Structural integrity of CRTs?

Discussion in 'General Electronics Chat' started by Hypatia's Protege, Aug 12, 2015.

  1. Hypatia's Protege

    Thread Starter Distinguished Member

    Mar 1, 2015
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    Kind friends:

    I seem to have encountered an insurmountable obstacle as regards my attempts to retrofit a vintage TV receiver with a 'modern' CRT...

    Despite my best efforts I find that removal of the mounting band from CRTs having a diagonal face dimension greater than Ca. 28" (~71 cm) invariably results in instant breakage of the tube!:( --- Please understand that I have exercised every precaution by way of avoidance of 'nicking' or otherwise damaging or stressing the glass! -- In point of fact my last attempt consisted of merely 'undoing' the cinch with surgical picks sans contact or increased stress on the envelope -- Nonetheless the tube suffered instant implosion upon release of the band's tension!:mad::confused: -- Ludicrous though this may sound - I'm compelled to wonder if the band serves as some manner of structural 'member'?!?!:confused:

    Having gone through four pristine NOS tubes in this fashion I'm hesitant to jeopardize my two remaining 'prospects' with any further (of my) 'bright' ideas:rolleyes: --- Any thoughts, advice or 'magic spells' will be greatly appreciated!!!:):):)

    Best regards
    HP
     
    Last edited: Aug 12, 2015
  2. #12

    Expert

    Nov 30, 2010
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    Throw us a photo (or three)!
    I was doing this job before I could legally buy a beer.
    What HAVE they changed? :eek:
     
  3. MaxHeadRoom

    Expert

    Jul 18, 2013
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    I did that job for a few years when the CRT was in vogue but never had a problem with mounting frame, it sounds almost as if something you are mounting to is warped maybe and when reefing the mounting bolts the incident occurs?
    If this is on the same TV.
    Thats an expensive lesson!:eek:
    Max.
     
  4. Hypatia's Protege

    Thread Starter Distinguished Member

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    Thanks for the replies!:)

    Owing to their fragile nature and the fact that I have only two left:(:eek: I prefer to leave them in their cartons prior to use

    FWIW I found this image of similar (albeit much smaller) tubes --- notice the metal band (carrying the mounting 'ears') near the faceplate...

    http://photos.prnewswire.com/prnvar/20140310/SF79743

    I dunno seems the mounting band has powers unknown!:confused:

    @MaxHeadRoom
    I apologize that I failed to make a clear statement of my problem:oops:

    Fitting of the 'new' tube to the receiver requires that I first remove its factory equipped steel band (said band being cinched 'round the 'bell' immediately back of the faceplate) unfortunately removal of said band, no mater how gently done, results in implosion of the tube at the instant the tension is released:(:mad: While I can't imagine a design employing such an 'accessory' as an ancillary structural element - such seems to be the case?:confused: --- Unless, that is, I'm missing something (wouldn't be the first time! :rolleyes:)

    Best regards
    HP
     
  5. Nykolas

    Member

    Aug 27, 2013
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    3 instantly imploded? And you are still alive? E
     
  6. Hypatia's Protege

    Thread Starter Distinguished Member

    Mar 1, 2015
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    Actually 4 :mad::(

    After an initial 'blood letting', I wised up on the 'PPE' front:eek::rolleyes:

    Best regards
    HP
     
    Last edited: Aug 12, 2015
  7. #12

    Expert

    Nov 30, 2010
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    You are not supposed to remove the band!
    You might cut the ears off, but you must not remove the band.
    Besides, how you gonna mount it without ears?:confused:

    Your stubbornness must be abandoned!
     
  8. Hypatia's Protege

    Thread Starter Distinguished Member

    Mar 1, 2015
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    Do you mean to say the band is indeed a structural component as opposed to a mere breakage mitigation feature!?!? --- First unibody automobiles now ''tubes with trusses" -- Just when I thought I'd seen everything!!!:eek:

    The mounting hardware in the old receiver is rather like a large hose clamp:)

    Let us not confuse obdurateness with desperation...:oops:

    Best regards
    HP
     
  9. #12

    Expert

    Nov 30, 2010
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    Dammit. Dictionary time again.:mad:

    OK. I'm back. I did not say anything about desperation.
    Your obdurateness must be abandoned.
     
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  10. Hypatia's Protege

    Thread Starter Distinguished Member

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    hose-clamp
    [​IMG]
    Noun
    (plural hose clamps)

    1. A device used to attach and seal a hose onto a fitting.

    TTFN
    HP;););););););););););););)
     
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  11. Hypatia's Protege

    Thread Starter Distinguished Member

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    My point was that I felt you were confusing my desperation (as regards my restoration project) with obdurateness:)

    Best regards
    HP
     
  12. #12

    Expert

    Nov 30, 2010
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    And...once again I am convinced you are female.
    I don't give a fig about your emotions, especially when compared to your safety.
    Men are like that. Get the job done safely, then, if you have time to get sloppy drunk, whine about your feelings (or what you imagine somebody might be thinking about your feelings). :rolleyes:
     
  13. Hypatia's Protege

    Thread Starter Distinguished Member

    Mar 1, 2015
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    What the hey! 'Even money' is better odds than you'll likely find at the track!;)

    TTFN
    HP

    PS: Your concern for my safety is genuinely appreciated!:)
     
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  14. alfacliff

    Well-Known Member

    Dec 13, 2013
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    I have been replacing crt's in tv and monitors for a lot of years, and I have never had to cut a band off. the band is for mounting, not for shipping puroses. find a way to mount the tube with the band intact.
     
  15. Hypatia's Protege

    Thread Starter Distinguished Member

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    Well I've learned my lesson! -- To the tune of a barrel full of shards that used to be $300 apiece virgin NOS CRTs:(:(:(:mad::mad::mad:

    Seems I'll have to...:(:confused: Trouble is, these 30" (diagonal) wide deflection angle tubes are challenging to mount in the old cabinets -- I'm 'toying' with the idea of fashioning a polycarbonate 'cradle and yoke' assembly -- either way the mounting 'ears' will have to come off... --- Nothing's ever easy!:mad::mad::mad:

    Thanks for your reply!:)

    Best regards
    HP
     
  16. crutschow

    Expert

    Mar 14, 2008
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    It would seem apparent that the band provides structural integrity to the tube.
    If you calculate the total atmospheric pressure on the face of the tube you will be amazed that any tube can survive without imploding.
    I assume that when they went to large, flat-surface tubes, it was impractical to built the glass strong enough to resist this pressure so they added a metal band to provide the needed strength.
    But that's just a guess.
     
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  17. #12

    Expert

    Nov 30, 2010
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    The, "nothing" in this case is your obdurateness. You have $1200 worth of, "I'm stubborn" and you still insist on removing the approved mounting method. If you worked for me, I would fire you.:mad:
     
  18. MaxHeadRoom

    Expert

    Jul 18, 2013
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    I wonder how you came to the conclusion that the band needed removing?
    The new ones should have given you an idea as they are drop in replacements usually?
    Max.
     
  19. #12

    Expert

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    He just wants to fit this in a place that's too small and refused to accept that the metal band is part of the structural integrity.
     
  20. Hypatia's Protege

    Thread Starter Distinguished Member

    Mar 1, 2015
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    @#12
    @MaxHeadRoom

    Gentlemen!:)

    Each of you seem to have missed the highlighted text in the following quotation from my OP:
    Be it ever so inelegant, even reckless, kludge I must!:cool:

    Best regards
    HP:)
     
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