A Colpitts Oscillator circuit for testing crystal oscillators with a frequency counter.
G3PTO’s Xtal Tester is a simple circuit for measuring an (unknown) crystal’s fundamental resonant frequency with a frequency counter. It’s a very basic test, but good enough to verify the crystal is working and finding it’s frequency.
Of course, the reverse is also true: the circuit provides a nice reference signal for testing a frequency counter!
Credits and References
- Colpitts Oscillator - wikipedia
- G3PTO Xtal Tester - the original circuit reproduced here
- Single transistor crystal oscillator circuit - similar circuit, but with a single transistor
- Oscillator Crystal Test Circuit - Tony T’s demo of the circuit
- Victor VC3165 0.01Hz-2.4GHz Frequency Counter
- #123: Build a crystal oscillator from schematic thru prototype construction and testing - DIY - great tutorial by w2aew of building a similar circuit using the island cutter technique