Crystal Radio--SMD vs Air Core Coil Coupling (Basic)(4K)

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  • เผยแพร่เมื่อ 25 ธ.ค. 2024

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  • @franzliszt3195
    @franzliszt3195 17 วันที่ผ่านมา +1

    Super nice you matched the color on the scope with the color of the wire.

    • @tsbrownie
      @tsbrownie  16 วันที่ผ่านมา +2

      Yes, I bought the scope to match the coil!

  • @Ross-z1n
    @Ross-z1n 17 วันที่ผ่านมา +1

    The higher secondary voltage may be due to "transformer action" if the winding count is higher there, than in the primary (drive) winding.

    • @tsbrownie
      @tsbrownie  16 วันที่ผ่านมา +1

      @@Ross-z1n Very likely. Wish I had a current probe. They can be expensive.

    • @sebastian19745
      @sebastian19745 16 วันที่ผ่านมา +1

      No, most likely is because of the natural resonance of the secondary coil. There is a parasithic capacitance between the turns of any coil, and it happens that the resonant frequency of the secondary is around 1.3MHz. You see that is a narrow band where the secondary coil output is higher than the primary input. Maybe he can try to trace a Bode plot?

    • @tsbrownie
      @tsbrownie  15 วันที่ผ่านมา +2

      @@sebastian19745 That's a good point. I forgot about that. Thanks.

    • @Ross-z1n
      @Ross-z1n 15 วันที่ผ่านมา +1

      @@sebastian19745 Agreed. The phase change would also seem to indicate a resonance peak (as does the oscilloscope trace).
      I should have watched more closely.

    • @sebastian19745
      @sebastian19745 14 วันที่ผ่านมา

      @@Ross-z1n That is why I would like to see a transfer curve in amplitude and phase. The said Bode plot.

  • @franzliszt3195
    @franzliszt3195 17 วันที่ผ่านมา +1

    The phase change of the output is as expected.

    • @tsbrownie
      @tsbrownie  16 วันที่ผ่านมา +1

      @@franzliszt3195 It does not happen with the SMD inductors.

    • @franzliszt3195
      @franzliszt3195 16 วันที่ผ่านมา +1

      @@tsbrownie It has to, but could be small. Or phase change could be very flat over the frequencies of the AM band.