I played with crystal filters a while back, and found that the low profile? HC-49s crystals aren't suited for wider bandwidths (SSB), but are OK for CW filters.? I was experimenting at 4.9 MHz, at 9 MHz it will be different.? Just something to be aware of.? The full height HC-49 crystals I had checked out OK for SSB filters.
Jim Allyn - N7JA