LC low-pass and high-pass filter calculator
Online LC low-pass and high-pass filter calculator using Butterworth or Chebyshev prototypes: component values, the nearest E12 and a table of stopband attenuation.
LC bandpass filter calculator
Online LC bandpass filter calculator: transforming a low-pass prototype into series and parallel tuned circuits, with a warning when the bandwidth gets too narrow.
Crystal ladder filter calculator
Online crystal ladder filter calculator: coupling capacitors, termination impedance, external Q and how closely the crystals must be matched.
Quartz crystal parameters calculator
Online crystal parameter calculator: Cm, Lm, Q and the parallel resonance from measured fs and fp or by the G3UUR method, plus the pulling range.
Diplexer calculator
Online constant-impedance diplexer calculator for a mixer: first- and third-order low-pass and high-pass branch values, with an explanation of why the unwanted branch must be terminated.
Notch filter calculator
Online notch filter calculator: notch depth as a function of coil Q, the width of the notch at various levels, and both the series and parallel arrangements.