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.