[time-nuts] Old Crystal.

[Bob Albert]

 Is that a PR Peterson Radio logo?
    On Sunday, February 28, 2021, 03:53:32 PM PST, Dan Kemppainen <dan at irtelemetrics.com> wrote:  
 
 Hi All,

I've picked up a couple of old crystals. Mostly because they look neat. 
They are 1Mhz, in a glass tube. The quartz is ~25mm dia, at about 1 mm 
thick. Was able to get them to oscillate using a Colpitts circuit. They 
will oscillate at 2.851Mhz (probably some strange mode)  if given the 
chance.

I've been scouring my reference books here, and haven't had much luck 
finding any details on how one would even guess at the parameters of a 
quartz like this.

There area few numbers on them, 33 stamped on the side, 1000 (KHz???) on 
the top, 87 on the top, and hand written 501 (probably a SN). Digging on 
line, I'd guess an AT cut based on thickness. I'm guessing the 33 is 
capacitance in pF. 87, might be year.

If any of you have any suggestions on where to find information on how 
to get something like this to oscillate properly, guess at correct 
parameters, or even measure any of the parameters I would really 
appreciate it.

I'm sure these are really nothing special, but it would be neat to give 
them a fighting chance to show what they can or can't do without 
breaking them!

Thanks,
Dan
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