5 ms·

So when he says "channel 3", what is meant by this? Is it a particular frequency? (I'm not an American)

ThePowerOfFuet 6y ago
Yes, the analog channels each had specific fixed frequencies.
iso1631 6y ago
I would guess it's VHF channel 3, which is from 60-66MHz, with the NTSC video carrier (Luma) on 61.25MHz, audio on 65.75MHz, and the Chroma carrier some nasty number about 3.58MHz above the Luma carrier. In my country, VHF TV transmissions started going out in the 60s when colour came in, and were fully turned off in the 80s. Modern DTV runs over UHF channels (replacing the previous analog transmissions between 2009 and 2012)
- alexisread 6y ago
  I don't know much about transmission, but would a modified version of this work for PAL TVs? I guess you'd modify the frequency but what to?
  - iso1631 6y ago
    PAL generally runs on an 8MHz channel, and encodes colour in an entirely different way (each alternate line is reversed, meaning that small errors cancel out - where in NTSC you had a "Tint" control to adjust to any errors).
    - ddingus 6y ago
      PAL also requires considerably more accurate and consistent color information. NTSC displays will usually take almost anything close and display it. See the Apple 2 video circuit for a great example of that.
      - iso1631 6y ago
        Hence "Never Twice the Same Colour"
        ddingus 6y ago
        With high persistence phosphors, PAL is nice. The higher frequency color makes a notable difference. 50hz was often just a bit slow for me. PAL 60 is where it was truly at, IMHO. Both formats have nice abuse potential, and exploiting it on early computers, and later on, microcontrollers, is a lot of fun.
- ficklepickle 6y ago
  Channel 3 (or 4) was also commonly the channel used by various peripherals like VCRs and composite adapters. I have fond memories of tuning the TV to channel 3 to play Nintendo as a kid. This would make for an interesting retro gaming experience. I wonder if it is easily adapted to use coax cable instead of an antenna.
  - bonzini 6y ago
    Europe used UHF channel 36 instead! Memories :)

Yes, the analog channels each had specific fixed frequencies.

I would guess it's VHF channel 3, which is from 60-66MHz, with the NTSC video carrier (Luma) on 61.25MHz, audio on 65.75MHz, and the Chroma carrier some nasty number about 3.58MHz above the Luma carrier. In my country, VHF TV transmissions started going out in the 60s when colour came in, and were fully turned off in the 80s. Modern DTV runs over UHF channels (replacing the previous analog transmissions between 2009 and 2012)

alexisread 6y ago
I don't know much about transmission, but would a modified version of this work for PAL TVs? I guess you'd modify the frequency but what to?
- iso1631 6y ago
  PAL generally runs on an 8MHz channel, and encodes colour in an entirely different way (each alternate line is reversed, meaning that small errors cancel out - where in NTSC you had a "Tint" control to adjust to any errors).
  - ddingus 6y ago
    PAL also requires considerably more accurate and consistent color information. NTSC displays will usually take almost anything close and display it. See the Apple 2 video circuit for a great example of that.
    - iso1631 6y ago
      Hence "Never Twice the Same Colour"
      - ddingus 6y ago
        With high persistence phosphors, PAL is nice. The higher frequency color makes a notable difference. 50hz was often just a bit slow for me. PAL 60 is where it was truly at, IMHO. Both formats have nice abuse potential, and exploiting it on early computers, and later on, microcontrollers, is a lot of fun.
ficklepickle 6y ago
Channel 3 (or 4) was also commonly the channel used by various peripherals like VCRs and composite adapters. I have fond memories of tuning the TV to channel 3 to play Nintendo as a kid. This would make for an interesting retro gaming experience. I wonder if it is easily adapted to use coax cable instead of an antenna.
- bonzini 6y ago
  Europe used UHF channel 36 instead! Memories :)