 15 thousand watts on the digital side, which could explain your spotty reception.
Yeah, that's the plan. There'll be an exception for the southern border areas for a while, though. A lot of the VHF frequencies are going to public safety use. A lot of what the posters above have described as 'digital problems' are actually related to the difference between UHF and VHF propagation. VHF bends a bit around terrain obstructions, UHF is more line-of-sight. Lots of folks have VHF-only antennas. Those who are currently getting decent signals off their local UHF stations should be able to make the switch fairly painlessly.
Wasn't it Colin Powells son who was in charge at the FCC when all this decision making to switch to digital tv and sell the frequencies was made?... and isn't he still in the position to receive millions as a result? Bureaucratic mandarins will be the death of this country...
The frequencies to be auctioned off are in the 700 MHz range, which are channels 51 and up. That’s the channel range that the broadcasters are having to vacate. Many who were up there already have left; the remainder must do so by the time of the analog turnoff next year.
The final landing places for the DTV broadcasters will be channels 2-50, IIRC. Some broadcasters will move their DTV transmissions onto their original analog channels, some won’t. Interestingly, because of the “brand identification” value of a TV station’s traditional channel number, their DTV transmitter can cause your set to display that number even though it’s really coming in on some other channel!
Industry lore says to avoid channels 2-6 for DTV because of the types of (non-TV) interference that exist at those frequencies.
Therein lies a major bone of contention. The FCC and all their consultants calculated that a DTV transmitter would need only about a tenth of the power of an analog transmitter (all other things, such as channel number, being equal) to get comparable coverage. So of course that was the FCC's default assignment to stations for their DTV transmitters. Station managers are looking forward to big savings on their power bills! Chief engineers may be a little skeptical. (*)
The key question: Is this lower power really enough? I have a friend who has planned and supervised over 25 DTV station constructions; he says (I hope I'm getting this right, GJS!) that in most cases the models are proving out roughly correct. However, there are confounding variables, of which I can think at the moment of two:
(1) Does the DTV transmitting antenna exactly duplicate the performance of the original analog antenna? (Unless the DTV uses the actual antenna used for the former analog transmitter, on the same channel, and it is left in exactly the same location, the answer is no.)
In fact, there are significant complications in duplicating the performance of the analog plant, some of them logistical and some of them due to aggrivating details in the FCC rules regarding the changeover.
(2) If the DTV is not going to move to the original analog channel, are there previously undiscovered anomalies in a given viewer's antenna system that are knocking out the DTV frequencies?
(*) The actual assignment of power is a little more complicated, in the common case where the DTV is in a different band than the ATV. There are three bands in US television, with different maximum powers: 2-6 (100KW), 7-13 (316 KW), and 14-(now)50 (5 MW.) Maximum allowable power can be further restricted for stations in certain areas with exceptionally high transmitting locations or substandard spacing to other stations on the same or adjacent channels.
I only watch TV for news and weather, especially severe weather warnings.
With analog, I get over 20 stations, 15 quite clear. With the digital junk, I get 6 on a good day.
My main problem is during wind and rain, all I get is “no signal” displayed on the tv.
This is totally unacceptable, and serves to endanger the public as it undermines weather warning systems.
The government has sold the public for a bill of goods once again. Actually this was mandated.. and we were told that the reception and video quality will be better.. its just better all around. Trust us.
It will be interesting to talk to my relatives in Rural areas who are over 50 miles from a nearest transmitter when the switch takes place...
We’re talking about two different auctions. The 700 mhz auction is related to the whole Nextel issue where their decision to co-locate antenna sites next to public safety sites resulted in interference to public safety systems. Thus, the frequency swap.
The intent of the DTV program is to get analog TV off its VHF frequencies so they can be sold off and used by others. The low end of VHF (down around 54 mhz) has some skip problems, the high end surrounds the current public safety VHF frequencies and should have similar issues to the current systems. Aircraft radio, FM radio, and much of public safety radio currently operates in the hole between channel 6 and channel 7.
With few exceptions, DTV will be in the UHF spectrum, between 14 and 50. Because you can put one HD signal and one or two SD signals on the same frequency, it should increase viewer options once it’s completely up and running. NBC’s Los Angeles DTV station, for example, runs an alternate channel that offers live breaking news coverage, frequently just raw footage from the helicopter. It’s also on the net at: http://www.knbc.com/newsraw/index.html
Ah, thanks for the technical information. I thought that might be the case. And I wasn't aware of the UHF only signal - I'll assume my antenna is a UHF/VHF combo.
If the Tyler station you’re talking about is KLTV...
Yes, that's the one.
I'm not saying this changeover is going to precipitate some sort of national calamity - but I do think it's going to be a huge problem. There's going to be a lot of money spent in addition to converter boxes.
I spoke with a neighbor this morning who has a professionally installed 40 foot triangular mast with a high-quality, motorized (I assume it's a UHF/VHF) antenna.
He's able to get most of the Dallas stations digital signals - but he does have the same problems with bad weather. He's in a better spot out in the open and I'm up near a treeline so that could be causing my problems too.
However, his rig is about $3K. Mine is about $400 max.
Once again Armsted, thanks for your technical explanation.
Here’s a site where you can plug in your address and get a plot of signal strengths and direction for the various DTV stations in your ‘hood’.
I agree, the change-over won’t be without a lot of controversy. Unfortunately, the fringe area viewers who were still watching free TV were very much in the numerical minority, so their interests were low on the FCC’s priority scale.
BUMP!
Ran across this link and thought I’d forward it.
http://www.rabbitears.info/market.php
It’s a list of all the TV markets and where their stations are going to end up once the digital transformation is complete. Essentially, most of the VHF’s in the channel 2 to 6 range are moving to UHF, while many in the 7 to 13 range are getting UHF frequencies at the moment so that they can begin running digital broadcasts, but will be moving back to their old VHF frequencies once the change-over comes in the Middle of February next year. Tyler is market 111, and KLTV is going to be one of those double swaps, beginning digital broadcasting on 10, but moving back to 7 once the change-over happens. 8 in Dallas and 11 in Fort Worth will be doing the same thing.
We’ve had a set-top box for a few months now....it sucks.
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