NBTV Camera Question

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Postby Harry Dalek » Fri Jun 01, 2012 12:49 am

Today i have built the video sync mixer from news letter 15,3 seems to be mixing the 2 from my first power up tests but need to do a video test .
Heres a short video of the camera running you might like to adjust the brightness up a little on your player .
I will see how the mixing gos tomorrow got my fingers crossed :wink:
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Picture 32117.mpg
the fly spot running as you see very low light levels
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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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Postby Harry Dalek » Sun Jun 03, 2012 1:40 am

The tests yesterday night i was getting about half screen images on the pc via Garys Bigscreen software ..Speaking with gary showing him the results of the video test it looks like i am giving my sync video mixer to wide a pulse .

So am going to stick a monostable with pulse width control between the reflective sensor encoder circuit and the video mixer to fix this problem.

All gos well the camera will be pretty much camera to pc viewable full screen not adjusted by software ......record and live + playback .

One last thing i have been working on today is Motor control ...a clock which i would like it to be a crystal controlled oscillator 400hz feeding the 4066 pll as per normal motor control but for a camera this time..

The problem of viewing live and recording to pc i need a stable motor locked to the correct speed other wise there will be drifting not so much a problem for mechanical to mechanical but to pc a big problem..Gary has pointed out the clock could also be 400hz signal from another pc or perhaps on the lower standard side just a 555 but i would rather crystal control...i am at the moment making the circuit and i will be able to switch between clocks to test out of interest.
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Postby Harry Dalek » Tue Jun 05, 2012 11:33 pm

Still on the boring stuff sorry, finished the crystal clock for the 4066 pll motor control circuit seems to work fine so well worth copying if i can make it you have hope !

I plan to try a live to PC view tomorrow just using the encoder circuit with the video mixing i will post the results ,heres one of the waves of the about half a screen due to my sync pulses being to wide you may find it of interest in its evolution .
No 3 is IXTV letters moving up down the screen and at end might notice my fingers moving very low def but its in sync only half there ; (....SO FAR ! ; )

I want to do a live view mainly to see if i can adjust the thing bit hard when doing it in bursts record view so thats why i am keen to really get the thing viewable on a pc.

BTW i would use Garys big screen software to view it seems to work best on that ..
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syncmixer3.wav
IXTV test card and my fingers right at the end
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Picture 075.jpg
My clock motor control board
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Postby Harry Dalek » Wed Jun 13, 2012 4:09 pm

Have not posted for a while again , gary and i have been working out each little problem as its been rearing its head...
I now can mix the video and sync correctly,the video here i have not adjusted the sync pulse to the right width so this will play fine on garys Big screen nbtv but be a bit wavy on doms .
In the interest again in its evolution i bring you my hand and fingers in NBTV.
Now i just have to run the motor via crystal control and use a nipkow with a touch smaller hole which i have but have to paste another encoder disk on
Also the lens is reversing the image .
Does any one know if an NBTV camera has ever been made to NBTV standards ? from what i have read its either a closed system monitor camera on same disk or shaft ....or the speed control is manual so they would be close but not 100% NBTV ,i would like mine to be that and it might just do it ,i have a secret weapon Gary !

:wink:
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syncsweepvideomehand.wav
my hand fingers in sync test
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Postby aussie_bloke » Thu Jun 14, 2012 12:30 pm

Just opened up the file in "NBTV The Big Picture" and can see your fingers waving up and down, excellent progress you've made so far, keep up the great work! :D
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Postby Harry Dalek » Thu Jun 14, 2012 7:14 pm

aussie_bloke wrote:Just opened up the file in "NBTV The Big Picture" and can see your fingers waving up and down, excellent progress you've made so far, keep up the great work! :D



Heres my set up troy ...as i do my late night tests ...

Yes even oprah winfrey likes nbtv :wink:

I am playing around with the lens at the moment to get the flying spot ...spot tinier to get a sharper focus....

Close and big is ok but not so go the other way around...i did some tests with the monkey toy you see in the picture i can just make it out with the tests but i can see it needs better focusing ...doing some more tests tonight.
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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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Postby gary » Thu Jun 14, 2012 7:55 pm

Harry, if you have access to an old microwave oven you could rip out the turntable mechanism to make a rotating platform for the monkey - it's amazing the difference that bit of motion makes. It uses main power however, so be careful if you do. (Others, don't try this if you are not experienced/comfortable with working with mains electricity).
Perfecting an NBTV system is like trying to slam a revolving door...
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Postby Harry Dalek » Thu Jun 14, 2012 9:37 pm

gary wrote:Harry, if you have access to an old microwave oven you could rip out the turntable mechanism to make a rotating platform for the monkey - it's amazing the difference that bit of motion makes. It uses main power however, so be careful if you do. (Others, don't try this if you are not experienced/comfortable with working with mains electricity).


Wow i never thought of that Gary !

I have pulled a few of these things to bits over the years but never that part darn worse part i just got rid of one 2 weeks ago .

i tried to do a bit of rotate by hand but focus is tight with a smaller raster dot should be better, i have worked out a way i tested this afternoon and i will try that tonight ...my internet is on the crawl again so i will only post if its worth it.

When i am happy with that i'll put the crystal motor control in .

I might have to go very low tech and get a record turn table out and try that by hand rotating till see an old micro wave oven on the side of the road !!! i have an old once hand cranked lp player some dreadful person in the 1950s guttered it and made it into a tacky electric conversion of the time ...bad enough but the person also drilled holes every where least the turn table is original .
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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Postby Lowtone » Thu Jun 14, 2012 11:05 pm

I like your handmade testcard :P
r a d i o P T T v i s i o n
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Postby Harry Dalek » Fri Jun 15, 2012 12:42 am

Lowtone wrote:I like your handmade testcard :P


You see that a while post wise back in one of the videos Gary helped to ad sync before i tried .

Heres the monkey test tonight i was opening its mouth thats the movement there ...still pretty basic trying to improve .
This one even plays on Doms not to bad and both of Garys big screens .

Have to point out the video is upside down...! the lens flips the image !!! i view with lap top up side down :shock:
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monkeyface.wav
Heres close up monkey face one side
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monkeyfacetrainme.wav
Heres` me up side down looking around the camera...view small and upside down : }
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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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Postby Harry Dalek » Sat Jun 16, 2012 1:36 am

Today i lined up the encoder disk and reversed the motor to get the image the right way around.

I was happiest today with another go at filming toy monkey looks a lot clearer in this .

One i was not expecting to work was my cat face test card so up loading this as well.

I view them on garys big screen half size getting there ..
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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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Postby gary » Sat Jun 16, 2012 1:05 pm

Harry, for some reason your change to the encoder didn't seem to work.

Here are time base corrected versions of above in AVI - wave files available if requested (not posted this time simply because they are larger than the AVIs)

Harry, your cheeky monkey came out quite well! (abject apologies if it was, in fact, a self portrait :shock: ;-))
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Postby Harry Dalek » Sat Jun 16, 2012 2:17 pm

gary wrote:Harry, for some reason your change to the encoder didn't seem to work.

Here are time base corrected versions of above in AVI - wave files available if requested (not posted this time simply because they are larger than the AVIs)

Harry, your cheeky monkey came out quite well! (abject apologies if it was, in fact, a self portrait :shock: ;-))



Hi Gary

OH still problems i will take a picture of it and post ! But the missing pulse part is between the first and last line must of stuffed it up again...mmm

Some thing is up again gary looking at the sweep tests on the pulse width i sent you on both i got no rolling bar and the the top of the picture is not Jagged and is fine some thing has changed since then...can only think its the pulse width adjustments off again .
The rolling bar i am going to have to track down ,i know i forgot to switch off the lap top power supply which is very noisy .

Apart from that i could tell the monkey was a lot better for for what i have been getting but i know this thing still needs a bit of work to keep me busy :wink:

No that fines gary good putting those on here as its a good learning thing for every one and me ! I will have a look at them now .

Oh and thankgoodness it is still the monkey not me .....i think :wink:
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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Postby gary » Sat Jun 16, 2012 3:10 pm

harry dalek wrote:OH still problems i will take a picture of it and post ! But the missing pulse part is between the first and last line must of stuffed it up again...mmm


Well if that is the case I find it hard to explain it unless there is some sort of delay in the electronics - damn long delay though.

harry dalek wrote:Some thing is up again gary looking at the sweep tests on the pulse width i sent you on both i got no rolling bar


Do you mean the vertical bar that rolls horizontally or the rolling of the sync bar (picture)? I haven't seen any of your tests yet that doesn't have the vertical bar that scrolls across.

and the the top of the picture is not Jagged and is fine some thing has changed since then...can only think its the pulse width adjustments off again .


Well the bottom of the sync bar will be flat only because that's the trigger for the start of the line - but the top of the sync bar will be jagged NOT because of the sync width (which IS fine BTW) but because your disk speed is varying - if you look at your wave files WITHOUT sync processing you will see the sync bar being a great wavy thing - this is disk speed variation - something you haven't addressed yet.

There is SLIGHT jaggedness on both sides of my avi's because the time base correction has changed the length of the sync pulse to make all lines in the video signal the same length (i.e. correcting the line length variation due to speed variations). But I can only do this to a 1 pixel resolution without greater oversampling (perhaps I should do that actually).

The rolling bar i am going to have to track down ,i know i forgot to switch off the lap top power supply which is very noisy .


Yes I think it must be something external as it is at none of the internal frequencies - but it is much lower now than it used to be.

Apart from that i could tell the monkey was a lot better for for what i have been getting but i know this thing still needs a bit of work to keep me busy :wink:


Yes, that's the first time I have actually recognised it - so that's a big step forward.

And yes, NBTV work is good for us... keeps us off the street :-)

And anyway, I think you are now one of a surprisingly small number of NBTVA members who have created a recognisable TV picture mechanically - well done!
Perfecting an NBTV system is like trying to slam a revolving door...
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Postby Harry Dalek » Sat Jun 16, 2012 4:10 pm

Hi Gary

Well if that is the case I find it hard to explain it unless there is some sort of delay in the electronics - damn long delay though.


Looking at the pasted paper over that position the top line does have a little overlap i think due to the fact the encoder is smaller than the nipkow part so at that point the difference in sizes is made up in the overlap ...i think ! i can cut it smaller but the line pule will be wider ...all the white slots line up to the nipkow holes ...


Do you mean the vertical bar that rolls horizontally or the rolling of the sync bar (picture)? I haven't seen any of your tests yet that doesn't have the vertical bar that scrolls across.


The vertical bar i was thinking its the frequency of the torch but then why isn't it in the sweep sync adjustment tests they look clean ..?


Well the bottom of the sync bar will be flat only because that's the trigger for the start of the line - but the top of the sync bar will be jagged NOT because of the sync width (which IS fine BTW) but because your disk speed is varying - if you look at your wave files WITHOUT sync processing you will see the sync bar being a great wavy thing - this is disk speed variation - something you haven't addressed yet.


Ok gary getting ahead of my self but looked like again i did a better job on the sweep tests .

There is SLIGHT jaggedness on both sides of my avi's because the time base correction has changed the length of the sync pulse to make all lines in the video signal the same length (i.e. correcting the line length variation due to speed variations). But I can only do this to a 1 pixel resolution without greater oversampling (perhaps I should do that actually).



This sounds like another problem for the crystal motor control its cause you a lot of work to correct the lines .


Yes I think it must be something external as it is at none of the internal frequencies - but it is much lower now than it used to be.


I will track it down but i know i have forgotten to switch off the lap tops PS so i hope its just that !


Yes, that's the first time I have actually recognised it - so that's a big step forward.


Yes its easy for me as i know what i did so i know what to look for i need the distance i was doing stuff to close ,you viewer is a big help asi can line it up so at least i know the distance is right .

And yes, NBTV work is good for us... keeps us off the street :-)


Not me i am still looking for a old microwave oven ; )

And anyway, I think you are now one of a surprisingly small number of NBTVA members who have created a recognisable TV picture mechanically - well done!

:wink: [/quote]

Gary when i took this on i was thinking this was easier than a monitor but theres a bit to it your advice has made it easier!!!!but well worth the build more i try more i like it as we have talked about i have the camera bug now to.
The getting an image you can work out poor as my attempts are for me its really thrilling and i just want to do better more i play with it .
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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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