Sanabria television sound and video same channel

[Harry Dalek]

Heres an experiment not tried out since 1928 ...these days we use a second channel for voice but looks like there was another way back then.

[DrZarkov]

I can't believe that this would work properly. As we all know, we can hear the NBTV signals very well. There will always be disturbances.

I read an a Dutch article from the late 1920s or early 1930s about the idea to put the sound signal somehow compressed into the moment, when the sync-impuls is transmitted, or just use one of the 30 lines for sound, similar to the light sound system used at the cinema. Now with digital technology this would be possible, but I doubt very much that this idea ever worked with analog television. If you would use for example line 30 for sound, you would have to record it and play it back in 1/30 of the recorded speed. With an analog 5 kHz AM radio channel it would mean to put the sound in only 167 Hz, which is impossible. If you use a higher bandwidth, you can use as good (or better) two channels for picture and sound.

[Harry Dalek]

I can't believe that this would work properly. As we all know, we can hear the NBTV signals very well. There will always be disturbances.

Hi Dr Z
Its interesting as i sounds like it worked but as they say at times it broke up the video also what i didn't tell you it was a colour system they were trying !
It was a trail of a 3 spiral colour system of 15 lines for each of the 3 colours .
Its in one of the 1928 magazines i just posted a link up a few days ago .

I read an a Dutch article from the late 1920s or early 1930s about the idea to put the sound signal somehow compressed into the moment, when the sync-impuls is transmitted, or just use one of the 30 lines for sound, similar to the light sound system used at the cinema. Now with digital technology this would be possible, but I doubt very much that this idea ever worked with analog television. If you would use for example line 30 for sound, you would have to record it and play it back in 1/30 of the recorded speed. With an analog 5 kHz AM radio channel it would mean to put the sound in only 167 Hz, which is impossible. If you use a higher bandwidth, you can use as good (or better) two channels for picture and sound.

I Don't think they had Stereo back then but yes thats a much better idea suppose why we use it day simple ...
Perhaps the voice used all the bandwidth up when they used it and this is what they saw when it broke up the image ? Not sure about the frame rate and or the 15 colour lines make in the bandwidth any case it was an experiment i never heard of ,the magazines you can download are amazing to me what they used back then just doing electronics in general
magnetic diodes ! oscillator tuning forks with electro magnets a hell of a lot of lost know how i love reading this stuff you think they knew bugger all back then but they just found another way of doing the same thing with what they had at hand.

[Lowtone]

Sounds like ADSL thing, low frequencies for telephone, high frequencies for internet, with a filter at the end of the line