VCXO-S522-78.336MHZ VCXO-S524-LF VCXO-S524LF(18MHz) VCXOS532-LF VCXO-S546-LF VCXO-S579-LF155.52MHZ VCXO-S579-LF-155.52MHZ VCXO-S618-LF-122.88MHz VCXO-S622-LF-125MHz VCXO-V53-A312-30.72MHz