how much harder is DTV?

[darklordchris]

i don't know if this would be the correct form for thiis

so with the end of normal analog television broadcats in the usa today i started wondering about how much different and more complicated are the eqiupent used for digital tv broadcasts? i have been involved in some low power radio experiments in the past, so i have been some what introducted to some of the tech from analog tv broadcasting as a by product i suppose.
and also other then more space on the band, ....which is good, don't get me wrong..... whats so much better about dtv anyway?

 

[dknguyen]

I think the biggest advantage was lower bandwidth. Also, the quality is more consistent (not necessarily better- depends on the transmission quality). The image stays the same quality as the signal gets weaker, until it cuts out altogether. But bandwidth is the main thing since RF bandwidth is a very limited precious resource.

 

[darklordchris]

I think the biggest advantage was lower bandwidth. Also, the quality is more consistent (not necessarily better- depends on the transmission quality). The image stays the same quality as the signal gets weaker, until it cuts out altogether. But bandwidth is the main thing since RF bandwidth is a very limited precious resource.

yeah i think your right. however even on my friends cable i've been see more screw ups then i've ever seen with the old technology.....even with olt the over the air transmiting

 

[blueroomelectronics]

A good antenna and proximity to the tower makes a big difference.
Try **broken link removed** to see what sort on antenna you need for your location in North America.

 

[Torben]

I like some digital TV when it's good quality, but I have to say that I prefer the smoother degradation that analog gives with poor signal strength. I hate the blockiness and jerkiness that happens when a digital signal starts to break up, whereas some snow/static in the image when analog starts to degrade is a lot easier for me to take. Maybe I'm just used to it though since I grew up out in the boonies and we had to change channels by going out to the goat barn and rotating the antenna pole which was strapped to the end of the barn.

I especially hate when I'm watching sports and and something goes sideways with the digital transmission--suddenly I'm watching a blocky slideshow. Bleah.

What I really don't like are gigantic TVs which are so sharp that the compression artifacts are highly noticeable in the image.

On the other hand, a good strong and high-quality digital image is simply stunning.


Just my $0.02 CDN,

Torben

 

[crutschow]

Another advantage of digital is the ability to readily store the signal digitally on a hard drive without having to convert from analog to digital to store it and then back to analog to replay. It stays digital all the way and thus makes DVRs a lot simpler.

 

[Torben]

Another advantage of digital is the ability to readily store the signal digitally on a hard drive without having to convert from analog to digital to store it and then back to analog to replay. It stays digital all the way and thus makes DVRs a lot simpler.

Although the MPAA and Hollywood seem to think that the best thing about digital is that they can try to enforce the closing of the "analog hole" through encryption, forced quality degradation, and DRM. . .so if they have their way storing the digital copy will be tough. Not that this is going to make a dent in piracy like they hope it will.


Torben

 

[darklordchris]

Although the MPAA and Hollywood seem to think that the best thing about digital is that they can try to enforce the closing of the "analog hole" through encryption, forced quality degradation, and DRM. . .so if they have their way storing the digital copy will be tough. Not that this is going to make a dent in piracy like they hope it will.


Torben

yeah your right. also the goverment will be selling off large portions on the bands that once went to analog broadcasting to ceil phone companys.
so i got bored and read about pirate tv on wiki

Pirate television - Wikipedia, the free encyclopedia

now i'm starting to wonder if a desire to stamp out potential compation from alternative media was a potential concern for the industry as well

 

[dknguyen]

Wouldn't you agree that "Dark Lord Chris" doesn't have as much of a ominous or threatening ring to it as other names? I mean can you hear people saying "Run! The Dark Lord Chris coming!" just doesn't sound right. You'd have to work extra hard to inspire fear with a name like that. My theory is that you need a two syllable name- Vader, Sauron. THose seem to work. Three syllables is too much...think about Voldemort...that name just sounds stupid. Then again, Dark Lord Christoper doesn't sound so bad even though it has 3 syllables, but it doesn't sound as good the Dark Lord Christoph which only has two.

Like Dark Lord Torben sounds much better. Dark Lord Chris is about as fear-inspiring as Dark Lord Jiggly Puff.

 

[darklordchris]

Wouldn't you agree that "Dark Lord Chris" doesn't have as much of a ominous or threatening ring to it as other names? I mean can you hear people saying "Run! The Dark Lord Chris coming!" just doesn't sound right. You'd have to work extra hard to inspire fear with a name like that. My theory is that you need a two syllable name- Vader, Sauron. THose seem to work. Three syllables is too much...think about Voldemort...that name just sounds stupid. Then again, Dark Lord Christoper doesn't sound so bad even though it has 3 syllables, but it doesn't sound as good the Dark Lord Christoph which only has two.

Like Dark Lord Torben sounds much better. Dark Lord Chris is about as fear-inspiring as Dark Lord Jiggly Puff.

yeah i use't to use dark lord christoph actually, but its to hard to remember


anyway so back to the tech side of things. anybody know how much different the equipment to broadcast in digital is?

 

[blueroomelectronics]

Do you want to build your own ATSC (assuming you're in North America) TV station?

 

[crutschow]

The transmitter is not that different. It's the digital modulator that's completely different (don't even think about trying to build your own.)

 

[Krumlink]

A good antenna and proximity to the tower makes a big difference.
Try **broken link removed** to see what sort on antenna you need for your location in North America.

Thats a fun site to play with; i find making the antenna 500 ft above ground level gives you satisfactory results

 

[darklordchris]

The transmitter is not that different. It's the digital modulator that's completely different (don't even think about trying to build your own.)

naaaaaw i don't really have any intrest in television broadcasting, but like i said,
i'm kinda familiar with the tech from some of my radio studies so its an intersting topic i think

 

[darklordchris]

Thats a fun site to play with; i find making the antenna 500 ft above ground level gives you satisfactory results

theirs another question. whats up with the new antennas? whats so different about an antenna? they all look like some star trek ****, like an alien spaceship.

i have a dtv attachment for my computer , and it just uses a regular telivision antenna

 

[mneary]

The "new" antennas only have to cover 177 to 803 MHz, which makes them smaller and/or more efficient. Many customers on the fringes, as noted by Torben, will find their weak signals unacceptable and need more gain to stop the splotching.

 

[flat5]

177 to 803 MHz...that's still a lot of bandwidth.
How many stations can occupy that?

There are a lot of friendly names. Dark Lord Buffy Dark Lord Sam. I don't think syllables make the difference. Jimmy, Larry, Bernie. (Can't end with "e") It should sound foreign and starting with an uncommon first letter may help. Exitor, Yourlic, Zqurkenphk. Ok, I'll stop.

 

[crutschow]

177 to 803 MHz...that's still a lot of bandwidth.
How many stations can occupy that?

Channels 7 through 69 with each channel requiring 6MHz BW (there are other service allocations in the remaining bandwidth).

 

[flat5]

Thank you. 6mhz for video and audio. The analog system required...?
An NTSC television channel as transmitted occupies a total bandwidth of 6 MHz.
Here is more than you want to know.
NTSC - Wikipedia, the free encyclopedia

Pal requires 6,7, or 8mhz
Broadcast Specifications for PAL

So I don't see how bandwidth is improved by the new system.

Reading more about digital Tv I am not able to confirm the 6mhz bandwidth.
Digital television - Wikipedia, the free encyclopedia.
Mainly because it's over my head

 

[mneary]

I just learned that the final band plan only uses channels 7 through 52 (699 Mhz) in places like Los Angeles.

In many places digital is supposed to only use UHF; physical channels 14 (473 MHz) to 52 (699 MHz). That could be a pretty small antenna, even with pretty fair gain.

Interesting - here in coastal LA county, KTTV("11") and KCOP("13") have vanished completely since moving their digital programming from temporary physical channels 65 and 66 respectively back to their original physical channels. Their FCC filing says they wouldn't lose any coverage?

[edit]About bandwidth: ATSC is the digital system adopted in the US, it uses a modulation system known as 8VSB, described in detail on Wikipedia. The same 6 MHz channel is allocated, and the net data rate is 19.39 Mbits/sec. This is a digital stream containing video information. I see some channels providing one high-definition program, and others providing up to eight different low-resolution video programs.

The selectivity of modern receiving equipment makes it possible to place stations on adjacent physical channels (such a 65 and 66 that I mentioned above).[\edit]