my birthday, c. 1972
I’ve kept this catalog bit in the pocket with the precision TV tuning tools.
I was too shy to ask for the vo meter option.
I still have most of the tools too.
hacking the 16mm optical track, notes
projector exciter circuit
there is a 26 frame offset between picture and sound
ie: 1.0833 seconds
- amplitude modulation: more light => more sound
- amplitude is the height of the wave, and
- frequency is the distance between wave crests
film moves at 24fps
there are 40 frames per foot, so film runs through the sound gate at 7.2inches/sec
to make middle C you would draw a waveform with 512 cycles per second. graphically that works out to:
512cps/7.2in = 71cycles per inch
- how hard is