[LAD] A little quiz about audio measurements...

[Gabriel Beddingfield]

On Fri, May 28, 2010 at 12:39 PM, Gabriel M. Beddingfield
<gabrbedd at gmail.com> wrote:
> The 100 Hz (being 2x 50Hz, the power freq. in Italy)
> suggests that it is probably related to some manner of
> power supply.  However, I have no theory why we're
> getting 2x 50Hz (and I think I need one :-)).

Doh!  When the AC wave is rectified, it results in a signal that is 2x
the freq. because the negative part gets inverted.  That's why we see
100 Hz instead of 50 Hz.

-gabriel