Grabber on USB finally

Having had enough complaints about my grabber grabbing DSB, I finally decided to include the crucial crystal. Oh, btw, people complaining were of the kind who never actually run or built a grabber by themselves.

However, the suburban subharmonic direct conversion receiver is now equipped with a 10.140MHz crystal, used as a band-pass. Schematics are to be found on my webpage....

I wonder if the crystal makes a big difference, some (theoretical) improvement is expected anyway.