Definition
An electronic oscillator circuit that uses the mechanical resonance of a vibrating quartz crystal to generate an electrical signal at a very precise and stable frequency. The crystal acts as a frequency-determining element, holding the output frequency within tight tolerances despite changes in temperature, voltage, or component aging.
Plain English
A circuit that produces a steady radio frequency by using a small piece of quartz crystal to keep that frequency from drifting. The crystal vibrates at one exact rate, and that rate sets the signal's frequency.
Context Anchor
Seen in avionics, radio transmitter and receiver descriptions, and navigation equipment that must stay accurately tuned.
Derivation
From 'crystal' (the quartz element that vibrates at a fixed rate when voltage is applied) and 'oscillator' (a circuit that produces a repeating electrical signal). The name simply describes what holds the frequency steady: a crystal does the controlling.
Why Pilots Care
Maintains exact transmission and reception frequencies so communications and navigation signals remain reliable without drift.
Analogy
A quartz crystal in this circuit acts a little like a tuning fork: when used correctly, it naturally vibrates at one steady rate and helps the equipment stay on pitch.
Intuition Check
“Crystal” does not mean decorative glass here. It means a small piece of quartz used inside electronic equipment to hold a steady frequency.
Example Sentence 1
The com radio uses a crystal-controlled oscillator to keep the transmitter locked precisely on the selected frequency.
Example Sentence 2
Technicians verify the crystal-controlled oscillator output before certifying the transponder for service.