The filter was build in a tin box 160x100x50mm. All inductors are wound on a 20mm dia. Wire thickness is 2mm copper wire. Capacitors are ATC800 series these can be replaced by doorknob capacitors or any othe capacitor suitable for the power used..
The schematic looks as follows:
| Component | Value |
|---|---|
| L1 | 3 turns 20mm dia 30mm long |
| L2 | 4 turns 22mm dia 30mm long |
| L3 | 4 turns 25mm dia 30mm long |
| L4 | 1 turns 20mm dia 20mm long |
| L5 | 1 turns 20mm dia 10mm long |
| C1 | 68pF |
| C2 | 68pF |
| C3 | 39pF |
The suppression of the second harmonic is good. If more attention was payed to the shielding of the individual inductors -50dB would be possible. The input match is good with -25dB and was easy to obtain.
