markings on XTALs what do they mean?

On a sunny day (Mon, 30 Aug 2021 19:27:19 +0200) it happened Jeroen Belleman snipped-for-privacy@nospam.please wrote in <sgj4dn$uvg$ snipped-for-privacy@gioia.aioe.org>:

Googling finds this link for overtone oscilator design, with some math:

and this for the axis and vibration modes: that links to his paper: Piezo electric effect is very interesting, I designed and build an utrasonic antifauling thing for boats using piezzo transducers

And did experiments with 44 kHz piezos to measure airspeed:

I did a doppler system with those 44 kHz tranceivers that could detect if you blinked your eye. Then there is the usual distance meters (echo time) cheap from ebay.

And then where I encountered it was in the PAL 4.43 MHz delay lines for color TV, piece of glass:

I remember building a system to put color in a cheap Philips BW tape recorder, demonstrated it at work.. That system used 64 us delay lines to store red, green, blue.

Ayways crystals and piezos everywhere here...

For more precise timing I have a rubidium 10MHz generator..

Some stuff for discussion perhaps.

Too bad that most of the crystal makers have gone out of business. Unless you need one that is used in thousands of devices you will pay over $ 50 for one cut to your needs. They used to be relative inexpensive but with all the two way radios only needing one or two common ones instead of a dozen or so that were specially made not much volume or money to be made any more.

On a sunny day (Mon, 30 Aug 2021 16:21:28 -0400) it happened Ralph Mowery snipped-for-privacy@charter.net wrote in snipped-for-privacy@news.eternal-september.org>:

Yes, PLL chips into the GHz using 10 MHz reference.... OTOH a lot of xtal is on ebay / China.

I have a GPS derived 10MHz Frequency standard, and a 32 output DA with a DC to 350 MHz bandwidth, it was a video DA for HD video that I converted to 50 ohms. It used the same ICs that I had designed into my circuit, and was in a rack ount case for the price of a couple new ICs. The GPS unit also outputs time code for computer networks.