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Electron Gun from old CRT

Discussion in 'Buy, Sell and Trade' started by Dragon Tamer, Jun 28, 2010.

  1. Dragon Tamer

    Dragon Tamer Member

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    I took apart an old Compaq CRT monitor recently and wanted some of the parts off of the circuit board for my experiments. I'm left with an electron gun that has no power supply and is too big to fit into the trash can so I decided that I might sell it. I was wondering what something like this might sell for on average.

    If you are interested in buying it, that works just as well.
     
  2. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    Assuming you mean the CRT?, it's only worth something if someone wants that exact CRT for something - personally I would consider it worth nothing and just bin it - fully working CRT monitors are worthless these days.
     
  3. transistor495

    transistor495 Member Forum Supporter

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    Even if we give it for free, nobody want'em. Because no use and dumping is a problem.

    Actually I'm using a Samsung crt now. My worry is how to dump it before going for a TFT :)
     
  4. dave

    Dave New Member

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  5. mneary

    mneary New Member

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    Some states have an E-waste program that allows you to turn in old CRTs for safe disposal. If that's a color display, the glass has several pounds of lead which really doesn't belong in the landfill, rotting just above your water table. Look up E-waste in your local directory.
     
  6. Dragon Tamer

    Dragon Tamer Member

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    I was thinking that someone would want it to repair an old monitor if they're too cheap or lazy to buy a new one. (Imagine a 15" CRT screen on a laptop computer...) I did have the idea of using the CRT to make a cheap oscilloscope, but that seems unlikely for a lot of reasons.
     
  7. Diver300

    Diver300 Well-Known Member

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    You can't use a CRT to make an oscilloscope directly, as it won't deflect fast enough to view any waveforms over 100 kHz or so. Monitors and TVs with CRTs use magnetic deflection to get high deflection angles, making the tube short from front to back. However the inductance of the deflection coils makes high deflection rates impossible.

    Analogue oscilloscopes use electrostatic deflection, which allows much faster waveforms to be viewed, but the deflection angle is low, so that the CRTs are very long.

    Of course, a digital oscilloscope can use a slower display.
     
  8. Mikebits

    Mikebits Well-Known Member

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    Maybe not as much demand as you think. People can't give those things away.

    [​IMG]
     
  9. Dragon Tamer

    Dragon Tamer Member

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    Well in that case, I'll just throw it away.

    But I do have a few more things that I would like an estamate on
    First, 2 seperate CD-ROM drives, model CD-524EA, and IDE-40X (I think that's right)

    Second, an AIWA CX-NMT520U disk exchanger.

    And some RAM cards with model numbers I can't find. There are also some graphics cards lying around somewhere in a box that I need to find.
     
  10. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    All worth nothing - I've thrown loads away, as I'm sure everyone else has.
     
  11. mike11298

    mike11298 New Member

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    Sorry, but Nigel is right, I have loads of computer bits and pieces - many CD, DVD drives, Hard drives, cables, RAM, motherboards - its all worth close to nothing since computer parts at markets and whatever are soooo cheap.
     
  12. Dragon Tamer

    Dragon Tamer Member

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    But in my experience the principle rule with eBay is that there is a buyer for anything. I could sell my toilet on ebay if I wanted to. All I wanted to do is get a price estimation on some of the items I specified.
     
  13. Mikebits

    Mikebits Well-Known Member

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    Well then, just put them on Ebay with open bid.
     
  14. Dragon Tamer

    Dragon Tamer Member

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    I wish someone had told me that earlier! Oh well, no use crying over spilled milk. :)
     
  15. Cabwood

    Cabwood New Member

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    From that kind of stuff, you can get little magnets from the voice coil focusing mechanisms of CD and DVD drives, and their laser diodes, big magnets from HDD seek voice coils, lovely 6 and 8mm bars and from printer carriages, with their bushes, lots of steppers, infinite amounts of copper wire from coils, opto-isolators, opto-interrupters, mechanical limit switches, bearings, LEDs with PCB mounts and so on. From PSUs you can get nice ferrite cores for signal and power (and art projects), sometimes FETs, definitely some beefy diodes and heat sinks. Fans are quiet DC motors with wings that can be cut off. It's a paradise for tinkering.

    Or you can get $10 on ebay.
     
  16. Torben

    Torben Well-Known Member

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    You can scavenge some decent bits (magnets, motors, etc) as already noted.

    Make a couple of little robots. :)


    Torben
     
  17. amando96

    amando96 Guest

    17 Channel Logic Analyzer - CodeProject
    you'd also need a computer, a crap 233mhz bad boy with windows 98 should do it :D
     
  18. Vizier87

    Vizier87 Active Member

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    how about recycling? CRT coils are worth a few dollars, and so on. Might be worthwhile to visit your local scrapyard! :)
     
  19. vlad777

    vlad777 Member

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    Damn. I would be happy if there was so much free electro garbage (that may even work) in my country.
    I buy things like metioned for about a euro.
     
  20. Vizier87

    Vizier87 Active Member

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    There are hard-drive "recycletronics" projects in this page. Very interesting too.
     
    Last edited: Jul 6, 2010
  21. sania92

    sania92 New Member

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    I totally agree with Diver300
     

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