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#1
03-17-2020, 03:53 AM
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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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#2
03-17-2020, 04:12 AM
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Here is my PhonoVision video recorder player and spike M NBTV result on play back .
I record the sync pulse but play back speed of the platter is more of a problem i am still working on . I will post up some other things i find on the device but best to view the build in the last post link ...Any Questions just ask .
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#3
03-17-2020, 04:30 AM
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Some images of the Beast , the Gearing for the mechanical record arm was made from old scrapped laser printer and a little gear box i had .
Has to be very slow for the tracking ..all very much trial and error one step at a time .
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#4
03-17-2020, 11:26 AM
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Cool build.
Did you have to modify the cart or styli on that chuo denshi cartridge? What tracking weight is the record arm configured for? Did you wire the cart for lateral mono recording? I may try duplicating that set up for audio recording.
__________________
Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4
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#5
03-17-2020, 11:15 PM
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Quote:
For record this surprised me it worked as is ,you need a 100 watt amplifier for it unless you have a magnetic cartridge and the output of your lap top is enough ! The weight for the record arm is experimental not enough it will emboss a track but tone arm stylus will not track you pretty much just increase the weight a washer or tiny magnet ..i was lucky on the second build here the stainless steel arm was ,i never bothered to weigh it it was all trial and error feel for what worked what didn't . Lateral recording at the moment both L R are wired to get for mono but plans are for a stereo track video on one side and audio on the other . Good luck if you try it small steps get you there in time .
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