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Channel Surf
Guest
I am curious. How is the coverage area of the new digital TV channels compared to the old VHF channels 2-13? It is my understanding that HD FM only has about 60% the coverage of analog FM. Is it the same for TV?
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Channel Surf said:
HD FM operates within the same channel as the analog. To avoid interference, the digital signal must operate at reduced power - about 1% of the analog power.
Digital TV operates on completely different channels. In most cases digital stations are operating at full power and should have coverage very close to that of their analog signals.
There are some exceptions. Some stations are required to operate at reduced power (or use directional antennas) to avoid interference - there weren't quite enough channels to give everyone a fully clear second channel *and* remove channels 52-69 from service.
Other stations have chosen for economic reasons to operate at less than full power. Some of these are stations whose interim digital channel is above 51 - stations that will have to change channels in a year.
There will be a quite a reduction in channels available to many OTA viewers after the transition. It is true that digital channels operating at full power should cover the same areas as their previous analog channels, HOWEVER, because of interference issues, many are not going to be operating at full power, or will be directional. Here in Charlotte, three existing channels will have perminent reductions in coverage area. Two stations, WMYT and WJZY, now broadcast in analog with 5 million watts from almost 2000 ft. Both have their digital channels, 38 and 47 respectively, shortspaced to digital 38 and 47 in Columbia, SC, less than 100 miles away! WMYT will only be able to broadcast with 200,000 watts, and directional in 3 directions. They have begged the FCC to give them a different channel allocation, but have been turned down. Plus, in many areas, stations have AGREED to accept interferrence from other stations on the same or adjacent channels. The range of these stations will, of course, be reduced. Then there are stations in mountainous areas where UHF just can't penatrate those mountain ranges the way VHF did.
WYIN DT-17 Gary Indiana currently has reduced coverage, due to analog WLFI 18 in Lafayette Indiana & analog WNDU 16 South Bend Indiana. Their analog on 56 is non-directional at 1350kw. I don't know if the directional patterns will change once WLFI goes to 11 permanently or not. Had WYIN gone on top of the Sears Tower in Chicago, they would have had coverage similar to most Chicago area stations, but their null would have been toward Wisconsin to protect WPXE 55 Kenosha Wisconsin on analog 56, and DT-17 would have had to protect analog WVTV 18 Milwaukee. But WYIN withdrew their request due to high costs to be on the Sears Tower, and decided to stay at their site in Cedar Lake Indiana.
Why do I get the idea that a perfectly good system that has served us well for 60 years is being unnecessarrily destroyed. At the very least something that isn't broken is getting "fixed", and I can't help but ponder that corporate cable/satellite companies along with HDTV manufacturers are going to be the big winners here.
I think part of the reason is probably because there really aren't all that many people out there who have OTA reception anymore. And, I mean, why bother upgrading to a digital TV if you're not going to get cable? I mean, you still only get a limited number of channels compared to cable, so I think most people see it as pointless.
fortmill said:
Much of the interference will also be reduced. A lot of it comes from analog signals, which will be going away. In other cases, some of the stations causing the interference will be moving to new channels. And I'm sure quite a few stations will be increasing power considerably when they leave temporary assignments for their permanent channels.
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chuckydoll
Guest
ssetta said:
Ssetta is correct. Many DMAs have cable/satellite penetration at or over 90 percent.
As a point of reference the Netherlands was first to go all-DT in December 2006. The U.S. will merely be following the Dutch.
I think there will be some reassignments once we go all digital. Just like after the orginal freeze was lifted, channels got moved, like in Ohio and Rhode Island. I find it hard to believe we can have a channel 19 in Chicago AND Peroria. They are too close.
I can't watch WTTW Channel 11 (analog) since the digital channels started. It's awful. I have written and emailed to Channel 11, they never bothered to respond so they don't care or they can't do anything about it.
One thing HD FM is not high def. Just so people know
According to iBiquity Digital, holder of the HD Radio trademark, HD does not mean either hybrid digital or high definition, as some erroneously believe. It is hybrid digital. But that doesn't stop the stations from letting people THINK that if that is what they want to.
I can't watch WTTW Channel 11 (analog) since the digital channels started. It's awful. I have written and emailed to Channel 11, they never bothered to respond so they don't care or they can't do anything about it.
One thing HD FM is not high def. Just so people know
According to iBiquity Digital, holder of the HD Radio trademark, HD does not mean either hybrid digital or high definition, as some erroneously believe. It is hybrid digital. But that doesn't stop the stations from letting people THINK that if that is what they want to.
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Channel Surf
Guest
Out of curiousity...Why isn't it possible to go digital on VHF channels 2-13? And...what are the frequency allocations of the HDTV band going to be anyway? In the 1960s, I believe that analog TV was channels 2-84.
I know that some of the upper end UHF spectrum has been reduced over the years, although I have forgotten what it is down to now.
I know that some of the upper end UHF spectrum has been reduced over the years, although I have forgotten what it is down to now.
Channel Surf said:
It *is* possible, and quite a few stations have done or are doing it. (including the one I work for, whose digital signal is on channel 10)
There have been some serious noise problems with digital stations on channels 2-6, and stations are trying to avoid using those channels, though there are still some stations there.
The HDTV band is the same as the analog band, except that channels 52-69 will cease to be available when analog broadcasts cease. Analog channel 10 is 192-198MHz, and so is digital channel 10.
Analog TV occupied channels 2-83. Channels 70-83 were phased out in the 1970s and 1980s, turned over for cellular phone and trunked two-way use. Well before then, there were no full-power stations left on those channels, only low-power relay stations. ("translators") (strangely enough, last week the FCC approved the transfer of the licenses of two low-power relay stations on channels 70 and 73 in Virginia. I must presume these stations are operating under special temporary authority on some other channels - most TVs won't even receive channels above 69 anymore)
Channels 52-69 are going away with the digital transition.
w9wi said:
I though channels 2-6 were going away as well?
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It is possible, and many stations will have their final digital assignments in the VHF band, especially upper VHF (7 - 13). There are about 50-60 stations nationwide that have their final digital assignment in the low VHF band, (2 - 6). Low-VHF stations are more susceptible to interference, especially digital stations.Channel Surf said:
ssetta said:
In today's fragmented media environment, claiming to speak for "most people" is pointless.
First off, a sizeable minority of folks do still watch TV OTA -- and we're not necessarily poor, either. I see plenty of newish TV antennas in the middle class area that I live in. To the extent that a number of those antennas have gone up since the start of the decade, the pretty obvious driver for those installations was to receive digital OTA. Why might some people make this choice:
1. HDTV from the major networks will look at its best when received via digital OTA. Since cable and satellite retransmit what the local broadcasters offer, the image quality of the cable/satellite services cannot exceed that of the local broadcaster for ABC, CBS, NBC, Fox, The CW, etc. If the cable/satellite service chooses to recompress the broadcast signal, it may end up looking worse.
2. Depending on what types of programs you favor, some viewers will find that the majority of what they want to watch is available from their local broadcasters. This is, of course, a matter of personal preference which is why I made the comments about "most people", above.
3. In some areas, HD services are available OTA that are not available via all pay providers. This may occur because of bandwidth limitations at a cable system that prevent them from carrying all the local HD channels, or it may be because they have been unable to reach a retransmission consent deal with one or more local stations. As a result, viewers wishing to see all their local HD broadcasters will have to resort to an antenna.
4. It's free.
chuckydoll said:
And many have cable/satellite penetration that is much lower than 90%. For example, cable/satellite penetration in Boise, ID is just 69.8%. Dallas/Fort worth is at 78.2%, Minneapolis/Saint Paul at 77.1%, Salt Lake City at 75.7%, and Portland, OR at 81%.
There's lots of variation by region in these numbers. Interestingly, in a few markets, cable/satellite penetration has actually dropped over the past few years.
You can broadcast easily on low VHF with digital but the results are not as good because of the amount of interference. If you're old enough to remember Mom vacuuming when you were trying to watch TV, even with analog TV, the lower VHFs were always more effected by the old vacuum.
(Of course you didn't tell Mom her vacuuming was interfering with Woody Woodpecker or else YOU'D be doing the vacuuming )
(Of course you didn't tell Mom her vacuuming was interfering with Woody Woodpecker or else YOU'D be doing the vacuuming
)upstate29651 said:
Nope.
The original plan was to do away with VHF altogether, using channels 14-59. This plan was later amended (before the FCC ever acted on it) to read 7-51. When the final plan was laid, it was decided to keep channels 2-6.
I'm sure the swap 7-13 for 52-59 was seen as mutually beneficial by broadcasters and the new users who'd be buying the ex-TV spectrum at auction. 7-13 allows better coverage at lower power; 52-59 works better with smaller antennas. (any channel 7 antenna that could be stuffed inside a cellphone would be HORRIBLY inefficient!, not that a channel 59 antenna would be particularly good...)
I think some stations felt the even greater coverage afforded by channels 2-6 would be useful - they didn't yet realize what noise problems they'd face. And as it turns out 2-51 really isn't enough spectrum for the transition, 7-51 would have really caused some interference problems.
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