Earlier today I came into posession of a HDTV tuner card for my computer. This card can receive both Analog and Digital signals. I have been playing with it for awhile and I want to share my experience.

HOOKING UP AN ANTENNA:

After I got the card installed into my computer, I hooked the simpliest and crudest antenna to the card, a 3 foot long piece of wire. The piece of wire is my desperate antenna, normally used to bring in a TV signal when nothing else is available. Normally I can bring in a few watchable analog stations.

The simple wire antenna failed to bring in any digital signals.

My next step was to lengthen the wire. This did the trick. I now can bring in several digital channels.


WATCHING AND CHANNEL CHANGING:

The picture quality on High definition channels is great! I can make out more details on people's faces, read smaller text, and the framerate is smoother then analog NTSC. Standard definition digital looks kinda crappy though. There are compression artifacts, and the detail isn't nowhere near as fine, but the framerate is still smooth.

Channel changing is fast. I have heard complaints here about digital tuners taking a second or two to change channels. The tuner in my TV card changes at a comparable speed to an analog tuner.

WEAK SIGNALS:

My software includes a signal strength meter, which I like VERY much! I used to guess at analog signal strength by how fuzzy the picture was. This strength meter tells me exactly how strong the signal is.

When signal strength drops to below 50% CORRECTION: 70%, the picture starts to go out. However, it does not take a second or two to come back. It comes right back right away once the signal is strong enough. There's no blockiness or artifacts. The picture and sound just stop, then come right back once the signal strength improves. A good antenna is necessery.

OVERALL JUDGEMENT: Over the air digital TV is not too bad. I can bring in local stations with a signal strength of 85 to 90% with a piece of long wire, in a basement no less. There is no ghosting or fuzziness, and no interference. Picture quality is certainly better for HD, but somewhat worse for SD. All in all, I don't think there will be a revolt after the 2009 switchover.

I will probably be putting a roof antenna up to see if I can bring in more channels in the future.

I found that an old fashioned UHF hoop antenna works well for HDTV. All the HD in this town (NYC) are in teh UHF band. This is on an RCA ATSC/SAT receiver set top box, and also on a Samsung ATSC ATSC box. But I'm line of sight 14 miles from the Empire State Building, where the signals come from.

Working with an indoor antenna that includes a UHF loop.

I have one drawback to add to my HDTV experience. My TV card takes FOREVER to rescan for new channels! I hope HDTV's aren't like this!

MRX... Since we are in the same broadcast area, can you tell me what channels you bring in?

Are any Canadian stations broadcasting in digital yet? (9 & 32) I actually care more about those since the only OTA-programing I really care about is Coronation Street on 9, and Saturday Night Movies on 32.

Carmine:

So far I have picked up PBS HD, CBS HD, Channel 20 SD, WADL channel 38 SD and WKBD 50 SD.

Still working out antenna placement. I currently do not have an outdoor antenna. (would REALLY like one, but...)

A bit of an update: A weird issue has popped up.

Earlier today I was watching a couple stations with maybe 65% signal strength, and they didn't hiccup one bit. Now stations with 75 to 80% signal strength are hiccuping alot.

Perhaps there IS some form of interference. These stations seem to be in the lower UHF band (Around 300 Mhz). maybe something in my house is generating an RF field that's screwing with reception...

So far I have picked up PBS HD, CBS HD, Channel 20 SD, WADL channel 38 SD and WKBD 50 SD.



Excuse my lack of knowledge on ATSC, but I guess I'll have to learn eventually...

So you are getting PBS ("normally" 56)... What channel is it digitally? Do digital channels use a number? I hope it's not 0110111001000, because that's damn hard to remember. Same question for CBS (62).

So low-budget channels 20, 38 and 50 are only broadcasting in standard-def? What digital "number" do they appear on?

Why no reception of FOX, NBC and ABC (2,4,7)?

Sorry for the question ambush, but you are the FIRST person I know locally who has bothered with digital nonsense. :D

Over-the-air HDTV is the way to go. There are all sorts of different channels out there and the "regular" stations often have two or three secondary channels for music videos and other programming. My local PBS station has one sub-channel for documentaries and another for panel discussions, etc. in addition the the regular channel.
We watched FOX HDTV SuperBowl on the projector at 1080i - you could see everyone's pimples.
I have been using an off-air receiver for about three years now. I see absolutely no need for cable or other pay service (although Discovery, History and the Tour de France would be nice - but just not worth the $$$)
DH

Over-the-air HDTV is the way to go. There are all sorts of different channels out there and the "regular" stations often have two or three secondary channels for music videos and other programming. My local PBS station has one sub-channel for documentaries and another for panel discussions, etc. in addition the the regular channel.
We watched FOX HDTV SuperBowl on the projector at 1080i - you could see everyone's pimples.
I have been using an off-air receiver for about three years now. I see absolutely no need for cable or other pay service (although Discovery, History and the Tour de France would be nice - but just not worth the $$$)
DH

Yeah, I know our local NBC affiliate here in Pittsburgh also broadcasts the Retro TV network, I once joked that the knob on my ATSC tuner would be glued to that channel. B-)

Excuse my lack of knowledge on ATSC, but I guess I'll have to learn eventually...

So you are getting PBS ("normally" 56)... What channel is it digitally? Do digital channels use a number? I hope it's not 0110111001000, because that's damn hard to remember. Same question for CBS (62).

So low-budget channels 20, 38 and 50 are only broadcasting in standard-def? What digital "number" do they appear on?

Why no reception of FOX, NBC and ABC (2,4,7)?

Sorry for the question ambush, but you are the FIRST person I know locally who has bothered with digital nonsense. :D

No prob:

First off: Why no reception of NBC, ABC or FOX? Well, the computer that my TV card is in, is in a basement that is notorious for PISS POOR TV reception. All I currently have available to me are indoor antennas. I think I need a good outdoor antenna and a good 75 feet of coax cable.

As for channel numbers... I'm still trying to figure those out. For example, my TV card labels digital channels as "12XX" AKA: 1201, 1215, etc. HOWEVER I do know one of the digital PBS stations (there's more then one, same with WADL) calls itself channel 56.1 Also, the standard def Channel 20 station calls itself by its analog name (can't think of what it is)

I will conduct more tests and try to rig up a better antenna. I will also try hooking it to the cable system and see if I pull in any digital channels.

Also, the standard def Channel 20 station calls itself by its analog name (can't think of what it is)


http://www.tv20detroit.com/

It's called "mytv", or WMYD. I can't think of the last time I watched it. :puke:

Oh wait, it was 1989 when it was called WXON and they showed cool movies at night and Addams Family/Beaver/Twilight Zone in the afternoon. :cry:

WYMD Yeah.

I"m frustrated because my TV card scans for new channels, and won't save channels it's already found! I've lost all the HD channels I had earlier today! This isn't Digital TV's fault, but not knowing the channel numbers is contributing to my headaches right now.

Oh, and one improvement I see in Digital TV's future is something similar to the skip protection found on CD players, where the TV will buffer a few seconds of video to compensate for a poor signal...

EDIT:

Okay, I know that Cw50 is channel 14 on my tuner channel, but it's also called 50.1 WMYD TV 20 seems to be channel 21, but is also called 20.1. There's a 20.2 channel that seems to be on the same channel...???

My TV card software is being very cryptic about information such as channel numbers, so I can't give any better info.

EDIT 2: I strongly suspect that the digital TV transmitters are located in different areas of Detriot then their analog counterparts. This is suspected because on an antenna I rigged up, certain analog channels come in almost perfectly, but their digital counterparts won't come in at all. Rotating the antenna allows the digital channels to return, with so so analog...

Your computer based receiver card and software may do some stupid things with channel numbers. A regular digital TV should be designed to show the channel number of the analog signal plus a secondary number after a decimal point or dash. Thus, analog channel 20 (which is really on RF channel 20!) should show as simply "20" while all the digital signals put out by that station (whcih are on a different RF channel) will show as 20.1, 20.2, 20.3, etc. One warning - this does depend on the station sending out the correct designation, but they should all straightened out on this by now! The broadcasters (at least the ones who were paying attention) insisted on this arrangement because their local programming is usually branded by their analog channel number, e.g. "TV7 news at 11:00."

An exception to this may occur during intial setup - the set may use the actual RF channel number until it has acquired the "virtual channel number" form the DTV broadcast.

Regarding indoor antennas, the loop is not so great. There is a small log periodic called the "Silver Sensor" and some other variations on it that is pretty good, and surprisingly, the old "dual bow tie and reflector" set top is not too terrible either for UHF. Indoor low VHF can still be a problem for digital as it has been for analog, but in your case, if all the digital stations are UHF, no need to worry. An amplified indoor antenna may or may not help - unfortunately their designs seem to vary all over the place.

Oh ho my TV card software is doing some stupid stuff all right...

I pulled in 3 HDTV stations with a small outdoor antenna I rigged up. Signal strength is at 100% I rotate the antenna to try to capture more channels, and the channels i do have still come in at 90-95%. I rescan, and the software finds NOTHING!!! It should have at the very least found those three channels again!

UPDATE: I think HDTV stations switch of their transmitters at night time. Today I scanned for channels, using the exact same antenna setup I had last night, and I've found:

WDIV-HD
WDIV-SD
WWJ-HD
WTVS-HD
WTVS-SD
WTVSSD2
WXYZ-HD
WXYZ-SD
WADL-DT
WMYD-HD
WCSN-TV
and WKBD-HD

Lotsa channels today. Interesting about WWJ, as that's a radio station...

MRX37-

Thank you for your fair and balanced descriptions of your digital TV reception experiences.

One big reason that an NTSC signal can be strong but its ATSC equivalent weak is that many digital stations are still using lower power (sometimes much lower) than their analog counterparts. In a way, we cannot blame them for not wanting to have a double power bill. This should change next year when the NTSC stations go off the air, and is one of the less-known benefits of the analog shutdown.

It used to be common for stations to not have their digital signals on the air full-time, and also for them to just go away for days or more at a time when there were antenna problems (imagine NTSC stations getting away with that!), but it is rare now.

Chris: Signal strength is not the issue. My TV card software is. The signals are out there nice and strong. I have most of the bugs with my new TV card ironed out now, and I have a few things to add to my experience of Digital TV:

As I stated, a digital High definition channel has excellant quality and a smooth framerate. I can see no juddering. Motion is nice and smooth. However, even on the CBS sports HD channel, I do notice some compression artifacts in the video, especally when there's fast motion. I am viewing this on a 19" flat screen CRT computer monitor, which is a pretty small screen size for HDTV. I think the artifacts may be more noticable on the 50+ inch displays. I may be wrong, as I have never looked at a 50+ inch display too closely.

The colors look great. Reds, greens, and blues look like they're supposed to. The picture doesn't seem to be oversaturated or too dark/too light, etc. Quality on both PBS HD and CBS HD seems to be equal. sound is also great. It's like I'm watching a DVD. I think if you see an HDTV where the colors look too cold or somehow not right, it may be due to the TV itself and not to the signal. I am hoping that after the switchover, stations will have more bandwidth and can improve the quality further.

Standard definition channels are getting only a small piece of the bandwidth pie. Their framerate is still smoother then analog NTSC, but compression artifacts are more noticable, and on WDIV, the audio sounds like an MP3 that's undergone too much compression. Colors don't look as good as they do on the HD channels. For standard def, Analog is still better. I don't know if this will change after the switchover, but that's how it stands now.

I've had a digital receiver for years, a Samsung, and I have found reception as variable as the wind. Night time reception is always better, except sometimes. Digital stations you got last night are always available the next night, except sometimes. Stations you received at night are always available during the days, except sometimes. Reception in town is better than suburban reception with a roof antenna, except sometimes.

I hope you are seeing the trend here. My receiver, when picking up a station, gave a quality picture with a strong signal but there were times when signal strength was strong yet there was nothing but a black screen. With my high powered roof antenna and 20db+ signal amplifier I could get stations all over the central part of Florida, except sometimes. The receiver would scan and memorize stations only to forget them tomorrow and re remember them the day after. This would be irregardless of whether the station was watchable or not, except sometimes.

I think anyone who is limited to watching OATV is going to be very upset and disappointed in what they can watch and when. It will end up being like the old days when all you could get was one or two stations. I have that receiver at work now in the heart of Orlando and at present it is able to watch one or two digital stations at best, except sometimes, and that is with a roof antenna at 30' off the ground. The receiver was a top of the line Samsung from a little over two years ago. It was so undependable that my wife refused to use it. I don't blame her. Receivers will develop and get better with time but I doubt that any of them are much better than the one I have. Digital TV is going to be a flop for the poor and non technical and may be a flop for the rest of us too. I for one am unimpressed, except sometimes. If it is true that the stations are running at less than full power, then maybe this will all change.

I, on the other hand, have exactly the opposite experience. My over the air digital seems to be stable as a rock. It is far better than the analog. I wonder if there isn't a problem with a connection or with the antenna amp?
I use an amp as well as a motorized antenna rotar - but they were there before I went digital. And I live in area with mountains, too.

Also, I've heard that the early Samsung stuff had some problems similar to what you are having - mostly heat related. That's one reason I went with a different brand.

DH

I don't understand complaints about NTSC frame-rate? Unless this has something to do with watching TV on a computer monitor, which I have never bothered with.

On a regular TV, I've never noticed frame rate problems...?

I've had a digital receiver for years, a Samsung, and I have found reception as variable as the wind. Night time reception is always better, except sometimes. Digital stations you got last night are always available the next night, except sometimes. Stations you received at night are always available during the days, except sometimes. Reception in town is better than suburban reception with a roof antenna, except sometimes.

I hope you are seeing the trend here. My receiver, when picking up a station, gave a quality picture with a strong signal but there were times when signal strength was strong yet there was nothing but a black screen. With my high powered roof antenna and 20db+ signal amplifier I could get stations all over the central part of Florida, except sometimes. The receiver would scan and memorize stations only to forget them tomorrow and re remember them the day after. This would be irregardless of whether the station was watchable or not, except sometimes.

I think anyone who is limited to watching OATV is going to be very upset and disappointed in what they can watch and when. It will end up being like the old days when all you could get was one or two stations. I have that receiver at work now in the heart of Orlando and at present it is able to watch one or two digital stations at best, except sometimes, and that is with a roof antenna at 30' off the ground. The receiver was a top of the line Samsung from a little over two years ago. It was so undependable that my wife refused to use it. I don't blame her. Receivers will develop and get better with time but I doubt that any of them are much better than the one I have. Digital TV is going to be a flop for the poor and non technical and may be a flop for the rest of us too. I for one am unimpressed, except sometimes. If it is true that the stations are running at less than full power, then maybe this will all change.


Well, My current setup is a small homemade antenna that stands about 6 feet off the ground. This is connected to about 50 feet of coax cable, spliced together with coax connectors. It has been raining today, and has been windy and overcast.

I have not had one hiccup on any of the channels today.

Perhaps my TV card has a better tuner then your receiver, perhaps the stations in my area are broadcasting at full power. Either way, signal dropping hasn't happened today.

I'm not convinced that Digital TV will flop. It's not a silver bullet, but so far it's not as nightmarish as I expected. Improvements do need to be made, and I think they will be made in time.

I hope it was purely an issue with the Samsung receiver. I applied to the FCC website for two $40 coupons, which I have yet to receive, and plan on buying two receivers when they become available. I sincerely doubt the claim that they will cost $70 or less as the government is claiming. I also foresee a huge backlog of demand for receivers that won't be met till well after the January, 2009 deadline. I would love to see all this work the way it is planned but I have real doubts. I'll wait and see. :lurk:

I don't understand complaints about NTSC frame-rate? Unless this has something to do with watching TV on a computer monitor, which I have never bothered with.

On a regular TV, I've never noticed frame rate problems...?

NTSC framerate is 29.97 FPS as far as I know. Very smooth, but ATSC seems to have a smoother framerate. Maybe 60 FPS. I'm not sure. The framerate just seems to be smoother.

Perhaps it has to do with the deinterlacing my TV card does for analog. i don't know.

EDIT: To clarify: I've been studying things like arms swinging when people are walking, motion while a car or other vehicle is driving, golf clubs swinging, and the HD channels seem to have more fluid motion then analog.

Also, WKBD 50 had an HD channel, but they seem to mostly have analog programming, and the motion is a bit less fluid.

I notice framerates because when I install a new game or videocard on my computer, I turn on the framerate counter and examine the movements. I start to notice juddering at around 30 FPS. DVD has this juddering as well. It seems to be gone for some of the ATSC channels I'm receiving.

I just watched Channel 7 action news in HD. Interestingly they talked about the 2009 switchover. They said basiclly what I've heard. You'll need a converter box, and the government is giving away coupons, etc.

More interesting is that some of the news footage is 4x3 with computer decals on the sides of the 16x9 video. Also, some of the 16x9 news footage was rather low resolution... Kinda disappointing as this is supposed to be HDTV...

Oh, and the channel logo was on the bottom of the screen, but it's pushed over far enough to fit on a 4x3 screen, despite the logo saying HD under it.

720p channels, and SD (480p) channels are 60 frames per second, but 1080i is 30 FPA interlaced, just like NTSC. A lot of tuner cards to a really bad job of de-interlacing, so that's probably the problem.

I was playing with a tuner card recently and it allowed you to see everything that it was receiving on a channel. Most channels were using a good part of their bandwidth for SD multicast channels. Some channels were not even using the full 19 Mbits for video. Only one channel was using the full bandwidth for a single HD feed.

720p channels, and SD (480p) channels are 60 frames per second, but 1080i is 30 FPA interlaced, just like NTSC. A lot of tuner cards to a really bad job of de-interlacing, so that's probably the problem.


I KNEW the motion on the sports HD channel was too fluid to be 30 FPS. My card actually does a good job of deinterlacing, it's just that I can notice a difference between 30 FPS and 60 FPS.

We are on DVB-T in Australia.

I've played around with a few HDTV STBs that I found recently. They are starting to hit the curb fairly regularly around here lately in some areas.

When it's working right the picture is good, but when it glitches it gets annoying.

The most frustrating problem I have found is that they all ignore the aspect ratio setting. The aspect ratio will change from program to program (and from ad to ad sometimes) regardless of what the box is set to.

This leads to 4:3 content being shown with black bars on the sides when viewing on the 4:3 set even though the box is set to 4:3 fullscreen. I can live with letterbox or center cut on 16:9 content, but why do they need to mess with existing 4:3 content?

Sometimes the picture appears with a black border on all four sides, so even those with 16:9 sets lose!

So far every box I've tried has been made by DGTEC, so I hope this is just a problem with their boxes.

We are on DVB-T in Australia.

I've played around with a few HDTV STBs that I found recently. They are starting to hit the curb fairly regularly around here lately in some areas.

When it's working right the picture is good, but when it glitches it gets annoying.

The most frustrating problem I have found is that they all ignore the aspect ratio setting. The aspect ratio will change from program to program (and from ad to ad sometimes) regardless of what the box is set to.

This leads to 4:3 content being shown with black bars on the sides when viewing on the 4:3 set even though the box is set to 4:3 fullscreen. I can live with letterbox or center cut on 16:9 content, but why do they need to mess with existing 4:3 content?

Sometimes the picture appears with a black border on all four sides, so even those with 16:9 sets lose!

So far every box I've tried has been made by DGTEC, so I hope this is just a problem with their boxes.


No, it isn't .... I have some Panasonic DMR-EZ27 dvd recorders with the atsc tuners, and run an s-video & rca l/r audio into an older 4:3 tv and I get those double letterboxed pictures all the time, It has been bad enough that at times that I estimated that the vertical coverage of the screen was 1/3, in otherwords, 1/3 black, 1/3 pix & 1/3 black from top to bottom.

I just watched Channel 7 action news in HD. Interestingly they talked about the 2009 switchover. They said basiclly what I've heard. You'll need a converter box, and the government is giving away coupons, etc.

I forget which channel I was watching, but they all have been talking about digital switchover lately during their nightly 2 hour block of info-tainment (I mean "news"). I suppose this is because the date is now less than a year away.

Anyways, they are cross-promoting with a local appliance chain (ABC) and they cutaway to a display at the store that showed two TV screens behind a piece of plywood labeled "digital" and "analog". Guess what happened? The digital screen froze, then pixelated! :lmao:

Needless to say, they cut back real quick while acting like that just didn't happen!

The most frustrating problem I have found is that they all ignore the aspect ratio setting. The aspect ratio will change from program to program (and from ad to ad sometimes) regardless of what the box is set to.

This leads to 4:3 content being shown with black bars on the sides when viewing on the 4:3 set even though the box is set to 4:3 fullscreen. I can live with letterbox or center cut on 16:9 content, but why do they need to mess with existing 4:3 content?

Sometimes the picture appears with a black border on all four sides, so even

Ah yes. I have come across this as well. The program may be in 16x9, but the commercials are 4x3. Sometimes my screen is surrounded by a black border on all sides of the video.

That is one glitch they need to work out.


I forget which channel I was watching, but they all have been talking about digital switchover lately during their nightly 2 hour block of info-tainment (I mean "news"). I suppose this is because the date is now less than a year away.

Anyways, they are cross-promoting with a local appliance chain (ABC) and they cutaway to a display at the store that showed two TV screens behind a piece of plywood labeled "digital" and "analog". Guess what happened? The digital screen froze, then pixelated!

Needless to say, they cut back real quick while acting like that just didn't happen!


They didn't talk about the switchover very much on 7 action news last night... maybe cos I was watching the HD version. They didn't show an HDTV screen freezing and pixelating, though I saw some of that yesterday.

For like maybe one or two frames, PBS-HD had a couple pixelated squares in the video. It only happened once, and wasn't due to weak signal. Maybe a station error or something.

I'm building a better antenna to replace the small outdoor antenna I currently have. Once I get it rigged up, I'll hunt for new channels.

Ah yes. I have come across this as well. The program may be in 16x9, but the commercials are 4x3. Sometimes my screen is surrounded by a black border on all sides of the video.

That is one glitch they need to work out.


That is annoying. I had thought that perhaps a TV tuner card would allow for greater flexibility in the this respect as the decoding is done in software. If even they suffer from aspect ratio glitches then it does suggest that the stations themselves are hard encoding content in the (sometimes wrong) aspect ratio.

It may be a side effect of the source video being reencoded several times at points in the distribution chain. I have seen a similar effect when a video file is converted from one format to another on a PC prior to burning to DVD.

I guess I'll just stick to analog and SD digital for now, it's not like I watch that much broadcast TV anyway.

That's "postage stamping." It's a problem for the industry to work out...has nothing to do with your gear. It's a side effect of transmitting a letterboxed 4:3 signal in a 16:9 ratio. SMPTE has a study group working on this one.

One other weird side effect I notice sometimes, kinda the opposite of this, is that there are spots done in 16:9 that get smushed back to 4:3 so everything looks painfully narrow. When spots like this air at work they tell me that's how they're delivered to us. So apparently there are some post houses that also need skoolin' on this stuff.

That's "postage stamping." It's a problem for the industry to work out...has nothing to do with your gear. It's a side effect of transmitting a letterboxed 4:3 signal in a 16:9 ratio. SMPTE has a study group working on this one.



Actually, it has been worked out and the means to transmit it was just recently standardized as "active format description". However, it will take a while for everyone to get it into their encoders, and for all the receiver manufacturers to get it into the receivers; and some video streams that are in the can may never be corrected. If a station follows good practices, the problem should not appear in the main program even on older digital receivers, but will still pop up occasionally on commercials, etc.

Some shows are taking advantage of the extra sides on a 16x9 screen, and poke fun at the 4x3 format. On Wheel of Fortune, I saw a sign in the corner of the screen that said "HD zone ahead" or something like that. This sign is not visible on the 4x3 aspect ratio to my knowledge.

I built a better antenna, and now I'm getting all our local channels in HD. 2,4,7,38,50, 56, and 62. No canadian stations yet...

The digital channel numbers are something like 2.1, 7.1 and 56.1, but according to the physical channel number, Channel 2 is actually channel 58, channel 4 is channel 45, and channel 50 is channel 14. Most of the other channels are close to their analog couinterparts, in channel number anyway...

The whle aspect ration thing is a real disaster. Leaving it up to the viewer was a big mistake. It should have been made fully automatic right from the start of 16:9 sets. Almost every wide screen TV I see is set wrong. Most people don't notice when it's wrong and don't understand how to set it up correctly. My mom was surprised when I told her that everyone isn't supposed to look fat on a wide screen TV!

You can query the FCC database to find out what TV signals are licensed to be seen in your town http://www.fcc.gov/mb/audio/tvq.html
If you live in the middle of nowhere, you can enter latitude and longitute.

It will tell what channels the digital channels are really on.

You can query the FCC database to find out what TV signals are licensed to be seen in your town http://www.fcc.gov/mb/audio/tvq.html
If you live in the middle of nowhere, you can enter latitude and longitute.

It will tell what channels the digital channels are really on.

That helps quite a bit.

You wouldn't happen to know the Canadian equivelant, would ya?

Some shows are taking advantage of the extra sides on a 16x9 screen, and poke fun at the 4x3 format. On Wheel of Fortune, I saw a sign in the corner of the screen that said "HD zone ahead" or something like that. This sign is not visible on the 4x3 aspect ratio to my knowledge.
This is what I am looking forward to, more TV directors actually composing for the 16:9 screens. Probably not a single HD show today does that, since the majority of viewers are still using 4:3 displays. There are, or have been, a few shows (such as Conan O'Brien's show) that letterbox their SD broadcasts and therefore may take advantage of the 16:9 format.

Football games in HD are starting to make use of the wide screen; it is nice to see both wide receivers/cornerbacks and the offensive and defensive lines on screen all at once, while still being able to read the numbers on all the visible players' uniforms.

An update: I have been looking for Canadian digital TV stations, and have been puzzling as to why I can't find any. I now know why. Apparently stations such as CBET in Windsor aren't broadcasting in digital yet. Canada's analog cutoff isn't until 2011, so I guess that's a reason for me to keep my Analog system going after 2009.

The whle aspect ration thing is a real disaster. Leaving it up to the viewer was a big mistake. It should have been made fully automatic right from the start of 16:9 sets. Almost every wide screen TV I see is set wrong. Most people don't notice when it's wrong and don't understand how to set it up correctly. My mom was surprised when I told her that everyone isn't supposed to look fat on a wide screen TV!

Even tho' my set has options for different screen sizes on 1 16x9 screen, non of them can really do a 4x3 image very well,for all non HD sources.For HD,it locks to the "full" mode and that cannot be changed.This is what I use exclusively now with digital cable.

But,just like the old saying for NTSC, the images that are displayed on the HD channels are so inconsistant,it really makes you wonder what the engineers are smoking.On some channels,all that's being done is blowing up a 4x3 image to fill a 1.78:1 screen.Not true HD by any stretch..they're just passing it as such.Very little true HD programing on the HD channels..it seems to be mostly SD.At least I know what to expect on the 4x3 channels. So,it's not just the viewers who haven't a clue.

It's snowing here right now, so I thought it'd be a good idea to go through and check signal strengths. Even on my weakest channel, the video plays without hiccups. Here's a screenshot:
http://i119.photobucket.com/albums/o121/mrx3750/signal.jpg

Just as a note, I don't like Springer. I just watched him long enough to see if the video would pixelate or drop out. It didn't, though apparently there were a few correctable errors in the video stream.

On another note: My antenna is still only about 6 feet off the ground, and is currently not pointing in the best direction, as I have been trying to pick up other digital stations. I therefore conclude that at least for local channels, OTA reception should not be too much of an issue regardless of weather. Rain and snow don't seem to have a great affect on the local channels.

One small update to add:

I have been further testing the cutoff point for signal strength. One of the major issues with HDTV being how well will people be able to receive OTA reception, I've been testing to see just how weak a signal can be before it cuts off.

I initally said a signal strength of 50% was as low as you could go before the video began to cut out, then I revised it to 70%. Based on more extensive tests, I am re revising the cutoff point to about 65% strength.

My updated signal strength meter (as seen in the screenshot in my above post) is more accurate then the one I was using when I started my tests. It has a range from 0 to 30 (Dunno why it's not 0 to 100, but whatever...) I have had smooth video with a signal as low as 18.7, BUT since signal strength fluctuates, a strength of 20, IE: ~65% seems to be as low as my tuner can accept without dropping the video at some point.

For my tuner anyway: if the signal strength is above 65% during a rainstorm or snowstorm, I can be very confident that I won't lose the signal.

If I get ahold of a better antenna and start bringing in distant stations, I'll examine how reliable they are and post my findings.

Reception of HDTV is driven by a combination of factors. Signal to noise, ghosting and interference are major ones. A windy day can make for rapidly changing ghost conditions, and the ghost cancelling system in the receiver might not be able to keep up. The transmitter tower bouncing around in the wind, trees swaying and so on. Movement can be a substantial fraction of the carrier wavelength up in the UHF TV band.

A windy day can make for rapidly changing ghost conditions, and the ghost cancelling system in the receiver might not be able to keep up.

I just confirmed that today...

Yes, I finally found something that affects the digital signal: Winds of 25MPH or more...

I had to point my antenna directly at the transmitter of the channel I was watching to eliminate the dropping out.

I hope this problem is solved when the stations go all digiotal and hopefully increase their output power...

I have seen the same issue in high winds. However, I am not sure the power increase will fix this. What is happening is that the digital locking circuit(probably some sort of PLL) is losing lock temporarily(and dropping data) due to the incoming wave varying. The variance is due to the distance from the transmitter to the receiver changing as the transmission tower moves in the wind. This is a basic problem with all broadcast digital transmissions.

At least for older analog TVs this is not an major issue, as their is no PLL in the tuner. However, there are effects in the analog picture such as varying levels of snow, ghosting, etc. in windy condtions also. In some cases, the analog TV is still viewable (with snow, etc). while the digital has frozen.

There are error correction circuits available for digital systems that can fix some of this. Of course, the transmitted signal must have enough error correction built in(this takes extra digital bandwidth) and the receiver must have the ability to use this error correction.

I have seen the same issue in high winds. However, I am not sure the power increase will fix this. What is happening is that the digital locking circuit(probably some sort of PLL) is losing lock temporarily(and dropping data) due to the incoming wave varying. The variance is due to the distance from the transmitter to the receiver changing as the transmission tower moves in the wind. This is a basic problem with all broadcast digital transmissions.



A very directional antenna aimed at the transmitter tower solves this. The directivity allows your receiver to ignore the ghosts, as the antenna doesn't let those ghosts get into the receiver. The ghosts that add and subtract signal strength and varyingly messing up the digital symbol "eye pattern". An "eye pattern" is a diagram (or scope trace) that shows the ability for a receiver to tell 1's from 0's in the received signal. Ghosts also cause earlier bits to mess up the bits now being received from the direct signal from the trannsmission tower. As the ghost signal path is longer, and the speed of light is not infinite, but is about a foot per nanosecond.

If there are no ghosts, the transmitter tower moving back and forth in the wind won't hurt reception. It doesn't impose enough doppler shift to be anything close to become a problem for the receiver.

ATSC television still has problems occasionally, even on cable systems. Time Warner Cable, the cable operator in my area, is supposedly completely digital now, but some of its channels act up from time to time. Case in point: I was watching a program on our area's ION-TV affiliate the other day, but couldn't follow the show worth a plugged nickel because the picture kept dropping out (leaving a blue screen), freezing and pixelating. (I have a recent-vintage 19" analog CRT TV with a digital cable set-top box ahead of it.) I think this may have been due to technical problems at the cable headend, the TV station itself, or even weather conditions at the time (I think it was raining or snowing when this showed up); difficult to tell now. I had a similar problem not long after Time Warner converted its systems (including the one serving my area) to digital; I was watching NBC Nightly News one evening and noticed the picture was freezing and pixelating like mad. I can only hope that once digital TV has completely taken over from analog, next year, that these problems don't happen more than once in a great, great while; it's no fun having your favorite show interrupted by aberrations such as pixelization or freezing in place for minutes at a time, not to mention dropping out entirely. Did analog TV ever have problems similar to this in the late 1940s-1950s, when the idea of transmitting pictures over the air was new? :scratch2:

As I have worked on integrated circuits used in digital telecommunications, I am very aware of what an eye pattern is. However, I am not yet convinced that ghosts (multipath signals) are the only issue.

It is probable that a directional antenna would help this. However, since I do not need a directional antenna for decent analog reception-I contend that this is one area where digital is not as good as analog. As I am only 30 miles from the transmitter in an area that is not terribly windy, and still have some trouble on windy days, I suspect people far away from the transmtter in windy areas(west Texas/Oklahoma for example) could have real trouble if they are depending on broadcast TV in 2009.

I picked up a Magnavox TB100MW9 at Wal-Mart last night for $50. I've got a small RatShack TV-FM combo up on a 25 foot mast, with a rotator and inline amplifier. I connected the converter with RCA patchcords to my Sanyo VCR, using the VCR as an RF modulator. This will enable me to videotape DTV programming.

For NTSC programming, I was able to pick up a maximum of 13 channels, with only six or seven of them able to be classed as "average" or better. Most of the others were always ghosting, or snowy to some degree. Some were downright awful.

With the converter, I can pick up 16 DTV channels (including subchannels) with no effort at all, and all look great. I don't even have to spin the antenna around to get the local channels! There was one CW channel I really wanted to get that's about 40 miles away because of religious programs on Sunday, but their DTV channel is a no-show. :( Their analog signal was rarely better than :yuck: in the past, and I'm positive it's because of signal loss due to the hilly terrain between the transmitter and my antenna.

So overall, I'm content. Not thrilled, but content.

Tom

Just finished watching a two hour long documentary on PBS about the steaming pile of failure known as the Iraq war. The video didn't drop out once.

My homemade antenna is VERY directional. In fact one of my issues is that the wind will rotate it a bit, and the signal strength will drop by 40%. However, when it's aimed right, reception is beautiful.

As for the problems on cable systems. That's happened with analog as well in the past. I remember as a kid having some cable channels that were either fuzzy, had ghosting, or interference, or spots on the screen, etc. Even had channels just drop to static. I expect there to be bugs in the digital system as well.

As far as drop outs, I only see these when it is fairly windy. Otherwise reception of DTV around here is fine. (The sets that I have been viewing DTV on are all 20+years old, so I cannot call it HDTV).

I do like the fact that there is no snow on DTV but hate it when drop outs occur. Unlike analog, even the sound can stop and the program you were watching cannot be followed again until the dropout is over.

the picture kept dropping out (leaving a blue screen), freezing and pixelating. (I have a recent-vintage 19" analog CRT TV with a digital cable set-top box ahead of it.) I think this may have been due to technical problems at the cable headend, the TV station itself, or even weather conditions at the time (I think it was raining or snowing when this showed up); difficult to tell now.
Check to be sure all the cable connections and splitters or any other devices you have within your home are tight and in good condition. If they are, call the cable company and tell them to fix their lousy system! You are paying them for a constant, high-quality signal under all conditions; weather is no excuse at all for signals carried over wires, any more than it would be for your wired telephone. (Digital cable is actually not ATSC in almost every case, but rather "QAM".)

73

Check to be sure all the cable connections and splitters or any other devices you have within your home are tight and in good condition. If they are, call the cable company and tell them to fix their lousy system! You are paying them for a constant, high-quality signal under all conditions; weather is no excuse at all for signals carried over wires, any more than it would be for your wired telephone. (Digital cable is actually not ATSC in almost every case, but rather "QAM".)

73

That's good advice. Every new place I've lived had serious cable signal quality problems. The Time Warner man spent over 4 hours here a few days ago replacing just about everything between the house and the pole until the internet, and digital cable worked properly. Don't let them blame your house wiring, or equipment. They always try to do that so they don't have to repair their own system. If you have to, tell him to run a new (temporary) wire between your cable box (or modem) and the main splitter.

As I have worked on integrated circuits used in digital telecommunications, I am very aware of what an eye pattern is. However, I am not yet convinced that ghosts (multipath signals) are the only issue.



Turns out the ATSC transmission standard uses an 8 level eye pattern
http://www.broadcast.net/~sbe1/8vsb/eye-diagram-g.gif

More info at:
http://www.broadcast.net/~sbe1/8vsb/8vsb.htm

I just confirmed that today...

Yes, I finally found something that affects the digital signal: Winds of 25MPH or more...

I had to point my antenna directly at the transmitter of the channel I was watching to eliminate the dropping out.

I hope this problem is solved when the stations go all digiotal and hopefully increase their output power...

I noticed that too, we had winds over 25 MPH yesterday here in Pittsburgh. I'm watching the WVU game on my 1964 Sony B&W portable using a Zenith DTV box. Excellent picture.

Something else I've been noticing the past week or so.

As time goes by, I've been seeing more tiling and random colored blocks on signals from stations about 25-30 miles away. I've also noticed that it seems to be getting worse by the day...

...in lock step with the leaves budding on all the trees.

You used to be able to see other neighborhood houses through the branches. Now that the leaves are all coming in, you can't see them. The more the leaves grow in, the weaker the DTV signals are getting. Some days I'm lucky to get a 10 on a 0-to-100 scale on the weaker channels... if I don't get a black screen and a "No Signal" message. This is all with an amplified TV/FM antenna with a rotator and inline amplifier, no less.

Swell. That means no digital CBS until late autumn. I think there's going to be a local digital translator next year, however. I hope.

Tom

Something else I've been noticing the past week or so.

As time goes by, I've been seeing more tiling and random colored blocks on signals from stations about 25-30 miles away. I've also noticed that it seems to be getting worse by the day...

...in lock step with the leaves budding on all the trees.

You used to be able to see other neighborhood houses through the branches. Now that the leaves are all coming in, you can't see them. The more the leaves grow in, the weaker the DTV signals are getting. Some days I'm lucky to get a 10 on a 0-to-100 scale on the weaker channels... if I don't get a black screen and a "No Signal" message. This is all with an amplified TV/FM antenna with a rotator and inline amplifier, no less.

Swell. That means no digital CBS until late autumn. I think there's going to be a local digital translator next year, however. I hope.

Tom

True. I once read a story about a UHF station in West Virginia back in 1952, one guy got a perfect signal from them in the winter but when the leaves came out, they blocked the signal and he lost all signal. The UHF station only put out in 12000 watts so as UHF goes, it was pretty weak. So far, here in Pittsburgh, I haven't noticed too much but I'll keep my eye on it. I know I live in the flight path and it seems the planes are taking off my house more than usual. I saw a 767 so low, I thought he was going to take out my maple trees. However, I notice some pixelation when planes fly over but it is tolerable.

I know after the 2009 sign off of NTSC, most stations will return to their normal frequencies, KDKA-TV's digital signal is on UHF channel 25 but will be back on VHF channel 2 and so on. The only exception is our Channel 11, it will stay on channel 48 and CW will take the channel 11 slot from where they are at on 19.

Ok, another update:

Don't rely on OTA HDTV if you want to get a perfect recording...

Recorded a PBS documentary on the Samurai sword. Even though I had a signal strength of 100%, there were still two occasions where half second drop outs caused blockiness.

The video is by all means watchable, but those two errors keep it from being perfect.

I tape stuff daily for other family members from the local NBC and ABC outlets' DTV signals. I'd say that at least once every week or so, either one of them is off the air for extended periods. The analog signals keep going, though.

The local cable company AFAIK still picks up and redistributes the off-the-air analog signals, so subscribers don't see any DTV OTA dropouts. Won't cable subscribers be in for a surprise when analog broadcasts are done and the cable company delivers OTA feeds of DTV signals that crap out every now and again!

Was early analog broadcasting this unreliable (if anyone remembers)?

I'd like to comment on this even though the thread is old. Last year I went on the FCCs web site to check the licenses of my local stations. In the Scranton-Wilkes Barre area in Pennsylvania, there is ABC, CBS, NBC, PBS, FOX, and Ion affiliates. Right now, they all digitally transmit at 10 to 30 percent of their analog counterparts. All of them. As an example, my local ABC affiliate transmits at 1150 kW ERP in analog. Their temporary (starter license when they first started transmitting ATSC) digital license has them broadcasting at 68kW ERP. Their permanent "pre-transition" license has them broadcasting at 100kW ERP. At 100kW ERP, I have occasional reception issues when using a vintage dual dipole with parasitic array, mainly because it has to be pointed in the right direction. Bad weather makes it worse but I have not really tested it because I have no interest in the programming on broadcast TV.

Their "post-transition" license is for broadcasting at 180k ERP (Wow). I'm guessing antenna location and transmit power is what it is for reasons such as the terrain, etc, but it just seems low. A rooftop antenna is required, at least in my area, for trouble free reception even in crappy weather. In my area you see rooftop antennas on many houses. Almost all of them are not used anymore, but the small indoor antennas just never cut it for this area. You can use them, and get acceptable quality, but rooftop antennas provided a stable picture.

Jonathan