PENDULUM DRIVE

Only in Bloggsworld.

X-cut are pretty good at 25C +/- 10 and incredibly good at +/-5C since the TC has a tiny quadratic dependence on temperature away from 25C.

It is quite difficult to get cheap Xtal 32kHz clock chips to run out by that much even with incorrect loading. Given how cheap and ubiquitous they are there is no excuse for getting it wrong by that much.

Even if they did it is quite hard to make the crystal frequency that much higher!

I agree all the watches and digital clocks I have fail when the LCD becomes too faint to read without ever drifting off time sync.

The only ones I have ever seen drift badly were because the "designer" failed to put the right capacitor load network around the crystal or was over driving it in a way that guarantees a much shortened life.

krw > I don't own a watch but the big deal krw > is not 30 seconds, rather having krw > to reset it at all. LOL Some are very NON-INTUITIVE.

That's what I thought. For all I know maybe they used a bad crystal.

Jeff (Who still remembers grinding war surplus WWII FT-243 xtals on a sheet of glass with abrasive powder, to move them up into the 40 meter ham band, before I learned how to make a VFO. )

Jeff

Boraxo ;-) ...Jim Thompson

Boraxo - Righto!

Thanks for the mammaries...

Jeff (Who still has a small cardboard box with about a dozen of those FT-243 xtals in it, those and a stack of QSL cards is all that's left of my once extensive collection of ham radio stuff. Somehow I can't bear to toss those in the trash, I assume my heirs will do that for me.)

Yep. I still have some FT-243's as well. My wife does the honors when I'm not looking... she doesn't take kindly to me designating my "junk" as "antiques" >:-} ...Jim Thompson