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Old 02-07-2012, 01:15 PM
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Jeffhs Jeffhs is offline
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Minimum screen size for HDTV?

I recently (as in last August) bought a 19-inch-class (18.5-inch diagonal) flat-screen HD television to replace my aging analog set. It works well on cable, but I notice that there is very little difference in picture quality on my HD FP between programs viewed on the local stations' standard definition channel and the HD channel. (The only HD programming available to me at this time on Time Warner Cable is on the Cleveland broadcast TV stations; the rest are carried on the cable in standard analog NTSC format.) Is there a minimum screen size one must have in an FP HDTV before the high-definition effect is noticeable, and would I be better off, my set being only just under 19 inches, just leaving my FP set on the standard-definition channel? I have Time-Warner analog cable service.
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Old 02-07-2012, 02:15 PM
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It might be set to downconvert HD to NTSC "standard defination", like a converter box does. There may be a menu option to change this, or else the display is physically limited to 480 lines. Though even an ordinary VGA computer monitor can do HD, and they come in sizes like your set.
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Old 02-15-2012, 01:32 AM
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Jeff-

If you have "analog cable", how are you getting the HD channels into your set? What connection(s) go into the set, and what mode(s) are used on it? At the minimum, I would expect that you have the cable itself going into the TV (no cable box), and to get HD channels you must have mixed digital/analog cable. Also in that case, the TV itself will have memorized a combination of analog NTSC channels and digital QAM channels. Is all of that true?

Or, do you have a cable box feeding the set? If you do, what connection does it use into the TV? The only connections that could give you an HD picture on ANY channels are the component (YPrPb) multi-color RCA jacks (five total plugs on each end between the cable box and the TV for sound and picture) or an HDMI cable from the box to the TV. Let me know. I watch some HDTV on this laptop computer that has a 12-inch screen, and the difference from HD down to standard definition is easy to see.
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Old 02-15-2012, 11:55 AM
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Quote:
Originally Posted by ChrisW6ATV View Post
Jeff-

If you have "analog cable", how are you getting the HD channels into your set? What connection(s) go into the set, and what mode(s) are used on it? At the minimum, I would expect that you have the cable itself going into the TV (no cable box), and to get HD channels you must have mixed digital/analog cable. Also in that case, the TV itself will have memorized a combination of analog NTSC channels and digital QAM channels. Is all of that true?

Or, do you have a cable box feeding the set? If you do, what connection does it use into the TV? The only connections that could give you an HD picture on ANY channels are the component (YPrPb) multi-color RCA jacks (five total plugs on each end between the cable box and the TV for sound and picture) or an HDMI cable from the box to the TV. Let me know. I watch some HDTV on this laptop computer that has a 12-inch screen, and the difference from HD down to standard definition is easy to see.
Chris -

Yes, it's true. My cable connects directly to the TV (well, through my DVD's RF modulator, to which the cable actually connects, then to the VCR, then to the TV's antenna port). I do not have a cable box. My TV will scan for analog channels first, then digital/clear-QAM, when I do a channel scan, so the cable is carrying both analog and clear-QAM digital signals.

My set does have a six-jack panel on the back for the video connections you mention, but of course I am not using them since the cable connects directly to the TV via the RF antenna port.

Since I am obviously not getting an HD picture with the arrangement I described (direct cable connection to the set), does it make any difference at all whether I watch the HD or SD feeds of the local TV stations in my area? At least one channel here (WKYC-TV NBC channel 3) has both SD and HD feeds, while the other two stations (major network affiliates) have only HD feeds. The cable channels themselves (ESPN, CNN, AMC/TCM, et al. -- 64 channels in total for now) are analog NTSC feeds only. The other fifty or so channels are digital ATSC. I say "for now" in reference to the analog feeds because several analog cable channels have already been moved by TW to the digital tier, and the day is coming when the rest of them will wind up there as well. I can see a day when my TV will find absolutely nothing when its tuner scans for analog channels, but it will find well over one hundred digital ATSC ones -- the fifty channels that are currently NTSC analog will have been moved to digital at that time.

I guess the only reason I got a flat-screen TV last August was to avoid losing channels (and to avoid having to pay for a cable box) if and when the cable goes completely digital some time this year; however, Time Warner in my area claims to be 100 percent digital already, which is confusing. There are obviously still 64 analog NTSC channels on the cable now. I don't know if I will lose them at the end of this month (leaving me with only the DTV broadcast channels), even though my TV has (as do all flat sets made since 2007) an ATSC/NTSC/8VSB/clear-QAM tuner. With this type of tuner in my set, however, I wouldn't expect to lose anything except scrambled movie channels and pay-per-view (PPV) channels; I do not want or need movie channels anyway, since I have a DVD player.
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Last edited by Jeffhs; 02-15-2012 at 12:02 PM.
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  #5  
Old 02-15-2012, 02:11 PM
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I have two Samsung 19" HDTV's, and the difference between HD and SD is very obvious, even on this size a set. I suspect the tuner in your DVD recorder converts HD to SD, as I know of no DVD recorders that can record in HD off the air (copyright concerns). If you're passing the signal through a VCR on the way to the TV, then it definitely is a SD signal, as no VCR's have the correct inputs to accept or pass through an HD signal.

I have analog cable, and the service converts the HD channels to SD, which I use for my SD sets. For true HD reception, I rely on over the air signals through an antenna for my HDTV's.
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Old 02-15-2012, 08:34 PM
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I called Time Warner Cable this afternoon and found that their systems, including the one serving my area, are 100 percent digital. My HDTV will still pick up some 64 analog channels as well as 50 digital ones; when I mentioned this to the customer service representative with whom I spoke, she told me she has no idea why NTSC analog channels are still on the cable in the first place, since the service is fully digital. I also asked if there was a way I could upgrade my cable service to the next level above standard service (the level of service I have now) without using a cable box; the answer was no -- a cable box is in fact necessary for all levels of service above standard cable. Why on earth would I need a cable box at all with an HDTV? The tuners in these sets are, or at least should be, capable of receiving well over 1000 channels without a box.

What baffles me is this: why, if Time Warner Cable's systems carry 100 percent digital signals with no analog whatsoever, am I still receiving analog NTSC cable channels as well as digital? I think that service representative wasn't giving me straight answers (or even the correct ones) to my questions.

I remember reading online somewhere, don't remember where, that the customer service representatives at Time Warner Cable (and likely most other cable operators as well) don't know much, if anything at all, about the technical end of the cable system, and will often give customers seriously incorrect answers to questions regarding such. If this is indeed the case, where does someone like myself go to get absolutely correct answers to technical questions such as the ones I mentioned?

I did not realize that all signals on my cable are SD if they can pass through a VCR on the way to the television, as in my system. I do realize, however, that there are no such things as "HD" VCRs; there legally could not have been such machines (that could actually record television programs in high definition) available for sale to the public, due to legal concerns over copyrights. My 2002-model Panasonic Omnivision four-head VCR cannot record anything on channels between the regular ones (digital subchannels), such as, in my area, channels 3.1, 5.1, 8.1, 8.2, 19.1, 19.2, 25.1, 25.3, 43.2, and 43.3, since it does not have an ATSC tuner; no VCR I am aware of ever did, as these machines were well on their way out in favor of DVDs by the time HDTV arrived.

New standalone VCRs are no longer available; the only way to replace an old one these days is to get a combo VHS/DVD player. However, these combo units will only play back recorded tapes and DVDs, since they do not have RF tuners. The only way to record anything (on video tape, not DVD) with these units, at least for now, is to feed a signal from a cable box, or straight from the cable, into a line-input jack on the rear apron of the machine. Who knows how long that functionality will continue to be available on VHS/DVD players in this day and age of DRM (digital rights management), copyright laws, and other things designed to soundly thwart copying of commercially-made DVDs? The next step may well be to eliminate altogether the line inputs on DVD/VHS combos, if such isn't standard procedure already.
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  #7  
Old 02-15-2012, 10:26 PM
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ChrisW6ATV ChrisW6ATV is offline
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Jeff-

Since you said your cable goes into a modulator for a DVD player, then out of that into a VCR, then out of THAT to the TV, the first thing is to turn off the power to the modulator, DVD player, and VCR, to make sure you are not getting anything from them. I do not otherwise know why the HD channels do not appear better than their SD equivalents. (All of those are among the "clear QAM" digital cable ones, right?)
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  #8  
Old 02-15-2012, 11:25 PM
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Quote:
Originally Posted by ChrisW6ATV View Post
Jeff-

Since you said your cable goes into a modulator for a DVD player, then out of that into a VCR, then out of THAT to the TV, the first thing is to turn off the power to the modulator, DVD player, and VCR, to make sure you are not getting anything from them. I do not otherwise know why the HD channels do not appear better than their SD equivalents. (All of those are among the "clear QAM" digital cable ones, right?)

Chris -

I neglected to note in my last post that I do in fact notice a difference, albeit slight, between HD and SD television programming on my cable, although one must look very carefully to spot the differences. One I notice for certain is that the network logos on all three commercial networks (and PBS) are slightly smaller in HD than they are in standard definition, but other than that I haven't noticed much else between HD and SD. However, when I called Time-Warner Cable and asked about this issue, I was told that the kind of cable connection I have (cable directly connected to the TV) cannot and will not provide high-definition reception, even with an HDTV. The only way I can possibly get HD is to upgrade to the next higher level of service, for which I would need a cable box. Time Warner offers this level of service (and, I assume, the next level above that) in high definition; they do not charge extra for HD service, but the cable box rental is $8.50 per month. However, I will not upgrade to that level of service for one and only one reason: because I do not care to have a cable box on my HDTV, which is already supposed to be set up to receive most cable and broadcast channels with its 4-mode tuner (NTSC, ATSC, 8VSB, clear QAM).

I don't know why I would still need a cable box for HD, if my TV already has a built-in tuner that can receive just about any kind of TV signal on cable today. Is there some kind of signal processing required for HD television signals that only an external cable box can perform? For that matter, will there ever be an HDTV that will process literally any signal format on any cable system in the US, without the need for a cable box? With HDTV technology changing as fast as it is these days, it wouldn't surprise me if such an HDTV is under development even as I write this, and such a set could be available in perhaps five years or even less.
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Last edited by Jeffhs; 02-15-2012 at 11:32 PM.
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  #9  
Old 02-15-2012, 11:59 PM
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ChrisW6ATV ChrisW6ATV is offline
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Jeff-

The limitations on what channels are available without a cable box are entirely cable company choices, not technological issues at all. In fact, most cable systems encrypt almost ALL digital channels, not just the movie ones. Usually, the only ones in clear QAM are in fact the broadcast networks (and maybe shopping channels or local-access-type channels), because the FCC does not allow the OTA channels to be encrypted.

Since you do see some difference in the HD channels, maybe it is just a matter of one person's perception versus another. I know on a set that size, you will have to be not more than maybe three feet away to see the difference in detail of a good HD signal. Also, because you are on cable, it is quite likely that Time Warner's HD signals are not as good as the true broadcast signals. (Cable companies do re-encode the signals from the over-the-air 8VSB (ATSC) into QAM, and they may intentionally limit the signal quality to allow more channels on the cable system.)
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