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    I'm looking for a "key" to reading tube datasheets

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    mrconclusion

    Posts : 15
    Join date : 2012-10-18

    I'm looking for a "key" to reading tube datasheets

    Post by mrconclusion on Fri Nov 23, 2012 8:47 pm

    Hi everyone!

    Does anyone know where to find a nice all-in-one list to decode all the scientific abbreviations used on tube datasheets? I don't need a glossary of terms; just a list of the plain English names for characteristics like Vba, Vbg2, dtot, Rk, etc.

    If anyone knows of a page I can print out to use as a cheat sheet until I learn this stuff - I'd be grateful!

    tubes4hifi
    Admin

    Posts : 1261
    Join date : 2008-11-30

    Re: I'm looking for a "key" to reading tube datasheets

    Post by tubes4hifi on Sat Nov 24, 2012 5:55 pm

    I don't know if this will help or will put you to sleep, more info on tubes than I can even comprehend, about 428 pages worth!!
    http://www.dscc.dla.mil/Downloads/MilSpec/Docs/MIL-STD-1311/std1311.pdf
    another interesting tube link:
    http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=14225

    baddog1946

    Posts : 304
    Join date : 2010-02-03
    Location : Costa Rica

    Re: I'm looking for a "key" to reading tube datasheets

    Post by baddog1946 on Sat Nov 24, 2012 8:21 pm

    HI:
    I think what you are looking for may be here.
    Cheers!
    Baddog


    TRIODES - TUBE OPERATING PARAMETERS
    Ib = Plate (P) current, in milliamps
    Ik = Cathode (K) current, in milliamps
    Ic1 = Grid (G) current, in milliamps
    Eb = Plate to cathode potential (P to K), Volts
    Ec1= Grid (G) to cathode potential (K), Volts
    Ek = Cathode (K) to ground potential, Volts
    Ef = Filament AC voltage (Volts AC rm

    PENTODES - TUBE OPERATING PARAMETERS
    Ib = Plate (P) current, in milliamps
    Ik = Cathode (K) current, in milliamps
    Ic1 = Control Grid (grid No. 1(G1)) current in milliamps
    Ic2 = Screen (grid No. 2(G2)) current, in milliamps
    Ic3 = Grid No. 3 (G3) current, in milliamps
    Eb = Plate to cathode potential (P to K), Volts
    Ec1 = Grid (grid No. 1) to cathode potential (G1 to K), Volts
    Ec2 = Screen (grid No. 2) (G2) to cathode, Volts
    Ec3 = Screen (grid No. 3) (G3) to cathode, Volts
    Ek = Cathode (K) to ground potential, Volts
    Ef = Filament AC voltage (rms)

    STANDARD CIRCUIT PARAMETERS
    Ebb = Plate supply voltage to ground (DC)
    Eb = Voltage at the plate (DC)
    Ec2 = Screen grid voltage (DC)
    Esig = Input Signal voltage (RMS)
    Eout = Output voltage to following grid (RMS)
    Ec1 = Grid 1 to cathode voltage (DC)
    Ec2 = Grid 2 to cathode voltage (DC)
    Ec = Grid set bias (grounded cathode) voltage (DC). In the charts this is reported as the
    grid to cathode voltage.
    Ib = Plate current, (Ma-DC)
    Ic1 = Grid 1 current (Ma-DC)
    Ic2 = Grid 2 current (Ma-DC)
    Rc2 = Screen dropping resistor (Meg-ohms)
    Rcf = Grid resistor of following tube (Meg-ohms)
    Rb = Plate load resistor (Meg-ohms)
    Rk = Cathode resistor (Kilo-ohms)
    Gain = The ratio of output signal voltage to input signal voltage.
    %Dist = A value reported, but not defined as to how it was determined.

    THE BASIC RELATIONSHIPS
    TRIODES
    Data on the characteristic behavior of triode vacuum tubes is in the form of a tetrad.
    Plate-to-cathode voltage Eb or eb
    Grid-to-cathode voltage Ec1 or Ec or ec
    Plate current, Ib or ib
    Grid current, Ic, Ic1 or ic
    Grid current is rarely shown, except for those tubes where the application is in rf or if
    frequency regions or in pulse applications.
    The standard graphical plots show the relationship between a tube plate current and a
    cathode to plate voltage for different grid to cathode voltages.
    If we define grid current as positive when electrons are flowing out of the tube grid then
    1) Ik = Ic + Ib (all in the same units)
    Also the graphs show Ib on the left vertical axis and Eb on the horizontal axis with
    reference to the cathode at ground potential. This is the only way to properly view the
    characteristic curve plots.

    PENTODES
    Data on the characteristic behavior of vacuum tubes is in the form of a tetrad or pentrad.
    Plate-to-cathode voltage (Eb)
    Grid (G1)-to-cathode voltage (Ec1)
    Grid (G2)-to-cathode voltage (Ec2)
    μ is called the “amplification factor” or mu
    rp is called the “plate resistance”
    gm is called the “transconductance”

    mrconclusion

    Posts : 15
    Join date : 2012-10-18

    Re: I'm looking for a "key" to reading tube datasheets

    Post by mrconclusion on Sat Nov 24, 2012 9:12 pm

    Thanks to both of you - Exactly what I was looking for and even more!

    tubes4hifi
    Admin

    Posts : 1261
    Join date : 2008-11-30

    Re: I'm looking for a "key" to reading tube datasheets

    Post by tubes4hifi on Sat Nov 24, 2012 9:43 pm

    BadDog - good, that's what I was looking for too! good stuff . . .

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