The two oscillator circuits under are suitable for utilizing crystal oscillators in series or parallel manner: Large-repetition-fee and substantial-electrical power picosecond regenerative amplifier based on only one bulk Nd:GdVO4 crystal A timing reference incorporating an individual-crystal-silicon micromechanical resonator with a high quality variable of bigger than a million plus a https://www.hxcrystals.com/seokeywords/bulk-crystal-oscillator.html