Abstract: A high frequency clock generator has a plurality of quartz crystals capable of providing various output frequencies coupled to multiple oscillator circuits. The output line from each oscillator circuit is coupled to one or more multiplexers so that the user can select one or more output frequencies at the same time. The multiple clock oscillator circuits and the multiplexer(s) are fabricated as an integrated circuit to minimize the degrading effects of weather and dust, to provide a fixed capacitive value and inverter bandwidth product, and to improve clock generator stability.