50MHz Elliptical Low Pass Filter


L1 = 165 nH (3mm silvered Cu wire)
L2 = 195 nH (3mm silvered Cu wire)
C1 = 60pF (1000V NP0)
C2 = 15pF (8pF Johnson trimmer par. 10pF ceramic 500V)
C3 = 100pF (4 x 100pF/1000V NP0,in series/parallel)
C4 = 5pF (piece of copper foil on a lead "flapper")
C5 = 47pF (1000V NP0)
Simulation made with RFsim99, blue trace is RL = 27dB at 50MHz; 2nd Harmonic -70dB; 3rd Harmonic -80dB; insertion loss < 0.15dB 
Real-life measurement is almost identical to simulation.

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Last modified 18.10.2006, Peter Frenning