Band Pass Filter

Three-Resonator 21 MHz BPF

BPF Design Notes

W3NQN Five-Resonator 21 MHz BPF, L1 L3 as Transformers

Transformer leakage inductance adds two series LC resonators to ground. W3NQN design reference, Figure 1 and Table 2B W3NQN band pass reference Figure 3 Transformer k tuned to match 28MHz response.

Five-Resonator 21 MHz BPF, L1 L3 with added Series LC Resonators

T80-6 8T #20 (Mem1) and T106-6 5T #20 (S11) Q Curves

VNWA Q measurement description