[sdiy] Cheap frequency counter for oscillator calibration

[Andre Majorel]

On 2010-04-25 23:15 -0700, David G. Dixon wrote:

> Ah.  Thanks, Achim.  I didn't quite understand the concept of
> the "cent" of pitch.  Of course, this makes more sense than the
> mixed log-linear thing I was doing.

VCO precision is better expressed in cents (or PPM if you must)
than in percents. It's like THD -- I wish they'd switch to
something sensible like PPM or dB...

> In any case, +/- 5 cents seems like a lot or tracking error,
> doesn't it?  Particularly in the midrange.

There's hoping the error is concentrated below 50 Hz and above 3 kHz.
"+/-quite-a-few-cents over many octaves" is not a very meaningful
spec.

Have you managed to get rid of the 0.8 Hz error at 880 Hz ?

-- 
André Majorel http://www.teaser.fr/~amajorel/