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Power transformer readings

Discussion in 'Shock Brother's DIY Amps' started by Jewellworks, Sep 20, 2020.

  1. Jewellworks

    Jewellworks Tele-Meister

    Mar 2, 2020
    ive got this power transformer that came out of an old Ampro Projector that was running 3, 6V6's, 5Z4, 6SJ7, 6J5 and something else... i planned on using it for my "Vintage Build" and i just got around to finding out whether its dead or not. turns out its not. so yay. but i wanted to post the readings i was getting from it, un-installed, and just sitting on my workbench. -to see if anything jumps out as abnormal, or is it good to go?

    primary: 5.9ohms

    HT: 217.4
    HT-a to C/T: 103
    HT-b to C/T: 114.6

    6.3v Filament: .03
    F-a to C/T: .02
    F-b to C/T: .04

    5v Heater: .03

    VOLTAGES: using a variac, i set the input to the primary at 120VAC

    2ndary: HT: 862 VAC (!!)
    HT-a to C/T: 432
    HT-b to C/T: 429

    6.3v Filament: 7.53
    F-a to C/T: 3.77
    F-b to C/T: 3.73

    5v Heater: 5.77

    im concerned about what looks like an enormous voltage on the HT 2ndary, and it being un-even on either side of the C/T by just a few volts. i can always knock the voltage back with some big resistors, but im sure the un-even-ness will this balance out with the filter caps.

    the 6.3v filament seems high, but theres no load. can i add a Humdinger to balance the load? with a C/T filament? ive seen posts with people talking about "elevated filaments" but i dont really know how that works, or for what purpose.

    im thinking its good overall, but probably way more than what i need for my Vintage build. but its what i have on hand, so there you go.

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