The little mechanical SSTV the second generation

Forum for discussion of SSTV topics. Slow Scan television (SSTV) is a picture transmission method used mainly by amateur radio operators, to transmit and receive static pictures via radio in monochrome or colour.

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The little mechanical SSTV the second generation

Postby Harry Dalek » Sun Apr 02, 2017 9:30 pm

Have in mind to down size my original SSTV laser monitor at this stage i am not even thinking of casing it .
i was going 2 mirror system for a flat screen but i can't beat this instant start a new frame that the drum does a framing mirror i would have to wait and line it to start a new frame can't beat the unbeatable the drum screen is better for a mechanical system that way ! :roll:
Having thought about it now for a while i think i can fit it all on a circuit board motors drum and circuits
Hindsight makes making a second one much easier you know what will work and what won't ,i want to down size every thing and the hardest thing to down size is the framing movement lucky for me i had a few tiny dc geared motors even so picking the best slowest still to fast still have to use and extra gearing to drop this .
I am going DC motors for both the framing drum screen and line mirror i think i can sync it so not using stepper motors drops the circuits needed but make it all less accurate apart from the framing which is helped by the gearing and slow speed of it on that side of things /

At this stage i have tested the geared motor and its extra gears this working makes it all possible .
No pictures to show and tell yet .
Last edited by Harry Dalek on Wed Apr 05, 2017 7:47 pm, edited 1 time in total.
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Harry Dalek
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Re: The little mechanical SSTV the second generation

Postby Harry Dalek » Mon Apr 03, 2017 7:10 pm

Here is pretty much the mechanical framing screen drum part of it reusing these gears from an old printer since i am not good at making stuff i have to resort to repurpose this increases the size such depending what i have got handy.
Also here the size of the circuit board i am thinking the drum will be above the circuits such depending how much of the board i use and the position of the line mirror motor ...need to pick a uv laser i have handy and put these 3 things together .
The large gear the drum is on is only there because the drum fits on it and its back fits around the last gear saves me having to line up center the drum .
The Line mirror has been put on this little dc motor i will need to mount a opto switch so the edges of the 4 sided mirror brake the light to the sensor so i can then use that for feed back and the sstv sync via a bistable circuit and have some line syncing happening .
I am thinking once the framing screen drum speed is adjusted that can free run worked fine before so i can't see why not now .

youtu.be/uiylzYgA_G8
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The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Harry Dalek
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Re: The little mechanical SSTV the second generation

Postby Harry Dalek » Wed Apr 05, 2017 7:39 pm

Well have not had much time to construct last few days but today i got a can of the glow paint The White Knight one in the picture used in my past mechanical sstv project ...
i could not remember if that was the grainy paint i first used or the better fine grain which i wanted lucky the The White knight is the better one and only one left at my hardware store /
..also a while back i tried mixing some of the longer Persistence orange glow powder with white paint think it was hobby Acrylic that seemed to work changed the orange to green glow when charged with the UV laser have to track down remember what i have done with it and try it with other paint colours i was not expecting the colour of the glow to change .

I also looked into the laser i have 2 uv laser diodes lesser power and 2 higher power lasers with adjustable lens fine for this but i might be in the same boat as last time where the laser diode might or more than likely has a regulator board so no good to modulate it also has the similar problem in that it is enclosed in its aluminum heat sink tube so i will have to cut it open as i had to do in the first version but i will test it out hooking it up to the first mechanical SSTV just in case and save me so the work if i am wrong .
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The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Harry Dalek
"Fester! Don't do that to 'Thing'"
 
Posts: 4084
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Re: The little mechanical SSTV the second generation

Postby Harry Dalek » Thu Apr 06, 2017 7:50 pm

Changes today i found the smaller half size aerosol can lid sort of fits better to the aspect ratio ....thats as big as i would go on this one just also happens to fit over the large gear nicely .
Problems that now may come into play how true the square laser mirror rotates on the dc motor the 4 lines have to over lap the scan line width has to fit the drum and focus distance so i will work on all that before i mount the motor and laser in place playing around a little with that today ..i need to get the line mirror motor hooked up to really see how i can adjust the line width close to the drum width .
Notice the hot glue top of the line mirror glows very bright under uv light

youtu.be/DvLTot788O8
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The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
User avatar
Harry Dalek
"Fester! Don't do that to 'Thing'"
 
Posts: 4084
Joined: Fri Sep 26, 2008 4:58 pm
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Re: The little mechanical SSTV the second generation

Postby Harry Dalek » Fri Apr 07, 2017 8:10 pm

Testing the DC motor i was hoping to use for the line mirror ended up there was a slight vibration causing the laser lines not to run true over each other so i swapped to another scrapped from cd or dvd player this seems good enough ...all lines over lapping .
Last picture about the length of time 8 sec's for blank raster running the geared frame motor on 5 volts a volt of so more might get a square the aspect ratio for Slow scan .
The you tube video i was looking for line Persistence manually switching the laser on off...getting there .

youtu.be/vkY6Eg9Z2XE
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The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
User avatar
Harry Dalek
"Fester! Don't do that to 'Thing'"
 
Posts: 4084
Joined: Fri Sep 26, 2008 4:58 pm
Location: Australia

Re: The little mechanical SSTV the second generation

Postby Harry Dalek » Sun Apr 09, 2017 7:43 pm

Started work on the slow scan demodulator had all the parts in my junk box so far the 741 circuit bits ,not sure if i will use 555 sync separator might use the Klass circuit i used on the crt monitor .
Will test whats made and move on hopefully ,next i will add the PWM circuits for the laser .
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The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
User avatar
Harry Dalek
"Fester! Don't do that to 'Thing'"
 
Posts: 4084
Joined: Fri Sep 26, 2008 4:58 pm
Location: Australia


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