Hello, my name is BreakingOhmsLaw and i suffer from GAS.
Today if have something for you, that probably is new even to this forum.
I present to you *drumroll* the Citizen CQT-101-C Quartz tester.
What is it? Well, basically its a frequency counter for wrist watches. It comes with a little pedestal for you to place a wrist watch on. Theres a hypersensitive microphone inside that listens for the watch ticking.
The ticks are measured with high precision, and the device shows the deviation of the watch in seconds per day.
There no CPU inside. It's just logic gates and counters, making clever use of an 4.320 MHz OCXO. In case you are wondering why:
24h x 60m x 60s x 50 = 4.320.000
I will be doing teardown and restore thread that i'll link in later.
Edit:
https://www.eevblog.com/forum/testgear/teardown-and-restauration-of-a-citizen-cqt-101-c-quartz-tester/ [ Specified attachment is not available ]