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lurscher
Joined: 27 Nov 2013
Posts: 2
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| Posted: Wed Nov 27, 2013 8:32 pm Post subject: CRT tube for physical experiment |
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Hi,
I want to adquire some high-intensity CRT projector tubes for doing a physics experiment. The problem is that I need to steer the electron beam at MHz frequencies (about 500Mhz if my preliminary estimations are right). I'm considering that buying one should be cheaper than building one from scratch, but I'm concerned that the high FM voltages in the steering coils would produce a lot of self-inductance heat and burn them, so I'm wondering if there are commercial electrostatic-driven CRT tubes out there on the market
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gjaky
Joined: 05 Jun 2010
Posts: 2802
Location: Budapest, Hungary
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| Posted: Wed Nov 27, 2013 9:42 pm Post subject: |
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how do you mean that 500MHz vertical or horizontal deflection or is that would be the pixel clock?
Old analog scopes had trickey distributed deflection plates (electrostatic deflection) but those topped at around 400MHz in vertical speed. With standard coils and magnetic deflection I would think that is pretty hard to do achieve...
_________________
projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB, VIM-DB
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lurscher
Joined: 27 Nov 2013
Posts: 2
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| Posted: Wed Nov 27, 2013 10:42 pm Post subject: |
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| gjaky wrote: | how do you mean that 500MHz vertical or horizontal deflection or is that would be the pixel clock?
Old analog scopes had trickey distributed deflection plates (electrostatic deflection) but those topped at around 400MHz in vertical speed. With standard coils and magnetic deflection I would think that is pretty hard to do achieve... |
Indeed. The 500 Mhz would be over both directions, since this won't necessarily be sweeping in a raster mode, will be closer to the vector mode of oscilloscopes, but still the slew rate is determinant for the application.
I probably would have to manufacture the electrostatic coils myself, since they don't seem to be used anymore in CRTs. But I still want to buy the highest intensity cathode beam I can get at a reasonable price, or at least less than building my own.
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gjaky
Joined: 05 Jun 2010
Posts: 2802
Location: Budapest, Hungary
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| Posted: Wed Nov 27, 2013 11:11 pm Post subject: |
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Electrostatic deflection does not allow high density well focused beam, that's why there is the magnetic deflection, the other problem is with the static deflection is that you can't place them in one place this means one or other deflection pair will have greater distance between them making them assymetrical by 1:10 ratio in achievable deflection speed.
Hewlett-Packard, Tektronix and the other big companies sweatted blood to make tubes to achieve even 2-300MHz deflection speed, and that was the biggest secret in their whole design not the driving electronics. Sorry to say but I have great doubts in that you could draw a tube that does 500MHz in both directions, that's like a 5-10year development from zero...
Look at some old oscilloscopes and grab what's the best for your needs, otherwise it's a money pit...
one guess: Tektronix 485
_________________
projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB, VIM-DB
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the big E
Joined: 20 Apr 2013
Posts: 1928
Location: speedwell Tn.
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| Posted: Wed Nov 27, 2013 11:18 pm Post subject: |
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Op I have a projection tv tube with a yoke if you want it pm me its never been used
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crt king of black
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CasetheCorvetteman
Joined: 09 Nov 2008
Posts: 6326
Location: Australia
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| Posted: Wed Nov 27, 2013 11:38 pm Post subject: |
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What tube E?
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Barco Cine 9, ,Sony VPL570ES 4K SXRD, 135" OZ Theatre Majestic 16:9 screen, Denon X6700in preamp mode, 2x 7ch Tonewinner amps, 2x Tonewinner 15" subs, 2x 10" subs, 7.2.6...
RUNCO DTV991 LC ( NEC XG 852 LC ) 100" 4:3 screen, H/K AVR 7.1...
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the big E
Joined: 20 Apr 2013
Posts: 1928
Location: speedwell Tn.
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| Posted: Wed Nov 27, 2013 11:40 pm Post subject: |
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| CasetheCorvetteman wrote: | | What tube E? |
Its out of a projection tv I gutted a long time ago but never used for anything else its a 7inch vdc brand
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crt king of black
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CasetheCorvetteman
Joined: 09 Nov 2008
Posts: 6326
Location: Australia
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| Posted: Thu Nov 28, 2013 8:27 am Post subject: |
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| the big E wrote: | | CasetheCorvetteman wrote: | | What tube E? |
Its out of a projection tv I gutted a long time ago but never used for anything else its a 7inch vdc brand |
Colour and type?
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Barco Cine 9, ,Sony VPL570ES 4K SXRD, 135" OZ Theatre Majestic 16:9 screen, Denon X6700in preamp mode, 2x 7ch Tonewinner amps, 2x Tonewinner 15" subs, 2x 10" subs, 7.2.6...
RUNCO DTV991 LC ( NEC XG 852 LC ) 100" 4:3 screen, H/K AVR 7.1...
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the big E
Joined: 20 Apr 2013
Posts: 1928
Location: speedwell Tn.
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| Posted: Thu Nov 28, 2013 2:09 pm Post subject: |
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| CasetheCorvetteman wrote: | | the big E wrote: | | CasetheCorvetteman wrote: | | What tube E? |
Its out of a projection tv I gutted a long time ago but never used for anything else its a 7inch vdc brand |
Colour and type? |
Its blue I will look and see what number is on it some time today
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crt king of black
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CasetheCorvetteman
Joined: 09 Nov 2008
Posts: 6326
Location: Australia
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| Posted: Fri Nov 29, 2013 12:03 am Post subject: |
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Cheers mate, Aussie_Al might be interested for a Toshiba rear projection TV he has with a burned blue.
_________________
Barco Cine 9, ,Sony VPL570ES 4K SXRD, 135" OZ Theatre Majestic 16:9 screen, Denon X6700in preamp mode, 2x 7ch Tonewinner amps, 2x Tonewinner 15" subs, 2x 10" subs, 7.2.6...
RUNCO DTV991 LC ( NEC XG 852 LC ) 100" 4:3 screen, H/K AVR 7.1...
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the big E
Joined: 20 Apr 2013
Posts: 1928
Location: speedwell Tn.
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| Posted: Fri Nov 29, 2013 12:08 am Post subject: |
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Case I found out its a Panasonic 180 tube that was rebuilt by vdc its a 7 inch so if he wants it tell him for me I would be glad to get it out of my way since I no longer have a tv for it
My samsung uses p16 tubes and this one won't work with it as far as I know
It has the yoke and the anode feed both heck I even has a lens for it somewhere
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CasetheCorvetteman
Joined: 09 Nov 2008
Posts: 6326
Location: Australia
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| Posted: Fri Nov 29, 2013 6:14 am Post subject: |
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Ill send him a text message mate, cheers 
_________________
Barco Cine 9, ,Sony VPL570ES 4K SXRD, 135" OZ Theatre Majestic 16:9 screen, Denon X6700in preamp mode, 2x 7ch Tonewinner amps, 2x Tonewinner 15" subs, 2x 10" subs, 7.2.6...
RUNCO DTV991 LC ( NEC XG 852 LC ) 100" 4:3 screen, H/K AVR 7.1...
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the big E
Joined: 20 Apr 2013
Posts: 1928
Location: speedwell Tn.
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| Posted: Fri Nov 29, 2013 6:17 am Post subject: |
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| CasetheCorvetteman wrote: | | Ill send him a text message mate, cheers |
Thanks case let me know what he says
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CasetheCorvetteman
Joined: 09 Nov 2008
Posts: 6326
Location: Australia
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| Posted: Fri Nov 29, 2013 8:08 am Post subject: |
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Could take a while, he isnt always the quickest to return messages these days!! 
_________________
Barco Cine 9, ,Sony VPL570ES 4K SXRD, 135" OZ Theatre Majestic 16:9 screen, Denon X6700in preamp mode, 2x 7ch Tonewinner amps, 2x Tonewinner 15" subs, 2x 10" subs, 7.2.6...
RUNCO DTV991 LC ( NEC XG 852 LC ) 100" 4:3 screen, H/K AVR 7.1...
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the big E
Joined: 20 Apr 2013
Posts: 1928
Location: speedwell Tn.
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| Posted: Fri Nov 29, 2013 4:38 pm Post subject: |
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| CasetheCorvetteman wrote: | | Could take a while, he isnt always the quickest to return messages these days!! |
I can wait as I have had that tube for years
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digitalayon
Joined: 02 Mar 2009
Posts: 921
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| Posted: Tue Dec 03, 2013 7:21 pm Post subject: |
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do not forget to spray the thing with water as you try this!!!!
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DEADCRT
Joined: 15 Jun 2007
Posts: 13
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| Posted: Sat Dec 07, 2013 7:11 pm Post subject: |
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Hello,
gjaky is rigth. For such deflection speeds only way is use of electrostatic deflection tube. They were used in analog osciloscopes.
This type of deflection had low deflection angle ( for good linearity ) , so tubes were long.
As I remember, I have old russian scope with vertical bandwith 350 MHz. Type C1-75 . Some parameters you can find here
http://www.cqham.ru/hpa/osc_c1-75.htm
In some cases you can find , that it has only 250MHz bandwith.
I also saw analog scopes with ~6GHz bandwith . Scope with 350MHz bandwith was nothing special.
Of course, these tubes ( especially GHz range ) had very special design, we called it : running wave .
Brightness much lower than projection tubes.
For example this tube : http://radioreinhard.de/Roehren/Katodenstrahlroehren/13LO105M-russ.html
According to datasheet this tube has 3dB bandwith up to 500MHz, and up to 800 MHz with 5dB.
I have lot of datasheets of these tubes.
Of course you will find similar tubes produced in USA.
I also have lot of new Toshiba projection TV tubes.
I don't know your final goal, but may be these ideas will be useful . At least for reading with cup of tea 
Another way is deflect laser beam with Kerr cell.
http://en.wikipedia.org/wiki/Kerr_effect
Again, this method has very low deflection angle. But speed - anything you want.
One more way : use fast scope tube and ILA projector structure. I don't know about speed limitation in ILA plate.
http://www.google.lt/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&ved=0CDEQFjAA&url=http%3A%2F%2Fpro.jvc.com%2Fpro%2Fhjt%2Ftechnology%2Fdownload%2Fsid99.pdf&ei=LnKjUuWhII6BhAeDtYCwCA&usg=AFQjCNGH_2YLx21AzHZ7xUwBFDnj0ZanDA
Search keyword: ila projector technology crt
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