A number of quartz oscillator suppliers resell MEMS oscillators. Its transmitter, now directly controlled by a quartz oscillator, was moved to College Park, Maryland. The radiation also caused phase shifts in Galileo's ultra-stable quartz oscillator. The radiation also caused phase shifts in "Galileo"<nowiki>'</nowiki>s ultra-stable quartz oscillator. Typically a quartz oscillator is used in the receiver to do the timing. The quartz oscillator or resonator was first developed by Walter Guyton Cady in 1921. Initially a quartz oscillator in a temperature controlled oven was used as the master clock.