The PMT in control of the Devil

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Re: The PMT in control of the Devil

Postby Robonz » Fri Aug 25, 2017 9:15 pm

Harry, I am not that familiar with the circuit. The first stage looks good for sure. I don't know your electronics abilities so this may be obvious. Make sure you put a 0.1uF capacitor across pin 4 and 7 on (close to) each IC to keep the supply noise to a minimum, this will avoid false sync signals. Also add 47uF across the 12V on your circuit.

Cheers
Keith
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Re: The PMT in control of the Devil

Postby Harry Dalek » Fri Aug 25, 2017 10:26 pm

Robonz wrote:Harry, I am not that familiar with the circuit. The first stage looks good for sure. I don't know your electronics abilities so this may be obvious. Make sure you put a 0.1uF capacitor across pin 4 and 7 on (close to) each IC to keep the supply noise to a minimum, this will avoid false sync signals. Also add 47uF across the 12V on your circuit.

Cheers
Keith


I started working onit today theres a lot of ways to go on this project but i think making the video signal will finish off the PMT flying spot camera and i could test the video on the lower line rates pretty much plus record it post up and share .
The circuit is a club circuit i am pretty sure its one Klass has designed i have used it a few times last on the PMT nipkow camera last year and it worked fine on my modified version ...i used at first the transistor to pins 1 and 8 on ic 2 for the sync but found inputting to pin 2 via a 120k resistance dropping the sync pulse level it worked better .
Yes decoupling caps will be added to the circuit ....still have to add a monostable for pulse width control for correct sync width see if i can fit on the little board i am using ...
i had room on boards in the PMT case for this circuit but i need to test this out side the case for correct level adjustments then i can mount it inside .
Thanks for the advice i will reduce circuit noise .
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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Re: The PMT in control of the Devil

Postby Harry Dalek » Wed Aug 30, 2017 7:20 pm

I have not had much time to work on the project i just finished the video sync mixer just working the mono circuit for adding the sync pulses and width control of them i am going to use 2 74121 have those handy they will be on another little board..
I came across a good site on past TV system standards worth keeping the information
http://radios-tv.co.uk/Pembers/World-TV ... index.html
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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 PMT in control of the Devil

Postby Harry Dalek » Fri Sep 01, 2017 1:44 pm

Working on a sync pulse for each of the multi system line frequencies today with pulse width control to add to the video sync mixer
This solution here seems to work ...i was expecting to need switching for the monostable circuit which seems not i was testing various capacitors .
Testing the main circuit line frequency switch in the video and nice to see the circuit if following .
i am Ac coupling it but its not need here .

Testing the frame mono ic it works as well..


youtu.be/-tJt3jzJIqQ
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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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