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  • Inductance question

    Hey folks, before I rewind this pickup. I have inductance readings of 6.97H @ 1kHz, 6.23H @ 100Hz, and 29.65H @ 120Hz.

    obvously something is wrong. Just curious how others would interpret those readings.
    ‘thanks!

  • #2
    PU impedance typically varies with measuring frequency.
    But the huge jump between 100Hz and 120Hz doesn't make sense.

    What type of PU?
    What's your meter?
    Last edited by Helmholtz; 04-25-2023, 07:37 PM.
    - Own Opinions Only -

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    • #3
      This is a P90 with magnets, keeper, and screws attached. Full disclosure: there are two different gauge wires I'm using 42 and 44 (an experiment). DCR reads good at 8.6k ohms.

      the meter is a UNI-T UT611

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      • #4
        6H to 7H for a P-90 looks normal. 30H is impossible. Did you measure disconnected from circuit?
        - Own Opinions Only -

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        • #5
          Originally posted by Helmholtz View Post
          6H to 7H for a P-90 looks normal. 30H is impossible. Did you measure disconnected from circuit?
          yes measured just on its own.

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          • #6
            Check your meter: Measure a bare PU coil with no metal parts attached or close. Should give roughly the same inductance reading at all 3 frequencies.
            - Own Opinions Only -

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            • #7
              Originally posted by StarryNight View Post
              Hey folks, before I rewind this pickup. I have inductance readings of 6.97H @ 1kHz, 6.23H @ 100Hz, and 29.65H @ 120Hz.
              It looks like the test instrument's ability to handle low-Q inductors has been exceeded. Don't know why 100 Hz worked while 120 Hz failed.

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              • #8
                Originally posted by Joe Gwinn View Post

                It looks like the test instrument's ability to handle low-Q inductors has been exceeded. Don't know why 100 Hz worked while 120 Hz failed.
                Isn't because 120Hz is an harmonic of the 60Hz hum due to the mains?

                FWIW: maybe nothing but that's what came to my mind...

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                • #9
                  Originally posted by freefrog View Post

                  Isn't because 120Hz is an harmonic of the 60Hz hum due to the mains?

                  FWIW: maybe nothing but that's what came to my mind...
                  No idea. Lower test frequency (100 Hz) is more likely to confuse the test instrument than 120 Hz, at least in theory.

                  Which test instrument are you using, by make and model?

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