The PMT in control of the Devil

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Re: The PMT in control of the Devil

Postby Harry Dalek » Sat Jul 15, 2017 11:26 pm

Steve Anderson wrote:As I mentioned, the original ramp generators are not really designed for multi-frequency work without a lot of capacitor and resistor switching. Have a look at the circuit diagram of an analogue oscilloscope timebase. You'll see what I mean.


Yes Steve i was sort of expecting to do this i put in the connections for the caps solder desolder i could remove and test various capacitors with the various clock frequencies and use a multi switch when i know what caps are needed.

It is very easy to do this with a small 14-pin DIL microcontroller but I guess that's maybe not the way you wish to go. It measures the input frequency and sets the charge current of the capacitor such that it's a constant amplitude whatever the frequency. It would be no harder than using a 74HC00.

For the time being perhaps some thought needs to be put into this without using a micro.

Steve A.
[/quote]

Well the idea at the moment is to sync the sawtooth oscillators another way would be may be just convert the clock square wave direct to a a sawtooth and amplify it .i suppose just see how it gos as is ....the other way you just mentioned i didn't know about ,just like to use what i have handy and what works i have no dislike of any idea just what i can do what works it makes it more satisfying when i use what i have laying around like those multi position switches.
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 » Sun Jul 16, 2017 4:07 pm

I have a problem with syncing the sawtooth oscillators not to the frequency but it distorts the waveform at test point pin 3 of the lm311 .
photo 1 is the free running frame saw tooth oscillator at pin 3 of the lm311 now inputting the 50 hz from the 4060 to 6E the saw signal drops and distorts a touch at photo 2 ....photo 3 adjusted the little scope to 0.5 div so i could see the frequency meter if signal is to low that drops out but as you see its synced to the clock at 50hz.
i tried ac coupling caps dc coupling via resistance's up to 1.5meg at 1meg it still distorts it ...head scratching time !
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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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Re: The PMT in control of the Devil

Postby Steve Anderson » Sun Jul 16, 2017 5:27 pm

Yep, this doesn't surprise me. I'm not sure what to say except really it's best to start over, it's a bit like trying to get a dog to walk on its hind legs.

Not sure what to suggest at the moment, maybe others will come forward with ideas. For me I would go the microcontroller path and forget the analogue approach. But I understand if you don't want to go that route.

If I had more time currently I would be happy to spend some time on this, but right now I can't. A large two year project in Hong Kong beckons.

Steve A.
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Re: The PMT in control of the Devil

Postby Harry Dalek » Sun Jul 16, 2017 6:46 pm

Steve Anderson wrote:Yep, this doesn't surprise me. I'm not sure what to say except really it's best to start over, it's a bit like trying to get a dog to walk on its hind legs.

Not sure what to suggest at the moment, maybe others will come forward with ideas. For me I would go the microcontroller path and forget the analogue approach. But I understand if you don't want to go that route.

If I had more time currently I would be happy to spend some time on this, but right now I can't. A large two year project in Hong Kong beckons.

Steve A.


Thats Ok Steve i will have a think about it ,theres always another road to the same place just trying something else at the moment .
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 Klaas Robers » Sun Jul 16, 2017 9:30 pm

Why not replacing the saw tooth generator by a 4040 with a resistor D-A converter? Then, when you switch the input of the 4040 to a higher tap of the 4060, the sawtooth / fine stair case, goes twice as fast / slow. And you are only interested in steps of a factor of 2 ? At least for the frame this is a good idea, nobody will see the difference between a sawtooth and a staircase. And there is no fly back problem.......
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Re: The PMT in control of the Devil

Postby Harry Dalek » Sun Jul 16, 2017 11:17 pm

Klaas Robers wrote:Why not replacing the saw tooth generator by a 4040 with a resistor D-A converter? Then, when you switch the input of the 4040 to a higher tap of the 4060, the sawtooth / fine stair case, goes twice as fast / slow. And you are only interested in steps of a factor of 2 ? At least for the frame this is a good idea, nobody will see the difference between a sawtooth and a staircase. And there is no fly back problem.......


Hi Klass

I do have a 4040 handy this i would never of thought of being digital dummy ,i think i understand the process looking at the PDF resistors giving the stair case copy of a sawtooth i am not overly sure of the resistor values for each pin an example something like the below for the out put pins to make the stair case a few values a touch off make it easier not sure how fussy a half an ohm makes to the staircase waveform .
R1 384 k 800k
R2 192 k 400k
R3 96 k 200k
R4 48 k 100k
R5 24 k 50k
R8 12 k 25k
R9 6 k 12k
R10 3 k 6k
R11 2 k 3k
R12 1 k 1.5K

If you mean Klass i am just using double the line and in the frame case 12.5 25 and 50 hz yes gets a bit more complex i suppose wanting correct system line rates others have used ,i am not to bothered this time as its a bit of a learning exercise....having the 3 frame rates makes it interesting to me and i suppose i would have some new line systems.
Thanks here for the help i will give it a go see if i can get it to work i will post up .
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Re: The PMT in control of the Devil

Postby Klaas Robers » Mon Jul 17, 2017 2:04 am

Indeed , this is a nice document to get you familiar with this way of working. Read it, reread it, start an experiment, measure the results and you will see that you get used to it.
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Re: The PMT in control of the Devil

Postby Steve Anderson » Mon Jul 17, 2017 7:38 pm

The more I think on this the more sane a micro looks for when using multiple timebase frequencies.

Now for standard NBTV the frame sync is the 'missing pulse' system. But for other standards the frame sync would need to be defined. It could still be the 'missing' pulse' system or use one line for frame sync. Either way it's quite easy and within the capabilities of all here to build. You don't need to know what goes on inside the micro, it just does the business. No harder to build than using any 14-pin chip, no crystals, no EPROMs, none of that mucking around.

I need to think on this further, but it's definitely worth dwelling upon.

Steve A.
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Re: The PMT in control of the Devil

Postby Harry Dalek » Mon Jul 17, 2017 8:28 pm

Klaas Robers wrote:Indeed , this is a nice document to get you familiar with this way of working. Read it, reread it, start an experiment, measure the results and you will see that you get used to it.


I have used the idea with a 4017 for a SSTV grey bar test card generator ,using the idea to make a sawtooth signal very interesting ,I have a 4020 and many 4060,s same sort of counter .
i would of thought it would cause the scan line be a gagged bit bumpy but you say not i believe you than my theory but it will be interesting to see .
I started again here 4040 in place
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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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Re: The PMT in control of the Devil

Postby Harry Dalek » Mon Jul 17, 2017 9:19 pm

Steve Anderson wrote:The more I think on this the more sane a micro looks for when using multiple timebase frequencies.

Now for standard NBTV the frame sync is the 'missing pulse' system. But for other standards the frame sync would need to be defined. It could still be the 'missing' pulse' system or use one line for frame sync. Either way it's quite easy and within the capabilities of all here to build. You don't need to know what goes on inside the micro, it just does the business. No harder to build than using any 14-pin chip, no crystals, no EPROMs, none of that mucking around.

I need to think on this further, but it's definitely worth dwelling upon.

Steve A.


Microcontrollers i can see little that i know about them you have to program them yes ,i can see you could get it to do any line frame rate with in its limits with how well you can program it ...i have pretty much zero experience with these and programing
You will have explain your idea i will try and read up on them .
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 Andrew Davie » Mon Jul 17, 2017 9:36 pm

Harry Dalek wrote:
Steve Anderson wrote:The more I think on this the more sane a micro looks for when using multiple timebase frequencies.

Now for standard NBTV the frame sync is the 'missing pulse' system. But for other standards the frame sync would need to be defined. It could still be the 'missing' pulse' system or use one line for frame sync. Either way it's quite easy and within the capabilities of all here to build. You don't need to know what goes on inside the micro, it just does the business. No harder to build than using any 14-pin chip, no crystals, no EPROMs, none of that mucking around.

I need to think on this further, but it's definitely worth dwelling upon.

Steve A.


Microcontrollers i can see little that i know about them you have to program them yes ,i can see you could get it to do any line frame rate with in its limits with how well you can program it ...i have pretty much zero experience with these and programing
You will have explain your idea i will try and read up on them .


Arduino is pretty easy and I'd be happy to help where I can. That might be in holding your hand while you learn, or it might be actually writing the software for you. Just let me know. I can have you up and running with Arduino pretty quickly - it's really not that complex! I don't know what sort of frequency you need stuff done at, but I have some interrupts running at 187KHz on my televisor.
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Re: The PMT in control of the Devil

Postby Harry Dalek » Mon Jul 17, 2017 10:03 pm

Andrew Davie wrote:Arduino is pretty easy and I'd be happy to help where I can. That might be in holding your hand while you learn, or it might be actually writing the software for you. Just let me know. I can have you up and running with Arduino pretty quickly - it's really not that complex! I don't know what sort of frequency you need stuff done at, but I have some interrupts running at 187KHz on my televisor.


Thanks Andrew
Have to see what Steve has on he's mind when he has time i don't know how complex the Ic has to be ,i would think it needs programing so a circuit hooked up to the pc to program the thing .
Not sure have to wait and see ...in the mean time i will test the 4040 when done i would think it would still need a way to generate a sawtooth .
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 Steve Anderson » Mon Jul 17, 2017 10:13 pm

Likewise to Andrew's offer, I'm quite happy to send you some pre-programmed example PICs, they don't cost nothing, but they are cheap. I tend to buy a quantity for my 'real work' so the costs could be hidden amongst that. So don't worry about it.

I'm interested in doing this for myself as well as helping others out. It would be no different than buying a 4060, wiring it up and tuning for maximum smoke! It may be possible to get this down to an 8-pin package, no different to a 741. At worse a 14-pin package like a 7400.

But...the various standards required for frame, line, line sync and frame sync need to be defined. You can't expect it to lock to any old waveform.

With just 32 lines I understand the reasoning behind the 'missing sync' system, but when you get to above 48 lines one line dedicated to frame sync and possibly AGC is not noticeable. i.e. half the line dedicated to frame sync, the other half set to black which won't (shouldn't) be visible and potentially used for gain-setting and proper black-level clamping. Something sorely missing in the NBTVA standard. Also a front and back porch to negate sync-width modulation which is why all FSTV standards have them.

Steve A.
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Re: The PMT in control of the Devil

Postby Harry Dalek » Mon Jul 17, 2017 10:38 pm

Steve Anderson wrote:Likewise to Andrew's offer, I'm quite happy to send you some pre-programmed example PICs, they don't cost nothing, but they are cheap. I tend to buy a quantity for my 'real work' so the costs could be hidden amongst that. So don't worry about it.

I'm interested in doing this for myself as well as helping others out. It would be no different than buying a 4060, wiring it up and tuning for maximum smoke! It may be possible to get this down to an 8-pin package, no different to a 741. At worse a 14-pin package like a 7400.

But...the various standards required for frame, line, line sync and frame sync need to be defined. You can't expect it to lock to any old waveform.

With just 32 lines I understand the reasoning behind the 'missing sync' system, but when you get to above 48 lines one line dedicated to frame sync and possibly AGC is not noticeable. i.e. half the line dedicated to frame sync, the other half set to black which won't (shouldn't) be visible and potentially used for gain-setting and proper black-level clamping. Something sorely missing in the NBTVA standard. Also a front and back porch to negate sync-width modulation which is why all FSTV standards have them.

Steve A.



Thats very kind of you Steve i see your thinking behind it now ,i can see the difference of being stuck with the double the frequency of the 4060 to many other standards you could program the chip to do ..if anything the the 4060 at the moment lets me test what i am working on can always leave space or convert the circuit around the ic socket to the new chip if it comes about ...but yes interesting
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 Jul 19, 2017 8:44 pm

I knocked up a version of the 4060 circuit pretty much only the resister ladder on this one , i made a mistake as to Q0 i started the ladder on one and ended on the 12th output so i will have disconnect the resistors to the ic and reconnect view on the scope one at a time ,was not sure why most circuits just show 10 outputs when there are 12,my little scope is a touch slow for this work in put to the 4060 was 25hz pin 9 gave this result..
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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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