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HP48G Crystal / Timer Accuracy
08-10-2019, 03:13 PM (This post was last modified: 08-10-2019 03:22 PM by TomC.)
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HP48G Crystal / Timer Accuracy
As has been well documented here, the HP48 timekeeping is 'not too hot'.

As we know, the crystal is a 'standard' 32768Hz crystal that is multipiied up to get the calculators '4MHz' operating frequency. (I wonder if this multiplication varies with OS version? I'm currently studying a ver R and a ver L.)

Has anyone studied or actually executed a replacement of the crystal?
- The physical package is an industry standard type and quite large, so it should be easy mechanically.
- In selecting a replacement, I suspect series resistance, capacitance are critical, but I'm no expert here.
- What was the spec of the original crystal?

I will pursue finding a more accurate replacement (assuming one exists).

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HP48G Crystal / Timer Accuracy - TomC - 08-10-2019 03:13 PM

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