UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post

MrBungle · 11th Jan 2018, 6:10 pm

Yes they do age over time. The ones in digital clocks seem to be terrible. They are cut differently to other crystals as well apparently. I have a Casio watch from the 1980s that loses about 10 minutes a week.

Based on my observation of a large bag of 40m calling frequency crystals (7030KHz) which were dated early 1980s, they have drifted down by quite a bit with the correct load capacitance.

Usually you can add some capacitance to the circuit to tune them rather than replace the crystals however.

11th Jan 2018, 6:10 pm	#2
MrBungle Dekatron Join Date: Jun 2016 Location: London, UK. Posts: 3,687	Re: Quartz crystal accuracy over time Yes they do age over time. The ones in digital clocks seem to be terrible. They are cut differently to other crystals as well apparently. I have a Casio watch from the 1980s that loses about 10 minutes a week. Based on my observation of a large bag of 40m calling frequency crystals (7030KHz) which were dated early 1980s, they have drifted down by quite a bit with the correct load capacitance. Usually you can add some capacitance to the circuit to tune them rather than replace the crystals however.