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

[Ralf Mardorf]

Gabriel Beddingfield wrote:
> 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
>   

On card A or X?
Why AM and not additive signals?