Questions tagged [crt]
Anything related to Cathodic Ray Tubes (CRTs), i.e. specially built electronic vacuum tubes where an electron beam is focused and deflected on a phosphor-coated surface in order to display an image.
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What does a grid-cathode bypass capacitor on CRT do, and why is this one not doing it?
I have modified a (US) 1970s solid state B&W TV set for direct (NTSC) composite input for vintage computer use, in accordance with some equally vintage instructions specific to this set. The set ...
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CRT vertical deflection problem
I'm getting an odd CRT problem.
When cold, the tube has an area about 1/3 way down that isn't scanned. The area above is compressed and the area below a little stretched.
I've attached 2 pictures - ...
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Can I use ceramics instead of electrolytic capacitors in CRT drive circuit?
I've been recapping an Amstrad PCW 9256 computer.
All the electrotyics are bad on the analogue board - I've replaced the electrolytics I have in stock and the CRT is now working almost perfectly but ...
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Can someone please explain this circuit? SMPS, Bridge Rectifier, Transformer
What do these optional components do?
Schematics: https://crtdatabase.com/crts/jvc/jvc-bm-h1300su
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Vertical wobble and flicker on analog oscilloscope
I'm using an old analog oscilloscope (Metrix ITT instruments OX 725).
(I don't have a printed manual for it, but you can find scans of a French user's manual and service manual (with circuit diagrams) ...
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Can a CRT last 100,000 hours or even 300,000?
Online, I could find that high-quality cathode-ray-tube displays (whether be it for a computer monitor or a television set) have a design lifespan of 30,000-50,000 hours of cumulative operation. I ...
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Why do CRT TVs need a HSYNC pulse in signal?
Could someone, please, explain how old CRT TVs reacted to input signal, specifically to VSYNC and HSYNC pulses?
Do these pulses control the electron beam? For instance, if signal would consist only of ...
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Silver Coating on the front glass inside a crt
I recently disassembled a defective Macintosh SE. When taking apart the CRT (safely) to preserve the front glass panel to screw back in, i noticed a silver coating on the inside of said front glass ...
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How did analog color televisions "fix" alignment problems in three-gun systems?
I recall my grandfather panicking when I attempted to adjust the tint on his TV. He said that he would have to call the TV people to come and re-align it. I thought he was crazy at the time, but later ...
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Circuit for horizontal and vertical amplifier, homemade oscilloscope
I want to make an oscilloscope with a small black and white TV (crt), currently disconnect the horizontal coil and with this circuit I can see the signals.
The problem with this is that only one half ...
user330326
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Can several CRTs be wired in parallel to one oscilloscope circuit?
I would like to make a 4 channel oscilloscope to view all 4 audio outputs of a quadraphonic amplifier. I can cheaply get 4 of the same type of oscilloscope but would like to have four CRTs side by ...
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Component requires specific voltage and current but the math doesn't add up
I'm trying to get an old soviet era cathode ray tube working.
On the data sheet it says the heating element needs between 5.7V and 6.9V, and between 0.54A and 0.66A, but I've measured the resistance ...
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Analog oscilloscope trouble
I recently purchased an old HP 130B oscilloscope. While I have experience with old analog oscilloscopes, I have run into an issue with this particular model and before I break anything breaking into ...
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Why are the vertical deflection coils in a CRT deflection yoke so different from the horizontal coils?
Looking at a typical raster CRT deflection yoke, there appear to be two very different pairs of coils. There is the pair on the inside that curves outwards, and the pair on the outside, which are ...
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How were the phosphors applied to the inside glass tube of older colour CRTs?
I've been reading into how CRTs were assembled and how they work, but I can't seem to find any concise information behind how the coloured phosphors inside the inner glass tube were applied. There is ...
