On the origin of OXCO (for oven controlled crystal oscillator):

The base abbreviation is "Xtal" (for crystal) and predates modern electronics by quite a bit (was already used before 1900 in geology etc). The author linking this to Xmas (indirectly, "Christ") via the the greek Chi (Χ) is very likely correct.

In electronics this weird abbreviation (X for crystal) is further helped by the fact that "C" is completely taken by "capacitor" (an even more important passive component).

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ACCount37 3 hours ago | parent [-]

Amusingly, "crystal oscillator" can be both "X" and "Y" in schematics.

"X" because "xtal", and "Y" because of the distinct shape of a tuning fork.

	▲	SAI_Peregrinus 2 hours ago \| parent [-]
		Even more amusingly, only low-frequency crystals (very often 32.768kHz) are tuning-fork cut, high-frequency resonators use other shapes. Pedantically most of them aren't crystal oscillators, merely crystal resonators. Oscillators begin oscillating on their own when a DC voltage is applied, they usually are 3-pin or 4-pin devices with power input & oscillating outputs. 2-pin crystal resonators merely act as high-Q filters in an oscillator circuit, they still need other components to drive the oscillation.