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MY home constructed PhonoVision Mechanical video recorder
Hi i wanted to see if i could make a mechanical video recorder i was thinking at the start if i was lucky i might be able to do 8 sec SSTV which i did manage to do ...
I really wanted try Bairds mechanical recording idea but never thought i would get to this ...the Build is here from the start not even being able to even record a sound well .. https://www.taswegian.com/NBTV/forum...hp?f=12&t=2747 Well jumping to Bairds PhonoVision 30 lines 5 frames a second at 78 Rpm he was never able to view the discs well if at all at 5 frames a second you would need a long phosphor CRT screen.so he never did show the results to the public,and sort of gave up onit . I sort of know the problems he had working on this ..big problem was he had a lack of bandwidth for the recording head i would say with what he had he was luck to have had around 6 khz . Play back is very fussy so drift is a problem even for me now . My system was use a converted old record player make a new tone arm and geared record arm and try the recordings at around 78 rpm . The record head idea one was i got to record SSTV on a converted tiny stepper motor with embossing needle soldered on its arm i had a bandwidth up to 8 KHZ few dips bandwidth up to there but fine for 8 sec SSTV . When i got results with sstv i knew NBTV 32line 12.5 frames a sec might be possible so the next step was record and see with the old head and i did get poor results . Next i used an idea i had hook a 100 watt amplifier up to a normal untouched ceramic play back head and use it to embossing the tracks and video ..i knew it had a 20 khz bandwidth on play back record ? well its good enough much improved not 100 % but i can view and show my results . Youtube some results top row https://www.youtube.com/channel/UC9e..._E3FpVgyObW8LA |
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