I too tried that and equally failed even with 52dB gain. I suspect that part of the trick is how the piezo is mounted: Quite possibly if mounted in a circular form held only at the edges, with the watch crown touching the centre it might be more sensitive than if the centre is clamped to the watch with the edges free?
Regards, David Partridge -----Original Message----- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Robert Darlington Sent: 18 April 2014 19:49 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Measuring the accurcy of a wrist watch Commercially they use piezo transducers ("bender disks") in direct contact with the watch to hear them tick. I did my best to build one up several weeks ago. I could hear ants walking but my cheap swiss movement was just too quiet. It was amazingly quiet, even going through a preamp and dialing the vertical amp to 11 on the scope. They must have them sized for resonance a little closer to the spectrum given off by the movement. -Bob _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
