Elsie Plot of QRP-Labs 7-pole 40-m LPF

This is the schematic of the 7-pole LPF used in the QRP Labs 40-meter LPF:

The plot from Elsie 2.77 for the above filter looks like this:

The actual SA response curve looks like this:

The curves are remarkably similar.  Knee around 8.8 MHz, about 36 dB down at 14.08 MHz.  Loss at 7.04 MHz is a bit worse on Elsie, but that is based on Q values of 40 for the coils and 200 for the caps — both are probably a bit better.

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