The two oscillator circuits down below are appropriate for using crystal oscillators in sequence or parallel manner: Large-repetition-level and large-ability picosecond regenerative amplifier depending on one bulk Nd:GdVO4 crystal A timing reference incorporating a single-crystal-silicon micromechanical resonator with a top quality component of larger than one million and also a https://www.hxcrystals.com/seokeywords/bulk-crystal-oscillator.html