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    Tube Testers

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    Poll

    How many here have a tube tester of any nature?

    [ 7 ]
    28% [28%] 
    [ 8 ]
    32% [32%] 
    [ 5 ]
    20% [20%] 
    [ 5 ]
    20% [20%] 

    Total Votes: 25
    avatar
    Peter W.

    Posts : 758
    Join date : 2016-08-07
    Location : Melrose Park, PA

    Tube Testers

    Post by Peter W. on Thu Mar 01, 2018 11:42 am

    I am still planning to give a Dynaco Clinic - but between incipient hip-replacement surgery and starting a new job, the opportunities for same have been mortgaged into the late spring.

    I am noticing an increasing number of posts that seem to involve symptoms that could be tube-related, could be something else, or both. And the diagnosis and treatment of such symptoms become problematic as treating one symptom without addressing an underlying 'different' cause may mask a problem that will only come back in short order.

    So, on a Reasonable Notice Basis, I am willing to offer the use of my Hickok 539B Tube Tester, located in Melrose Park, PA (just outside the Philadelphia City Limits) for use to any and all comers. It has the capacity to match (with the use of outboard VOMs) and within the universe of general-purpose tube testers is one of the better ones. No cost, of course, nor do I have tubes to sell nor am I soliciting in any way.

    I would like to see other participants of this forum offer the same option if possible so that such capacities may be extended beyond my immediate area. Just determining whether the tubes are a factor can add a great deal of clarity in diagnosing issues with any amp.
    avatar
    jfine

    Posts : 164
    Join date : 2017-06-19

    Re: Tube Testers

    Post by jfine on Thu Mar 01, 2018 1:50 pm

    So far it seems like I need to try the tube in the actual circuit it will be used in, my basic tester always shows good, probably was a waste of money, not going to tell me if it will make the entire rack sensitive to touch. Not sure I believe in close matching either, heard they can get out of match in a few weeks or so anyway.
    avatar
    Peter W.

    Posts : 758
    Join date : 2016-08-07
    Location : Melrose Park, PA

    Re: Tube Testers

    Post by Peter W. on Thu Mar 01, 2018 2:03 pm

    jfine wrote:So far it seems like I need to try the tube in the actual circuit it will be used in,

    This is always the case. even with a "high-end" tester. However, a tube with an incipient short or one that is severely microphonic should be detectable by even a decent emissions tester (one that has settings for 'shorts' and 'gas'.

    my basic tester always shows good, probably was a waste of money, not going to tell me if it will make the entire rack sensitive to touch.  That is too bad, Seems like you have the opposite of the typical "drug-store" tester designed to sell tubes. If it is a name-brand, you might need some level of calibration.  

    Not sure I believe in close matching either, heard they can get out of match in a few weeks or so anyway.  True, and true. It is my direct experience that modern-production tubes are very prone to drift after a few hundred hours or even much less. I have a set of 1960s Siemens tubes with many thousands of hours on them that are within 5% today - whether by design or pure blind luck. Won't see that often now.

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