12

End Of An Era: NTSC Finally Goes Dark In America

 2 years ago
source link: https://hackaday.com/2021/07/14/end-of-an-era-ntsc-finally-goes-dark-in-america/
Go to the source link to view the article. You can view the picture content, updated content and better typesetting reading experience. If the link is broken, please click the button below to view the snapshot at that time.

End Of An Era: NTSC Finally Goes Dark In America

A significant event in the history of technology happened yesterday, and it passed so quietly that we almost missed it. The last few remaining NTSC transmitters in the USA finally came off air, marking the end of over seven decades of continuous 525-line American analogue TV broadcasts. We’ve previously reported on the output of these channels, largely the so-called “FrankenFM” stations left over after the 2009 digital switchover whose sound carrier lay at the bottom of the FM dial as radio stations, and noted their impending demise. We’ve even reported on some of the intricacies of the NTSC system, but we’ve never taken a look at what will replace these last few FrankenFM stations.

If you are an American you may have heard of ATSC 3.0, perhaps by its marketing name of NextGen TV. Just like the DVB-T2 standard found in other parts of the world, it’s an upgrade to digital TV standards to allow for more recent video compression technologies and higher definition broadcasts. It has an interesting backwards compatibility feature absent in previous ATSC versions; there is the option of narrowing the digital bandwidth from 6 MHz to 5.5 MHz, and transmitting an analogue FM subcarrier where the old NTSC sound carrier on the same channel would have sat. Thus the FrankenFM stations have the option of upgrading to ATSC 3.0 and transmitting a digital channel package alongside their existing FM radio station. It’s reported that this switchover is happening, with one example given in the Twitter thread linked above.

The inexorable march of technology has thus given better quality TV alongside the retention of the FrankenFMs. We have to admit to being sorry to see the passing of analogue TV, it was an intricate and fascinating system that provided a testbed for plenty of experimentation back in the day. Perhaps as we see it slip over the horizon it’s worth pondering whether its digital replacement will also become an anachronism in an age of on-demand streaming TV, after all it shouldn’t have escaped most people’s attention that in 2021 the good TV content no longer comes to your screen via an antenna socket. Meanwhile we’ll keep our CRTs running, just in case we ever want to relive a 1980s night in with a VHS tape of Back To The Future.

Header image: Mysid, Public domain.

Posted in HistoryTagged frankenfm, ntsc, television

Post navigation

29 thoughts on “End Of An Era: NTSC Finally Goes Dark In America”

  1. John Fenderson says:

    “The inexorable march of technology has thus given better quality TV”

    Not in my area. Every broadcast TV station around here has MUCH worse quality than they had with analog TV.

    1. Mike Szczys says:

      I have experienced this issue. It seems you could kind of put up with fuzzy analog TV signals. But digital just breaks up completely when you reach a noise threshold. You get a patchy checkerboard on the video and the auto starts to sound auto-tuned.

      That said, I get way more over-the-air channels after the digital switchover because the transmitters now have multiple sub-channels. That’s been pretty awesome.

      1. a_do_z says:

        I get no over-the-air channels after the digital switchover. I live in an rf shadow at the foot of a mountain which sits directly between me and the mountain where the DTV transmitters sit. Line-of-sight can’t see me. A channel scan finds zero digital channels using any antenna I had available.

        The FCC map pretty much confirmed my findings, pretty much saying, “You Lose”. The builders/previous owners of the home (early 1980’s) put an antenna in the attic. Given the effort it must have taken to get it there, and conversations with neighbors, analog TV worked sufficiently.

  2. Oscar Goldman says:

    “there is the option of narrowing the digital bandwidth from 6 MHz to 5.5 MHz, and transmitting an analogue FM subcarrier where the old NTSC sound carrier on the same channel would have sat”

    For what purpose? What can tune an analog FM frequency that’s outside of the 88-108 MHz band of normal radio? And what information would it carry?

    Regardless, this sounds like another dumb option that lets broadcasters reduce picture quality. It’s bad enough that our “advanced” TV standard allowed the hideous hacks that have plagued us for generations (interlacing and fractional frame rates) to persist.

    1. Nick says:

      TV channel 6 is 82-88 MHz. Many FM radios can tune just below 88 MHz down to 87.75 MHz where the audio subcarrier would be. That’s what this refers to. TV channel 6 is the only channel where this little trick works.

    2. Col_Panek says:

      Maybe it’s for the legions of people who use their TV as a radio. My dad among them.

    3. rnjacobs says:

      87.9 is part of the valid FM radio range in the US.
      87.75 is where TV channel 6 had its FM carrier.
      Every analog FM radio tuner could receive it. Most digital FM radio tuners could too.

  3. X says:

    ‘good TV content no longer comes to your screen via an antenna socket’

    Umm… Better TV content comes from an antenna. It’s not compressed like cable TV, there is no delay. Watch both side by side and the difference is apparent. For sports it makes all the difference, esp. for hockey, with live TV from an antenna you can actually see the puck as opposed to cable where it’s just a blur.

    1. Mike Szczys says:

      That’s a good point. My antenna connects via the F-socket on the back of the TV. This is the same one used by CATV.

    2. Jenny List says:

      I think you missed the point. Hit series’ these days? Very few of them debut on OTA TV.

      1. moo says:

        ah, yes the reader is at fault for failing to get the point, when you begin the paragraph referencing an improvement in the visual quality of TV, and then switch to making subjective judgement about the contents of the programming rather than the appearance.

        1. Wilko says:

          I understood the author perfectly. Yes, the reader is at fault.

    3. Ostracus says:

      Reminds me of C-band. So crisp the grass could cut you. Vivid blue sky’s meant something.

  4. Michael Black says:

    But NTSC was a retrofit. Analog tv goes back to at least 1939, 82 years ago, it was on display at the 1939 New York World’s Fair. It was broadcast, though very few had tv sets to receive it. But it built up, only to stall because of WWII.

    TV goes back further, but other schemes, and I’m not sure of exactly when the system in 1939 first started being used.

    So analog tv was around for a long time, color added, stereo added, extra information added. But all retrofits, having to work around the original standard. It lasted so long because nobody wanted to tamper with it.

    So DTV was a bold break, but after 70 years, a good time to reset.

    1. big F says:

      Cant think of many formats or systems that are still around that have been built on rather than scrapped in the technology arena. Maybe the XT IBM configuration thats just been added to over the last 30 odd years, is a good example.

  5. Bob A. says:

    NTSC, a.k.a. Never Twice the Same Color, we’re gonna miss you.

  6. not spam says:

    400 channels of time shifted Simpsons re-runs is good TV? No thanks, I will stick with my digital HD OTA over streaming, satellite and cable any day. Love Island? Doctor P[h]ill? Sorry but I don’t think the content on any TV is worth paying for these days. At least on OTA you get 16 hours of non-time shifted cr@p.

  7. Julian Silden Langlo says:

    If only it would take the gnarly 30000:1001 framerate with it.

    1. Bob A. says:

      That would be the wonky 29.97 FPS rate. It’s an artifact of cramming the chroma sideband into the existing 6 MHz bandwidth allocated per US broadcast TV channel when color was added in the early 1950’s. Prior to the introduction of color, the frame rate was set at a 30 FPS for US TV.

    2. Julian Skidmore says:

      This can be arranged, just move to Europe and enjoy a perfect 25 fps ;-) So much easier, so much better monochrome and colour resolution (625 lines and alternating colour phase) :-)

  8. Hirudinea says:

    NTSC will never die as long as I have an RF modulator, rabbit ears and a flagrant disregard for broadcast rules and regulations!

  9. Anonymouse says:

    Interesting. This was only a matter of time, but how long will Europeans last with their PALs?

  10. Nick says:

    The one real reason to continue supporting direct-broadcast radio or TV is for emergency broadcasting. The Internet doesn’t really support that. In essence, you could almost make the claim that if the internet’s up where you are, then it’s not really an emergency (if you define emergencies as those that result in activating the emergency broadcast system).

    In that context, the big loss in the switchover from NTSC to ATSC is support for mobile reception. You can’t watch ATSC in a moving vehicle essentially at all (continuously variable multipath and doppler will do it in). And, of course, as with any digital medium, there’s almost no margin between “perfect” and “no” reception.

    ATSC enabled the first repack because it reduced mutual interference concerns between harmonically related channels. The most recent repack had a lot more to do with the Internet killing broadcast TV (it was an outright goal – the proposition to the TV stations was, “how much can we pay you to give up your license?”).

    1. Nick says:

      I should amplify a little bit on the last point.

      The move to ATSC came along with reducing still further the UHF band down from channel 69 (it was channel 83 when I was a kid) down to 51.

      In other words, they didn’t do the digital transition for you. They did it so they could take 108 MHz of bandwidth away from the TV broadcasters.

      And last year they held a reverse auction to take away channels 38-51 (the top channel is now 36. Channel 37 was always and still is reserved as a radio astronomy window) – another 78 MHz.

      All of that bandwidth is now mostly cell phone bands (with some also being first responder / emergency services bands).

      1. Michael Black says:

        Out of WWII, TV got a big slice of spectrum, and then a bit later, more when UHF was added. It wasn’t because there were stations on every channel, but because technical limitations of the day required lots of spacing between stations.

        There was limited activity above about 50MHz before WWII. The advances during the war made higher frequencies more viable. But tv kind of froze things, grabbing the “good” frequencies before much use or demand for higher frequemcies. So as new uses for radio came along, they had to be squeezed out of existing allocations. CB was initially at 450MHz, Too high to be useful, and technology too expensive to be cheap.

        Technology kept improving, and a lot of things placed much higher because the space was there. And with time, they saw all those UHF TV channels unused, so they slowly got reallocated.

        Mobile phones have existed since the late forties. But the very arrangement meant few users could use it, and cost was high. Cellphones are a way more efficient method, and now just about everyone has them.

        DTV was a leap forward, I get better reception and more channels, and clearing out the old meant reallocating the spectrum.

  11. rclark says:

    End of an era.

    That said, I am not sure of the ‘point’ of TV anymore (we don’t have it). You can get your news and entertainment over the internet now at ‘your’ convenience… Skim the news at a glance. Read what you want to read… Saves time. Also look at what you want to see as far as movies and such on the entertainment side…. Not what the network wants you to see at ‘set’ times…. I don’t see the ‘value’ here is for TV.

    1. Nick says:

      Emergency broadcasting capabilities are still a really good idea.

    2. Rob says:

      It may come as a great surprise to some here, but not everyone is your age and of your particular persuasions. Fact is, there is still a large portion of the population, both in the US and around the world, who don’t have the luxury of a fat internet connection or a bank account to pay for the data service necessary to stream or download video content or the technological inclination or aptitude needed to do so. Multiple ages and socioeconomic demographics all continue to find value in over the air TV, and this is born out by the vast sums of money advertisers continue to happily pay to get their products in front of people’s eyes.

      The efficiencies of broadcast vs narrowcast are also undeniable, even as new hybrid models emerge to leverage the benefits of both. Fiberoptic backbones continue to be major points of failure in data networks, and yet most broadcast services are still there to provide news and entertainment to anyone who tunes in, and at no charge. It’s going to be a while yet before that model goes toes-up.

Leave a Reply Cancel reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.


report

Recommend

About Joyk


Aggregate valuable and interesting links.
Joyk means Joy of geeK