6 ms·

Cathode Ray Television (1933)

60 points by takiwatanga 5y ago

agumonkey 5y ago
Mesmerizing. Clearly right to repair was honored at the time :)
- rob74 5y ago
  Well, if you built the contraption yourself, repairing it wasn't a problem...
martyvis 5y ago
The style of writing is amazing. You would think you are reading about a flower show or a fashion parade.
- bitwize 5y ago
  My brain read it in a sort of clipped "old-timey newsreel narrator" voice.
  - kingcharles 5y ago
    It's funny how that happens. I read it in this voice: https://www.youtube.com/watch?v=gou1cspUfdY https://www.youtube.com/watch?v=gou1cspUfdY
buescher 5y ago
"The views of Popular Wireless on the subject are too well known to require reiteration here, and our scepticism of the possibilities of the mechanical methods of transmission and reception have frequently been expressed." "When I was working at the Cavendish Laboratory at Cambridge I once get a bad attack of X-ray burn on the face, which was very irritating and painful for a few days - for all the world like extreme sunburn - but the tube I was using was not a cathode ray tube, it was very much ' harder' and enormously more powerful. After that, you may be sure that I took extra special care to avoid any possibility of a recurrence of the same experience, and, although I have worked with all kinds of cathode ray tubes, I have never found it necessary to take the slightest precautions against soft X-rays and I have never experienced the slightest harm." Ah, the good old days. Dude worked with Rutherford and Thomson, can we find anything on him?
- holoduke 5y ago
  Don't you think that x-rays have potential long term cancer effects? I worked with some medical devices in the past. Often after work I used the device in my own body or random equipment just for fun to see the inside. I didn't know anything about side effects..I am still alive 20 years later and i think it wasn't too bad. But still.
  - buescher 5y ago
    Another proponent of mechanical television!
  - CamperBob2 5y ago
    Well, sure, they're ionizing radiation. Of course there's an increased cancer risk, one that becomes more noticeable with increasing exposure. Normally we trade that off against their beneficial diagnostic properties, but this was an era when people didn't always think the tradeoffs through completely. X rays are the least of your worries with this project, though... this was back in the day when men were men, women knew their place (except for that uppity Marie Curie broad), and engineers wired headphone jacks directly to high-voltage B+ supplies. (See the schematic in this very article, in fact.) It's amazing our ancestors survived to pass on their genes. A lot of our would-be ancestors didn't.
- neilv 5y ago
  My top hobby project involving vintage electronics was spoiled when seeing, in eBay photos, vintage assurance labels about the level of X-rays emitted being safe. I don't know how much to trust that assurance from decades ago, and I don't know whether old and possibly damaged units are still within spec. in that regard.
  - ncmncm 5y ago
    Leaded glass does not lose its lead.
- chasil 5y ago
  The discussion on X-Rays was interesting, but I think their confidence was slightly misplaced. I know that I sat much closer than 6 feet as a youth. "It is, therefore, very doubtful whether any appreciable percentage of such rays would even get through the screen itself, let alone the glass wall of the cathode ray tube. In fact, very soft X-rays are absorbed by a few centimetres or even a few millimetres of air." https://en.wikipedia.org/wiki/Cathode-ray_tube#Health_concerns https://en.wikipedia.org/wiki/Cathode-ray_tube#Health_concer... "Concerns about x-rays emitted by CRTs began in 1967 when it was found that TV sets made by General Electric were emitting "X-radiation in excess of desirable levels". It was later found that TV sets from all manufacturers were also emitting radiation. This caused television industry representatives to be brought before a U.S. congressional committee, which later proposed a federal radiation regulation bill, which became the 1968 Radiation Control for Health and Safety Act. It was recommended to TV set owners to always be at a distance of at least 6 feet from the screen of the TV set, and to avoid "prolonged exposure" at the sides, rear or underneath a TV set. It was discovered that most of the radiation was directed downwards. Owners were also told to not modify their set's internals to avoid exposure to radiation. Headlines about "radioactive" TV sets continued until the end of the 1960s. There once was a proposal by two New York congressmen that would have forced TV set manufacturers to "go into homes to test all of the nation's 15 million color sets and to install radiation devices in them". The FDA eventually began regulating radiation emissions from all electronic products in the US."
Animats 5y ago
That's a very good receiver for 1933. Most television of that era was still rotating-disk systems. This receiver is intended to receive signals meant for Baird rotating-disk receivers. 12.5 FPS, 30 lines is the rate they give, although there was no firm standard at that point. For more info about early TV systems, see the Early Television Foundation.[1] [1] http://earlytelevision.org/ http://earlytelevision.org/
icehawk 5y ago
Its really interesting the action of scanning the tube seems to happen at 90° to what we normally consider the way an image is composed. The system has the lines go from top to bottom and then moves towards the left of the screen.
dschuetz 5y ago
CRT are the best displays to this day. Change my mind. I wish there still was more development on that. Yes they were noisy and heavy, but the picture quality! <3

60 points by takiwatanga 5y ago

agumonkey 5y ago

Mesmerizing. Clearly right to repair was honored at the time :)

rob74 5y ago
Well, if you built the contraption yourself, repairing it wasn't a problem...

martyvis 5y ago

The style of writing is amazing. You would think you are reading about a flower show or a fashion parade.

bitwize 5y ago
My brain read it in a sort of clipped "old-timey newsreel narrator" voice.
- kingcharles 5y ago
  It's funny how that happens. I read it in this voice: https://www.youtube.com/watch?v=gou1cspUfdY https://www.youtube.com/watch?v=gou1cspUfdY

buescher 5y ago

"The views of Popular Wireless on the subject are too well known to require reiteration here, and our scepticism of the possibilities of the mechanical methods of transmission and reception have frequently been expressed." "When I was working at the Cavendish Laboratory at Cambridge I once get a bad attack of X-ray burn on the face, which was very irritating and painful for a few days - for all the world like extreme sunburn - but the tube I was using was not a cathode ray tube, it was very much ' harder' and enormously more powerful. After that, you may be sure that I took extra special care to avoid any possibility of a recurrence of the same experience, and, although I have worked with all kinds of cathode ray tubes, I have never found it necessary to take the slightest precautions against soft X-rays and I have never experienced the slightest harm." Ah, the good old days. Dude worked with Rutherford and Thomson, can we find anything on him?

holoduke 5y ago
Don't you think that x-rays have potential long term cancer effects? I worked with some medical devices in the past. Often after work I used the device in my own body or random equipment just for fun to see the inside. I didn't know anything about side effects..I am still alive 20 years later and i think it wasn't too bad. But still.
- buescher 5y ago
  Another proponent of mechanical television!
- CamperBob2 5y ago
  Well, sure, they're ionizing radiation. Of course there's an increased cancer risk, one that becomes more noticeable with increasing exposure. Normally we trade that off against their beneficial diagnostic properties, but this was an era when people didn't always think the tradeoffs through completely. X rays are the least of your worries with this project, though... this was back in the day when men were men, women knew their place (except for that uppity Marie Curie broad), and engineers wired headphone jacks directly to high-voltage B+ supplies. (See the schematic in this very article, in fact.) It's amazing our ancestors survived to pass on their genes. A lot of our would-be ancestors didn't.
neilv 5y ago
My top hobby project involving vintage electronics was spoiled when seeing, in eBay photos, vintage assurance labels about the level of X-rays emitted being safe. I don't know how much to trust that assurance from decades ago, and I don't know whether old and possibly damaged units are still within spec. in that regard.
- ncmncm 5y ago
  Leaded glass does not lose its lead.
chasil 5y ago
The discussion on X-Rays was interesting, but I think their confidence was slightly misplaced. I know that I sat much closer than 6 feet as a youth. "It is, therefore, very doubtful whether any appreciable percentage of such rays would even get through the screen itself, let alone the glass wall of the cathode ray tube. In fact, very soft X-rays are absorbed by a few centimetres or even a few millimetres of air." https://en.wikipedia.org/wiki/Cathode-ray_tube#Health_concerns https://en.wikipedia.org/wiki/Cathode-ray_tube#Health_concer... "Concerns about x-rays emitted by CRTs began in 1967 when it was found that TV sets made by General Electric were emitting "X-radiation in excess of desirable levels". It was later found that TV sets from all manufacturers were also emitting radiation. This caused television industry representatives to be brought before a U.S. congressional committee, which later proposed a federal radiation regulation bill, which became the 1968 Radiation Control for Health and Safety Act. It was recommended to TV set owners to always be at a distance of at least 6 feet from the screen of the TV set, and to avoid "prolonged exposure" at the sides, rear or underneath a TV set. It was discovered that most of the radiation was directed downwards. Owners were also told to not modify their set's internals to avoid exposure to radiation. Headlines about "radioactive" TV sets continued until the end of the 1960s. There once was a proposal by two New York congressmen that would have forced TV set manufacturers to "go into homes to test all of the nation's 15 million color sets and to install radiation devices in them". The FDA eventually began regulating radiation emissions from all electronic products in the US."

Animats 5y ago

That's a very good receiver for 1933. Most television of that era was still rotating-disk systems. This receiver is intended to receive signals meant for Baird rotating-disk receivers. 12.5 FPS, 30 lines is the rate they give, although there was no firm standard at that point. For more info about early TV systems, see the Early Television Foundation.[1] [1] http://earlytelevision.org/ http://earlytelevision.org/

icehawk 5y ago

Its really interesting the action of scanning the tube seems to happen at 90° to what we normally consider the way an image is composed. The system has the lines go from top to bottom and then moves towards the left of the screen.

dschuetz 5y ago

CRT are the best displays to this day. Change my mind. I wish there still was more development on that. Yes they were noisy and heavy, but the picture quality! <3