Advanced Qualification · A-003 Measurements · A-003-004-010
Out of the following oscillators, one is NOT, by itself, considered a high-stability reference:
- A temperature compensated crystal oscillator (TCXO)
- B oven-controlled crystal oscillator (OCXO)
- C GPS disciplined oscillator (GPSDO)
- D voltage-controlled crystal oscillator (VCXO)
Correct answer: D — voltage-controlled crystal oscillator (VCXO). From the official ISED question bank, verified word for word.
Why
A voltage-controlled crystal oscillator (VCXO) is not a high-stability reference because its frequency changes when you adjust the voltage, making it unstable for precise timing. The full explanation — and one for every question — is in Pro.
Practise this section
Measurements: meters, oscilloscopes, counters, signal generators, and what a reading actually tells you.