Tube bias chart?

Discussion in 'Shock Brother's DIY Amps' started by nasdak, Oct 22, 2019.

  1. nasdak

    nasdak Tele-Meister

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    Hello!
    I've been doing a lot of tube testing lattely with my utracer.
    It's a nice device, there's a quick test mode where you set the plate and screen voltage and it gives you Ia, Ig and Gm. Voltage goes up to 400v.

    What i miss is a convenient chart where i can find what values are expected for a "good" tube and that i could print and put on my desk wall.
    For example EL34@ 400v, acceptable values for ia, ig, gm
    I know i can find thoose data in the datasheets but when testing different tube etc... It's not very handy.
    So i have to make this chart (could be a excel sheet)
    Or maybe, someone did it already ?

    Envoyé de mon Redmi 4X en utilisant Tapatalk
     
  2. Urshurak776

    Urshurak776 Tele-Holic

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    Member @Freeman Keller made a fantastic excel spreadsheet. He will probably send it to you if you PM him. He did it for me, but up to him if he wants it shared.
     
  3. bblumentritt

    bblumentritt Tele-Afflicted Platinum Supporter

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  4. Freeman Keller

    Freeman Keller Tele-Afflicted

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    I think I have been mistaken for my evil twin. I made a fantastic excel spreadsheet to help me (and other) analyze and set up instruments but it has nothing to do with tube bias....
     
  5. nasdak

    nasdak Tele-Meister

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    Thx !

    not what i'm loiking for.. don't want to bias my tubes for max dissipation but to test them !


    thanks anyway !
     
  6. D'tar

    D'tar Friend of Leo's

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    [​IMG]

    ******This is not mine nor have I checked it for accuracy!*******
    And is surely not exactly what you are after;-)
     
    Last edited: Oct 24, 2019
    King Fan likes this.
  7. Les Gear

    Les Gear TDPRI Member

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    Weber has a comprehensive page, including a quick-and-dirty calculator bias calculator and a q&d output power calculator, a detailed combination calculator and five rough-and-ready charts for different types of power tubes.

    I'm somewhat color-blind. I can see that there is a middle "normal" column on the charts but can't read the green or yellow or whatever unless I highlight the chart. It's always interesting to be compelled to confront my physical defects!
     
  8. Urshurak776

    Urshurak776 Tele-Holic

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    Sorry everyone! I must have gotten my tubes crossed......
     
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