NBTV Television Analyst

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Re: NBTV Television Analyst

Postby Steve Anderson » Thu May 07, 2020 6:32 pm

Harry, how are you planning to scan the image? I've seen no mention of scanning discs or any other arrangement. A PMT is not a camera tube per se, like a vidicon, plumbicon or other tube that usually require deflection (magnetic) yokes. Nor are they designed for that. A flying spot camera is a possibility I guess, but there's been no mention of that so far either.

Yours quizzical of Bangkok.

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Re: NBTV Television Analyst

Postby Harry Dalek » Thu May 07, 2020 8:38 pm

Steve Anderson wrote:Harry, how are you planning to scan the image?


Hello Sensei Steve :wink:

Well the heading does says it all a Television Analyst but that's me because i have an interest in them it's a CRT Flying spot scanner out putting its test card video for setting up to adjust television monitors ...not making exactly the same thing idea as the original name sake and i have a monitor in the case as well as the Flying spot scanning CRT and its NBTV its possible perhaps might output higher line rates than even the B and K version thanks to your inventing ...but i will say NBTV for now ..i don't know if the VCR139A is capable of a small enough dot for a correct raster scan at the higher line rates so i will be happy with NBTV

Due to the placement space in the case i will end up using a mirror to reflect the flying spot screen of the transparency on it ..if i had space i would focus the flying spot raster on an image and the PMT would pick that up ..but i think i don't have space for the optics so that's on the back of my mind we will see .

BTW notice in the link if you look at the PMT in the Television Analyst case how close it is to the power supply transformer ! must not effect it

google link to B and K TV Analysts and such below
https://www.google.com/search?q=BK+Prec ... e&ie=UTF-8


I've seen no mention of scanning discs or any other arrangement.


No not this time Steve all electronic ..you cup of tea infact .

A PMT is not a camera tube per se, like a vidicon, plumbicon or other tube that usually require deflection (magnetic) yokes. Nor are they designed for that. A flying spot camera is a possibility I guess, but there's been no mention of that so far either.


Yes sir that's it Flying spot ..i spent the day wiring the PMT OMG i should of just lined up the resistor chain and wired the PMT from that ,i went the harder way double taking every connection wiring the resistors up one by one arr will not do that again i don't like it .

I will have to run it in and test it
OH i Have a quiz for you today what in the photo used belong to you ?
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Re: NBTV Television Analyst

Postby Steve Anderson » Thu May 07, 2020 8:53 pm

Remember that PMTs are generally blue sensitive rather than the red/I.R. of silicon. So whatever you plan plan to scan, bathe it in blue light...or bright daylight...forget tungsten...or fluorescent which have a really weird balance of output colours, but our eye/brain system seems to compensate quite well with that though. But maybe not PMTs. Our sun is considered a 'yellow dwarf', but it's output, sitting here at nearly 40C and 93 million miles away, is enough thank you! I'm glad I'm not on the surface of Venus right now!

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Re: NBTV Television Analyst

Postby Harry Dalek » Fri May 08, 2020 6:06 pm

Steve Anderson wrote:Remember that PMTs are generally blue sensitive rather than the red/I.R. of silicon. So whatever you plan plan to scan, bathe it in blue light...or bright daylight...forget tungsten...or fluorescent which have a really weird balance of output colours, but our eye/brain system seems to compensate quite well with that though. But maybe not PMTs. Our sun is considered a 'yellow dwarf', but it's output, sitting here at nearly 40C and 93 million miles away, is enough thank you! I'm glad I'm not on the surface of Venus right now!

Steve A.


It is amazing how much UV light comes from the sun any thing uv sensitive phosphorescent sure does glow bight exposed to day light i have a sky light in the roof of my shed my P7 monitor glows at night due to this .

Reason i never worried about the UV thing as the same PMT type worked with a green phosphor scope but if it was seeing the green phosphor raster or part of it i am not sure as the CRT might be emitting UV a small amount ? Old Crt Televisions did emitted small amount of UV as far as scope tubes i don't know but it would not take much for a PMT to see it .

Today i worked a bit more on the monitor mounted the flying spot CRT VCR139A brightness control which the 3BP1 is sharing at the moment and mounted another switch for the VCR139a's Heater ..it blocks a hole in the case and is right next to the 3Bp1s double purpose ..
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On the PMT side my plan is to run it in using the monitors or my custom made PMT HV negative supply from last time around .. mounted some sockets on a tin HV negative Ground and signal out of the PMT which i hope will be light proof i will check the sockets plastic as some times things like that can be bit transparent i will get a laser out and see if any thing gets in from the out side ,if all good next week i will fire it up and watch noise on the scope ...i might not have time next 2 days and work so it will be a while any ways see how it go's and i will post up when i do 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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Re: NBTV Television Analyst

Postby Steve Anderson » Sat May 09, 2020 4:49 pm

Harry, somehow I totally missed your posting on Thursday (the 7th)...and it's not exactly a small one!

Interesting bit of test gear, not seen anything quite like that before. Quite 'quirky' really. Its advantage over a monoscope is the interchangeable slides. A monoscope can only generate a single pattern and that's yer lot!

https://en.wikipedia.org/wiki/Monoscope

Today it simply would be stored in a memory and read out to generate the video signal. A 405-line version is here:-

http://www.thevalvepage.com/projects/te ... stcard.htm

For 525/625 use it would need a bit of rearranging for the different line and scan rates and a bit more memory. Ralph Taggart's ROM-scanner for NBTV/SSTV is based on the same principals. Doubtless a search through the BATC site would turn up others in all sorts of formats. I think Klaas has done one specifically for NBTV.

I think I may recognise those brown caps from the past! Good to see them put to use.

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Re: NBTV Television Analyst

Postby Harry Dalek » Sat May 09, 2020 6:06 pm

Steve Anderson wrote:Harry, somehow I totally missed your posting on Thursday (the 7th)...and it's not exactly a small one!


Thats Ok i had a bit in that one .

Interesting bit of test gear, not seen anything quite like that before. Quite 'quirky' really. Its advantage over a monoscope is the interchangeable slides. A monoscope can only generate a single pattern and that's yer lot!


Below a link i found on what happened and how the original art work used for the for the indian head used in its monoscope ...could of been lost .


https://web.archive.org/web/20150615014 ... /p4788.htm



Yes reason the thing interested me i have never seen or come across information on the Analyst device till a few years ago and it has always fascinated me...i am not sure there were ever 625 line versions ? but an interesting way to get a test card and change them for setting up you television monitor ...the easy way to change the test card is what i like .

https://en.wikipedia.org/wiki/Monoscope

Today it simply would be stored in a memory and read out to generate the video signal. A 405-line version is here:-

http://www.thevalvepage.com/projects/te ... stcard.htm

For 525/625 use it would need a bit of rearranging for the different line and scan rates and a bit more memory. Ralph Taggart's ROM-scanner for NBTV/SSTV is based on the same principals. Doubtless a search through the BATC site would turn up others in all sorts of formats. I think Klaas has done one specifically for NBTV.


Yes all done by digital circuits as in what you plan to design and mentioned for slow scan and NBTV but its nice to try the older ways as well as you see below the mono scope idea is interesting but you would have to change the whole crt to change the test card ...here's some interesting different ones as well i found in the past
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1938 France
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Not sure of the history of this tube with the lady below

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?
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Dumont "Phasmajector" cathode ray tubes
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82387422_10222128476740575_8791795486521556992_o.jpg


I also have a photo for a Baird 240 line monoscope but he call it something else to track it down ...i will post up when i find it .

I think I may recognise those brown caps from the past! Good to see them put to use.


Yes sir you got it right ! they came in very handy here !

As i thought i had no time to lay hands on the project today tomorrows worse but i am itching to power up the PMT
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: NBTV Television Analyst

Postby Steve Anderson » Sat May 09, 2020 6:52 pm

Harry Dalek wrote:....but i am itching to power up the PMT


Don't forget to keep it in the dark, PMTs do not like what you and I might call 'normal illumination'.

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Re: NBTV Television Analyst

Postby Harry Dalek » Sat May 09, 2020 8:20 pm

Steve Anderson wrote:
Harry Dalek wrote:....but i am itching to power up the PMT


Don't forget to keep it in the dark, PMTs do not like what you and I might call 'normal illumination'.

Steve A.


I am even checking the plastic socket connections in case they are some how transparent to some extent ..i would not be to worried at low voltage but running it in at the high end ! i might do what you did as well some time back and put some foil over it just in case ...so yes it will be light proof all it will be picking up is cosmic rays ....i think this noise should go up and down when we are sun side or not .
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: NBTV Television Analyst

Postby Harry Dalek » Fri May 15, 2020 5:57 pm

Unfortunately after firing up the PMT and 2 days of testing it didn't seem light sensitive at all the wiring resistor chain and amplifier seemed fine ,i double checked with a working PMT on another circuit it worked so the power supply is fine , so i have taken another approach and rebuilt the resistor chain so i can avoid this problem again so if the Next tube works i can double check this PMT with out to much trouble and know for sure its had it or not ..i have no history for it apart from it was used by some one else ...it came a lot of 6 or 7 only one i have had a problem with so far .

Any case i will try the next PMT and see what happens tomorrow .

Edit...this one seems to work testing it this morning
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Re: NBTV Television Analyst

Postby Harry Dalek » Sat May 16, 2020 5:48 pm

I was to make up my mind here as to options use transparencies or not but the test below i could replace the screen with a mirror remove the lens here the slide idea still works ..i was only using a slide to test screen focusing so perhaps this is the way i should mount the flying spot CRT i could try photos and slides with some adjustments mentioned /
The CRT back to the Transformer does not seem to effect it nothing on the flying spot side is mounted for good but today i think i like this positioning best .


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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: NBTV Television Analyst

Postby Klaas Robers » Sat May 16, 2020 7:59 pm

For proximity focus in this arrangement:
- place the picture slide as close as possible to the CRT-screen,
- place a 90 degree mirror where you have now the screen.
- A glass mirror with the silver layer at its back may give ghost pictures due to internal reflections,
- so a surface silvered mirror is preferred,
- but difficult te get hold on.
- Place the PMT aside the other CRT,
- give it a light thight hood with a small viewing hole (pin hole).
- experiment with the size of the pinhole,
- the smaller, the better focus, sharper picture,
- but the less light.
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Re: NBTV Television Analyst

Postby Harry Dalek » Sat May 16, 2020 9:06 pm

Klaas Robers wrote:For proximity focus in this arrangement:
- place the picture slide as close as possible to the CRT-screen,
- place a 90 degree mirror where you have now the screen.
- A glass mirror with the silver layer at its back may give ghost pictures due to internal reflections,
- so a surface silvered mirror is preferred,
- but difficult te get hold on.
- Place the PMT aside the other CRT,
- give it a light thight hood with a small viewing hole (pin hole).
- experiment with the size of the pinhole,
- the smaller, the better focus, sharper picture,
- but the less light.


Thanks for the tips here Klaas
OK i will work on mirror idea more than likely have to use a glass mirror but i might have a plastic mirror laying around either way i can see what will be the result with a glass one .
I still a bit to do ... hook the PMT video to the viewing CRT's opto same syncing both crt's so no need for any thing here but i am going to output a video signal but i can worry about that after i get an image on the Analyst's crt screen
I have to take the negative supply and drop it to a few hundred volts i want to adjust this up to it starting to work as i recall these are pretty fussy on the correct voltage , i don't think it will be more than- 600 at most i expect lower 300 400v for off CRT screen transparency as i recall it was around this for the last flying spot CRT go few years back .
But i will work on a cover and try the small hole for the PMT see how that gos ...it must work on the PMT NIpkow camera i made that's sort of the same idea .
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: NBTV Television Analyst

Postby Harry Dalek » Wed May 20, 2020 3:56 pm

Have not posted a while all going well here i should be able to hook up the PMT to the circuit that will drive the opto coupler next few days .
I found a nice new plastic mirror for the reflection to the PMT knew it would come in handy one day fits just right .
So give me a day or 2 and i will fire it up and post up .
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: NBTV Television Analyst

Postby Steve Anderson » Wed May 20, 2020 5:19 pm

Likewise, not posted myself for a while, it's simply become too hot here to do anything, over 40 Celcius outside. Lethargic is the word. Nice white puffy clouds in a azure blue sky, but not a drop of rain...and this is supposed to be the wet season! If there were flights to Europe I might be tempted...or even Oz as it's their winter...I guess I miss those years I lived in Victoria...

Steve A.

The sky is actually a much deeper blue, getting on towards black, but I guess the phone doesn't have a UV filter...

Don't get me wrong, I wouldn't swap those dull dismal winter days in the UK where it hovers in single digits seemingly forever...no thanks..air-con is a lot cheaper to run than heating a house in the UK...
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Re: NBTV Television Analyst

Postby Harry Dalek » Wed May 20, 2020 10:56 pm

Steve Anderson wrote:Likewise, not posted myself for a while, it's simply become too hot here to do anything, over 40 Celcius outside. Lethargic is the word..



I have noticed this problem The summer winter thing no matter where you are as in it really does stuff the project doings up .
Since most of my stuff is in the shed if its to hot of too cold you really do not feel like working there... when it gets towards winter or summer i just move it on the study table in the house or i would never get any thing done .

Back on the Analyst Project i will work onit tomorrow getting to the interesting part now .

Edit ... it is now tomorrow and gave the circuit to the opto coupler to the monitor a go feeding its circuit some video its showing inverted and of cause not in sync or close at least so the drift showing .
i need to get this right before moving on to the pmt ,i will try a few things today i think i am just inputting the opto coupler circuit wrong spot from another circuit .any case this was the first result might have to add a video inverting input to this circuit either way i am not sure what i will get out of the PMT so that would be helpful to get right now .
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Last edited by Harry Dalek on Thu May 21, 2020 11:33 am, 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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