At 06:12 PM 8/12/02 +0800, you wrote:
>We are using a 12.000MHz crystal in a timer circuit. It has 2 x 33pF load
>capacitors and the xtal is under the IC socket so the tracks to the uC are
>0.15" only.
>
>We want to measure the osc frequency to within 1Hz so we can adjust the
>load cap in one leg. Can someone tell us what test gear we need to be able
>to do this?

Suggest arranging an output of (e.g.) divide by 4, and then using a
reciprocal counter instrument to set the frequency.

Where did you pull that +/-1Hz spec out of? It's extremely tight
(0.08ppm), and the crystal frequency will drift more than that with
the slightest temperature change unless you are using a crystal oven.

Best regards,

Spehro Pefhany --"it's the network..."            "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com
9/11 United we Stand

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