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Observations on a UPS - follow up to a previous post

Discussion in 'Electronic Repair' started by Doc, Aug 13, 2007.

  1. Arfa Daily

    Arfa Daily Guest

    Yeah,OK. I give in. You are right. I couldn't be more wrong if I tried. 35
    years down the pan. Just as an experiment, I wiped goose grease all over my
    LCD monitor and guess what? YOU ARE RIGHT !!!! ( that's for excited
    emphasis, I'm not shouting at you ). My picture is now so blurred that it
    looks just like the real world when I don't have my specs on. Accuracy or
    what ?!!! Have you thought of marketing this idea ? You could put it in tubs
    and sell it on the net as "Kony's patent image enhancing compound (blended
    with REAL snake oil )"

    My next plan is to see if I can drop a couple of bits on the input to the
    video card's DAC. That should increase the 'granularity' no end. This is
    another idea that could be put forward to monitor manufacturers to help them
    in their goal of making the reproduced image anything but lifelike, and
    better yet - *less* aesthetically pleasing !!

    Boy, you're a lad ! All these wickedly good ideas ! If you don't market them
    yourself, *I'm* gonna, and get really rich. Then you'll be sorry ! ;-)

  2. kony

    kony Guest

    The problem with goose grease is the high number of geese it
    would take to treat all monitors. :)

    Ok, I never did think capitalizing as shouting worked very
    well anyway, since the person has to read the text either
    way for it to matter.
    I'm not the one who wants to end up with less than the
    computer was designed to output. Yes the grease idea is
    crazy and has no merit but it is the type of degradation
    (albeit to a greater extent) causing your more lifelike
    image. CRT manufacturers didn't aim for that, it was just
    the result of the coating and thick glass. If LCD
    manufacturers wanted this, they could put a thick diffuser
    sheet on the front.

  3. So you answered the wrong post.
  4. Although my newsreader displays *word* in bold and /word/ in italics
    (if I let it).

    Hmmm - I've never tried both, like this:
    /*word*/ (looks like a comment to me!)

    I'll look at them when the message up shows in the NG...
  5. Both are in bold + italic here.

    Well, to be 100% accurate, the first is in italic + bold :)

    BTW, the reason I had to wait until I could read it in the NG is that
    this reader (MesNews) displays bold, italic, and smileys as straight
    text in the composition window.
  6. Arfa Daily

    Arfa Daily Guest

    Yeah, OK! Just messin' with ya! Really, I don't have a problem with my LCD
    monitors. Both of them look just fine. But subjectively, a CRT picture just
    has something that makes it a little more 'human' to my perception. I would
    guess that it's the same as CD versus vinyl, where the vinyl has a 'warmer'
    sound (oddly, Steve Wright was discussing exactly this on his BBC radio
    programme today, and it was his opinion that CD sounded 'cold' compared to
    vinyl). Another example might be programme material shot on video tape,
    versus that shot on film stock. Outdoor scenes in particular always have a
    flat, cold, unrealistic look to them, when shot on video, but I'm sure that
    you would probably be able to apply your 'more accurate not lifelike'
    analysis to these examples as well. Anyway, all of this is causing me to
    lose the will to live now, and I'm done with it. I think we better just
    settle on agreeing to differ ... Later

  7. Arfa Daily

    Arfa Daily Guest

    So I guess that's why the common convention is to use slashes and asterisks.
    I never knew that some newsreaders actually interpreted these as such. Learn
    something new every day ! So that does leave capitalization free for
    'shouting' ... d;~}

  8. Guest

    That's hard to believe. A problem common with CRTs is trying to achieve
    convergence of all three colors everywhere on the screen. Lack of
    convergence leads to loss of sharpness. Convergence is not an issue on
    flat panels.
  9. Arfa Daily

    Arfa Daily Guest

    I don't really think that cvonvergence has been much of an issue since
    slotmasks became the norm many years ago, as these are inherently self
    converging. Whilst very cheap-end CRT monitors and TV sets might still have
    some slight convergence issues at the screen extremities, I can't honestly
    say that I have seen anything in this respect worth commenting on, for some
    years now. Perhaps I'm just lucky, or just selectively seeing what I want
    ( or don't ! ) want to ... d;~}

  10. Guest

    How so?
    I have.
    There's also the issue of focus. I've seen CRTs go "soft" as they age.
    Focus is not an issue on flat panels.

    Then there's magnetic effects. Aside from degaussing, which modern CRTs
    are designed to do automatically, you have to worry about external fields,
    such as from nearby loudspeakers. I had a modern CRT image start to
    "shimmy" when an outdoor security light came on every evening. Flat
    panels are immune to external magnetic fields and don't need degaussing.
  11. Arfa Daily

    Arfa Daily Guest

    It is largely a function of the precision wound deflection yoke that is
    carefully matched to the CRT at the factory. This yoke requires only basic
    static convergence to be adjusted, and this is accomplished usually with a
    combination of 4 and 6 pole annular magnets at the rear of the yoke. See
    second para from bottom


    It is fairly rare for CRTs to age this way these days. Often, something else
    in the circuitry fails, to render the monitor not worth repairing, before
    the CRT is showing serious signs of aging, although I do accept that this is
    a potential age-related failure mode of a CRT display. Whilst I agree that
    focus per se is not an issue that can be directly related to LCD display
    technology, many cheap end displays never-the-less do not look as sharp as a
    *good* CRT display, and also suffer from serious motion blur, both as a
    result of switching lag in the LCD cells, and display drive circuitry. There
    are other issues with LCD monitors, which some consider to be a bigger
    problem than the minor defects with CRT display technology. These include
    poor contrast ratio, poor eveness of the back illumination, fairly rapid
    wearing of the CCFLs providing that illumination, very poor results with a
    drive source resolution of anything other than the panel's native figure,
    and motion blur as already discussed.

    Focus of modern CRTs is well taken care of. Very well performing dynamic
    focus circuits have been in common usage for some years now, and the CRTs
    electron lenses are carefully designed to maximise the beneficial effects of
    this. Again, some cheap end monitors / TV sets are not terribly good in this
    respect, but that is more of a cost than technology issue. On a decent
    quality CRT display, you would be fairly hard pressed to find focus errors
    worth complaining about.

    Magnetic effects should not be an issue with modern CRTs, unless a powerful
    field is brought close to the face of the CRT. The construction of the
    device includes a magnetic shield, and before they did, they were surrounded
    by a mu-metal shield, which blocked all but the strongest interfering
    fields. It is not the CRT which degauses itself automatically. Rather, it is
    a piece of circuitry which at switch on, applies an initially large,
    progressively decaying, AC current to the degausing coils surrounding the
    CRT. In the case of a TV set, that's it, but with a computer monitor, as
    well as this automatic degausing at switch on, a manual switch or menu
    option is often provided as well, to allow for a 'hot' demagnetisation. I've
    never really understood why manufacturers thought this necessary. Maybe
    because monitors are mounted on a tilt and swivel base, which could result
    in purity errors due to the realignment of the earth's magnetic field if you
    do spin the monitor round, but it would have gone back right anyway, when
    you turned it back. Still, it looks pretty, if you're bored with what you're
    doing ...

    As far as your monitor shimmering when the outside light came on, I would
    suggest that this was nothing to do with magnetic fields or CRT technology.
    Far more likely to be mains-borne mutual interference between the monitor's
    switch mode power supply, and something like triac switching in the outside
    light. Did you ever pin down what you thought was actually causing the
    problem ?

  12. Arny Krueger

    Arny Krueger Guest

    Agreed. I believe that if money and maintenance are not issues, you can
    still get the best visual quality with CRTs.
  13. :)

    You could always put in metacommands, like below:

    I noticed in configuring something on the Mac a couple of days ago (I
    forget what, sorry) that stars can bracket bold words and underscores
    can bracket italics in that app. I think this newsreader displays
    _word_ as an underscored word, but I won't know until I read it as an
    incoming article, as before.

    I knew about stars for emphasis, but I didn't know about displaying it
    as bold type until I started using MesNews a couple of years ago.
  14. Arfa Daily

    Arfa Daily Guest

    Just goes to show how many years you can use something for, and still not
    know all about it. The underlining thing is yet another one to add to my
    knowledgebase. So I wonder if you can both bracket and slash either side to
    ensure that it will get read as italics in either variety of reader. And
    then again, can you add stars as well for bold and italics ?


  15. Arfa Daily

    Arfa Daily Guest

    Senior moment. That should of course, have read "underscore and slash". I
    hate getting old ...

  16. Just to make you feel younger:

    */_test phrase_/*

    For some reason, I felt I had to do LIFO on the markers :)
  17. Arfa Daily

    Arfa Daily Guest

    LOL ! Thanks. Feeling better now ...

  18. Dan

    Dan Guest

    enough to get me through short hit outages with both machines running.
    If i may ask a related question: ups comes with small batteries so as
    to make it portable. Once I've put it in a permanent location, can I
    connect a bigger battery by using cables (say replacing the 12 Ah with
    30 Ah battery?) or the charger will be exhausted bringing the bigger
    battery up to capacity?
  19. Ken

    Ken Guest

    The UPS can get too hot.
  20. Guest

    Meanwhile, see lots of current CRT televisions. I witnessed one
    tonight with horrible convergence, and it's relatively new.
    Sort of like how CRTs are allegedly inherently self converging, when
    simple inspection shows that they are not?
    Comparing a cheap something to a good something is like comparing apples to
    oranges. Hardly a valid comparison.
    LCD response times are getting shorter and shorter.
    If you find the blur unacceptable, then use the right tool for the job.
    I use a television to watch motion pictures, and I use a computer display
    for computer tasks.
    "Poor" is subjective. One can be lower than another, but can the user
    tell the difference? To use an analogy, consider a loudspeaker with
    frequency response up to 25 kHz; compared to one with response up to
    30 kHz, one might call it "poor", but how many listeners will be able
    to tell the difference? I've seen LCDs side-by-sde with plasmas that
    claim to have contrast ratios an order of magnitude higher, but you
    can't really tell from the content being shown.
    Sort of like a CRT after an image has been burned in. A great example are
    the airport monitors showing flight arrival and departure information.
    Manufacturers are switching to LEDs for illumination.
    CRTs have the same problem in one dimension when using Trinitron-style
    (aperture grille) tubes with vertical color stripes, and in both dimensions
    when using tubes with dots (shadow mask). With NTSC, broadcast (about 330
    lines) always looked sharper than VHS-SP (about 240 lines). Super VHS
    could supposedly do about 400 lines, and ED Beta about 500 lines, but
    what if your CRT didn't have 500 phosphor triples in that direction? You'd
    never see the benefit of the technology.
    And my response as already presented.
    CRTs have been around for a long time. Manufacturers have had lots of
    time to tweak the technology, and mass production has brought prices
    down. LCDs are newer technology, still undergoing rapid development
    (panels are getting bigger, resolutions are getting higher, stuck pixels
    are getting fewer, manufacturing yields are improving, response times
    are faster, viewing angles are getting wider, backlights are getting
    more reliable. Reminds me of the debut of the Compact Disc. The earliest
    players had a tough time measuring up to the state-of-the-art in analog.
    Can you see through a mu-metal shield?
    The circuitry doesn't need degaussing. The CRT needs degaussing, hence
    saying the CRT is designed to be automatically degaussed is the more
    appropriate description.
    With LCDs, you don't need to worry about the Earth's magnetic field.
    All I can say is that other computer monitors on the same power circuit
    didn't shimmy when the outdoor light came on, but the large Mitsubishi
    Diamondtron did. The strength of the field was measured, and the measurer
    claimed that it was less than that produced by an electric pencil sharpener,
    said that the lights were operating within specs, and didn't do a thing to
    help eliminate the problem with the computer monitor. "Not their problem."
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