Photomultiplier Tubes camera build

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Re: Photomultiplier Tubes camera build

Postby Harry Dalek » Fri Dec 16, 2016 7:20 pm

gary wrote:Harry for some reason, maybe it's lack of scale in the pictures, but that needle looks huge AND blunt!


Hi Gary
Yes looks blunt for sure with the usb micro scope sure shows a different picture of things ..metal of the needle look a bit ruff to ...

Its used so i would think a new one would be better and a smaller size pin needle might do a better job as Graham posted ,just wanted to see if i could make a smaller hole .

Might be a bit harder on some thing thicker like a cd dvd could suppose just drill larger holes and place stick a paper or foil Nipkow over it.
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: Photomultiplier Tubes camera build

Postby Viewmaster » Thu Dec 22, 2016 10:31 pm

Harry, not been following this too well nor any work on my machine
as wife broke hip and I am caring for her.......
.....But another way to get small perfectly round holes is to photograph a block of good
shaped larger holes using high contrast film (if you can get it?).
Then over develop it for max contrast. cut up the film using all the tiny hole images
to stick on the disc.

This should ensure that you have perfectly round (or any other shape you like) holes
that are VERY small. (choose a camera lens and shooting distance to suit)
“One small step for a man,"......because he has Arthritis.
Albert.
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Re: Photomultiplier Tubes camera build

Postby Harry Dalek » Fri Dec 23, 2016 8:45 pm

Viewmaster wrote:Harry, not been following this too well nor any work on my machine
as wife broke hip and I am caring for her.......


OH no sorry to hear about your wife Albert !

.....But another way to get small perfectly round holes is to photograph a block of good
shaped larger holes using high contrast film (if you can get it?).
Then over develop it for max contrast. cut up the film using all the tiny hole images
to stick on the disc.


I was just reviewing your THE NIPKOW NIPPER ...this morning just reviewing the making a tiny hole procedure ...i would try the film idea but its a bit costly over just making a hole i do have film camera but with my optics skills i don't think i would have much luck .

This should ensure that you have perfectly round (or any other shape you like) holes
that are VERY small. (choose a camera lens and shooting distance to suit)
[/quote]

I saw your jig with the camera really good idea .

I have put my camera back together with an amount of problems Gary knows about on the sync monostable 555 ...well i got that back to going ...and today i found my video sync mixer transistor looks dead the 2n2222....took me a while to track it down .
I found by putting a 1 meg resistor on pin 2 of the second ic at about 120k i could mix the sync with the video seemed to have better control as well ..theres a sight amount of noise i can see ...i can get betting shading but .
Heres my William again as a test subject ..sync is a touch off frequency framing out and such ...but first image after the disaster ...
EDIT
BTW Gary i found while this transistor is dead i can see the video out with no sync so i can i think i can test now a clean video signal via this circuit to see as if as we think the video is being a touch distorted on the horizontal lines .
Attachments
newsyncpin2Untitled.wav
(6.56 MiB) Downloaded 272 times
syncmix11 %282%29.gif
syncmix11 %282%29.gif (10.04 KiB) Viewed 5903 times
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: Photomultiplier Tubes camera build

Postby gary » Sat Dec 24, 2016 10:22 am

Harry Dalek wrote:BTW Gary i found while this transistor is dead i can see the video out with no sync so i can i think i can test now a clean video signal via this circuit to see as if as we think the video is being a touch distorted on the horizontal lines .


Yes at this stage the syncs (because of the waviness) are more trouble than they are worth - they do indicate something is not quite right but other than that they don't do anything so it is best to run without them - the problem may go away when you build your new disk.

In relation to that, however, one thing we didn't discuss (I don't think) is whether your disk is running perfectly concentrically - that is, is the side of the disk, taken at any position, always in the same position when you turn the disk? Or does it move back and forth, or up and down?

Placing some reference near the edge would give you a good indication of that.

In fact, it is more important (to what I am thinking) that the edge of the ENCODER is concentric to the disk, AND that the disk runs true.
gary
 

Re: Photomultiplier Tubes camera build

Postby Harry Dalek » Sat Dec 24, 2016 11:50 am

gary wrote:Yes at this stage the syncs (because of the waviness) are more trouble than they are worth - they do indicate something is not quite right but other than that they don't do anything so it is best to run without them - the problem may go away when you build your new disk.


Hi Gary i didn't see this message when i i was testing earlier on adjusting the sync i had it on full before adjusted it here in the wav file video ...but yes i see the wavy look when playing back ..i can disconnect it now i didn't know till i had this problem with the sync mixer transistor that your software would still play just the video signal on its own.

Sort of hard to keep focused on one problem at a time as i have a few i need to fix and i do jump about .

In relation to that, however, one thing we didn't discuss (I don't think) is whether your disk is running perfectly concentrically - that is, is the side of the disk, taken at any position, always in the same position when you turn the disk? Or does it move back and forth, or up and down?


It pretty much has to run true as we are talking a mm or less as it rotates in its case so i would think it is ...but ....i used a template placed over the disk to drill hole positions so it is more than possible for this to be i a touch off so wobble could be this a touch off perhaps ...

Placing some reference near the edge would give you a good indication of that.


Its the reason i like to use a dvd or cd as i reused the mounting connection left on the motor so the disk it pretty much spot on as it would have to have been when used in a cd or dvd player .

In fact, it is more important (to what I am thinking) that the edge of the ENCODER is concentric to the disk, AND that the disk runs true.
[/quote]

Well yes here to on the encoder centering in place.... i do this by eye and i know i could be a touch off here too and this would also cause a wobble in the sync as the encoder does taper down in size.
I will try and do a sync less test ....
Attachments
wiliam24thdec16Untitled.wav
William once again test subject
(10.77 MiB) Downloaded 293 times
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: Photomultiplier Tubes camera build

Postby gary » Sat Dec 24, 2016 1:24 pm

Harry Dalek wrote:Well yes here to on the encoder centering in place.... i do this by eye and i know i could be a touch off here too and this would also cause a wobble in the sync as the encoder does taper down in size.

Yes, I see you are with me on this, the trouble is that I can't see how the small amount of taper could cause such a large variation unless there was an enormous amount of run out, to the extent where the encoder segment would move from it's top to it's bottom - and even then I can't see that causing this much variation.

This is a mystery I would be very interested in getting to the bottom of.
gary
 

Re: Photomultiplier Tubes camera build

Postby Harry Dalek » Sat Dec 24, 2016 4:15 pm

gary wrote:
Yes, I see you are with me on this, the trouble is that I can't see how the small amount of taper could cause such a large variation unless there was an enormous amount of run out, to the extent where the encoder segment would move from it's top to it's bottom - and even then I can't see that causing this much variation.

This is a mystery I would be very interested in getting to the bottom of.

[/quote]

Hi Gary
Yep i understand and i can see what is more than likely happening with the encoder also wobble in and out a touch would cause the pulses to change size i suppose to ...i noticed some dvds wobble more than others the one i am using is pretty good there is wobble there when it looking for it ..it would be easy just to try a few encoders on some dvds cds and see the difference..

OK i tried to make a no Sync ....video only signal camera recording i see it plays better on the newer TBP than the old one viewing live i tried my best here iron cross as i could just see bits now and again but looks like it recorded fine apart from my speed is a bit off .

Second experiment was playing a nbtv VIDEO to pin 2 of the first video ic and recording what came out as pernormal from the camera video out the sync was disconnected as i just needed this circuit to test ....it looks to me like theres a slight wobble in the video edges i also see from video camera signal so may be its part of the cause ...
Any way i will record a few encoder gos and see what different encoders give ..
Attachments
nosync24.wav
This i removed the sync from the 555 mono to video sync mixer
(8.42 MiB) Downloaded 274 times
nosync24thvideotopin2.wav
here i played a nbtv wav file and connected it to pin 2 of the first ic video out as per nomal connection from camera
(3.77 MiB) Downloaded 267 times
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: Photomultiplier Tubes camera build

Postby gary » Sat Dec 24, 2016 4:53 pm

Harry Dalek wrote:OK i tried to make a no Sync ....video only signal camera recording i see it plays better on the newer TBP than the old one viewing live i tried my best here iron cross as i could just see bits now and again but looks like it recorded fine apart from my speed is a bit off .


Interestingly there seems to be a ghost of the old syncs in that video, could you do that test again with a test card that just has horizontal lines (or similar) please?

Harry Dalek wrote:Second experiment was playing a nbtv VIDEO to pin 2 of the first video ic and recording what came out as pernormal from the camera video out the sync was disconnected as i just needed this circuit to test ....it looks to me like theres a slight wobble in the video edges i also see from video camera signal so may be its part of the cause ...
Any way i will record a few encoder gos and see what different encoders give ..


Harry, that was an interesting experiment, but what were you playing the video out of as it seems to be slightly off in speed - if from another computer you are probably playing a 44.1kHz wave file - if so convert it to 48kHz and try again (most sound cards don't handle 44.1kHz accurately)
gary
 

Re: Photomultiplier Tubes camera build

Postby Harry Dalek » Sat Dec 24, 2016 6:29 pm

gary wrote:
Interestingly there seems to be a ghost of the old syncs in that video, could you do that test again with a test card that just has horizontal lines (or similar) please?


OK i will try Gary those Ghost syncs as you say were the cause of me not being able to see it off screen most of the time tried to adjust so it could see but i am mostly blind trying this ...did a line recording but i am not sure how well i did ? see ll wav.



Harry, that was an interesting experiment, but what were you playing the video out of as it seems to be slightly off in speed - if from another computer you are probably playing a 44.1kHz wave file - if so convert it to 48kHz and try again (most sound cards don't handle 44.1kHz accurately)


I tried but looks to roll more have to look into what i may have done wrong or try another computer ...so i will double check this when i can .
Attachments
ll.wav
(2.16 MiB) Downloaded 269 times
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: Photomultiplier Tubes camera build

Postby Harry Dalek » Sat Dec 24, 2016 7:11 pm

Gary heres 3 sync recordings from the opto reflector switch
i knocked together 2 others the disks are 1 is the nipkow i am using..... 2 does wobble and 3 with the missing sync wobbles too
that is in and out my Nipkow you can hardy see any ...they all have the same sort of wavy look .
All same encoder your last one i just stuck a missing sync in for testing .
Attachments
1.wav
(1.83 MiB) Downloaded 282 times
2.wav
(2.12 MiB) Downloaded 274 times
4.wav
(2.01 MiB) Downloaded 270 times
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: Photomultiplier Tubes camera build

Postby gary » Sat Dec 24, 2016 7:41 pm

Harry Dalek wrote:I tried but looks to roll more have to look into what i may have done wrong or try another computer ...so i will double check this when i can .


Something is very wrong Harry, the playback of the wave file is way out.

(Since you are posting 48kHz wave files I assume you are recording at 48 kHz?).
gary
 

Re: Photomultiplier Tubes camera build

Postby gary » Sat Dec 24, 2016 7:45 pm

Oh wait Harry, you are confusing me, II.wav isn't the 48kHz playback it's the horizontal line card - I get it - but Harry that one is so bad I can't tell if they are horizontal or vertical!
gary
 

Re: Photomultiplier Tubes camera build

Postby Harry Dalek » Sat Dec 24, 2016 9:53 pm

gary wrote:Oh wait Harry, you are confusing me, II.wav isn't the 48kHz playback it's the horizontal line card - I get it - but Harry that one is so bad I can't tell if they are horizontal or vertical!


That was the problem i was not sure it was off frequency or the card was at an angle ..sorry about that think that was the only one to come out but i will have a look at the others again ///i was a bit rushed today for time as well ...the camera is on its side so you have to angle the test card ..running blind i will redo the test now i know it was off .
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: Photomultiplier Tubes camera build

Postby Harry Dalek » Sat Dec 24, 2016 10:10 pm

gary wrote:Something is very wrong Harry, the playback of the wave file is way out.

(Since you are posting 48kHz wave files I assume you are recording at 48 kHz?).


Yes ///that was a video file the NBTV wav file showed up as 44.1 from memory or around there so you were right...i converted it to 48 seemed to be worse ..i will do it again theres another recording that looks good but i am not sure looks to good to me need to repeat the recording another time or 2 to make sure ..

Yes again recording at 48khz...or i try to remember each time i do it .

Should have more time after xmas hope you have a good xmas Gary and every one else here :mrgreen:
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: Photomultiplier Tubes camera build

Postby gary » Sun Dec 25, 2016 10:09 am

Harry Dalek wrote:
gary wrote:Something is very wrong Harry, the playback of the wave file is way out.

(Since you are posting 48kHz wave files I assume you are recording at 48 kHz?).


Yes ///that was a video file the NBTV wav file showed up as 44.1 from memory or around there so you were right...i converted it to 48 seemed to be worse ..i will do it again theres another recording that looks good but i am not sure looks to good to me need to repeat the recording another time or 2 to make sure ..

Yes again recording at 48khz...or i try to remember each time i do it .

Should have more time after xmas hope you have a good xmas Gary and every one else here :mrgreen:


A Merry Christmas to you and yours Harry!

(BTW just so we are on the same page - when I was talking about 44.1kHz I was referring to this file: nosync24thvideotopin2.wav - that was when you injected an NBTV test wave into your system which I thought was a very good idea but it is the original of that file (the one you injected) that needs to be made 48kHz - not the recording.)
gary
 

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