Matching Low Pass Filter
This filter was designed from the program that is available on disc with Wes Hayward's book "Introduction to RF design". It is intended to provide good lowpass filtering for a 136kHz transmitter whilst also transforming the impedance from 4 ohms to 50 ohms. It avoids the use of a transformer, and the output capacitor can be made variable (a few switched fixed capacitors) to fine trim the impedance match.