BPF Design

Use "Band-Pass Filters for HF Transceivers" as a design guide Select material based on Q Measurements 0.5uH range, use -10 above 10MHz, else -6 2uH and above, use -6 21 and 28 MHz Shunt Poles, use self supported coils

28MHz 3-Pole Example

SimSmith Design

3-Pole Tuning Procedure
Short across Series Pole location(s) Connect Analyzer to Left BPF port Connect 50Ω load, or VNA Port 2, to Right BPF port Add Left Shunt Pole and tune inductor for SWR Dip Add Right Shunt Pole and tune inductor for SWR Dip Add Series Pole and tune inductor for Center Band-pass
5-Pole Tuning Procedure
Start with 3-Pole above Add second Series Pole and tune inductor for dip Add Middle Shunt Pole and tune inductor for Center Band-pass

28MHz 3-Pole Tuning Example

Tune Left Shunt Pole

VNWA Left Shunt Pole

Tune Right Shunt Pole

VNWA Two Shunt Poles

Tune Series Pole

Three-Pole VNWA Measurement

Tune 2nd Series Pole

With 2nd Series Pole VNWA Measurement

Tune 5-pole Middle Shunt Pole

5-Pole VNWA Measurement

7.15MHz 4-Pole Example

Use LC Filter Design Tool For pole capacitor values. Set SimSmith LC's to locked at center frequency Set SimSmith LC capacitor values to design tool values. Tuning Prodedure Pole Add order, using SimSmith LC# LC1, LC2, LC3, LC4

SimSmith Design