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Klaas Robers wrote:One of the major problems Baird had is that the recording / play-back process on 78 rpm records works only more or less well at a speed of about 80 rpm (so: 78 rpm) The material did not work good enough at higher speeds, e.g. 160 rpm. Then he came to a system with about 5 frames per second. This might have been because also Baird had problems with the higher frequencies on a mechanical record. You are not the only one.
But if you run a Nipkow disc at that low speed your eyes just see a moving line, not a picture. Your eyes can follow the line and that is what they DO. Nowadays with some digital memory we can store the lines and show them as a still picture. And that is what Don McLean did. But even the long persistence CRTs that we used for displaying SSTV were not existing in 1930.! Baird had a hard time.
Viewmaster wrote:Harry, I think that this technique has already been mentioned here, but.....
…….I am building 2 seismographs with very low freq o/p's. ( can be more than 1 sec)
Hi there Albert no if so that slipped my mind ! i do wonder what you get up to i was reading the the musical Tesla device you were working on a while backSo in order to handle this I am modulating a 5kHz sine wave with the low freq.
Then feeding this into such as Audacity where the 5kHZ will not be seen,
but just the low freq 'waves' riding on top of the 5kHz as it were.
I wish I had tried this on my Edikow machine, way back, as 5kHZ sine wave was easily
recordable
Viewmaster wrote:I cheated on the recorded sync pulse problem as you know, Harry, and completely sidestepped it.
Became quite adroit in side stepping.
Just to recap....I ensured that there was an EXACT number of frames per rev. (2)
Then using using the adjustable radial angle of a mechanical pulse generator I was able to put an artificial
sync pulse just where I liked within a frame on playback.
So a recorded sync pulse was not required.
You can do the same if your recorded sync pulses don't work for you.
Take up side stepping, Harry.
Viewmaster wrote:Harry, if I were you, I would concentrate on getting reliable sync.
Without sync you're sunk !
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