Tubes: What Numbers Shoud I get on hickock 539C

Discussion in 'Effects, Pedals, Strings & Things' started by wopr, Aug 21, 2008.

  1. wopr

    wopr Member

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    I have a chance to pick up some NOS 12ax7's, 6v6's, EL84's & 6L6's that are pulls. The guy I am buying them from has a hickock 539C tester. What numbers should I see for these tubes to be considered "new". And what are some bottom line numbers that I should pass on?


    Thanks,


    steve
     
  2. wopr

    wopr Member

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    I know, bumping my own, but . . . . last time. Anyone?
     
  3. 59Vampire

    59Vampire Silver Supporting Member

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    look up tone-lizard.com look at the pictures and see if you can get a shot of the meter. or do the same on ebay. either way the 539 is a great instrument
     
  4. amp_surgeon

    amp_surgeon Member

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    I don't mean to offend, but you're going to let the guy who's selling you the tubes also provide the tester you're going to test them with? Isn't this kind of like asking the car salesman to test drive the car for you? I mean, for brand new JJ's I wouldn't mind, but I assume you're paying premium prices for those NOS tubes. At the very least, I'd want to bring a bogey tube with me just so I could verify his tester was accurate.

    Ok, well, if you're going to trust that his tester is in good working order and calibration, then use the Gm numbers on the roll chart for each tube. Some 539C's don't have a roll chart, in which case you'll need the test data book for the 539C. I presume your seller will have this, as well.

    Bear in mind that the test data on the 539C roll chart is the MINIMUM value you should read, and not the AVERAGE, as is typical of other Hickok testers. This is because technicians asked Hickok for a pass/fail threshold, since the 539C didn't have a pass/fail test or meter scale.

    You should also keep in mind that the 539C does NOT test under actual load conditions. The plate voltage is generally a lot lower than what the tubes will see in an actual amplifier. Use the readings only as a guideline to whether a tube is operating more or less normally.
     
  5. wopr

    wopr Member

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    Thanks for the help. They're not cheap, but I'm not paying "top dollar" either, so I can afford some that are just ok. I hear you on trusting his tester, but I don't have my own tube tester, and can't walk away with his tubes to test them. So, its a gamble. Thanks for the food for thought, and keep the info coming.


    steve
     

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