An old formula that was shared with me some time back that can be used to calculate the needed inductance of the antenna coil (tank circuit) in micro-henries based on the variable capacitor range in pF (picofarads). for a given operating frequency range in kHz.

Another formula below:
L uH = (25330 / (C pF * F MHz * F MHz)

L = micro-henries
C pF = variable capacitor in picofarads
F MHz = frequency in MHz

LC Calculations Made Simple
   • LC Calculations Made Simple  

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