[sdiy] Microphonics

[sleepy_dog at gmx.de]

 > I thought about using an accelerometer but it would have to be high 
sensitivity and low mass to work

How low a mass?
Maybe it's low enough if it connects with hand-soldered thin "coil wire" 
to its support components.
http://kionixfs.kionix.com/en/datasheet/KX122-1037%20Specifications%20Rev%204.0.pdf

This thing did pick up fingernail scratching on a desk on which the 
perfboard I had this on was lying.

- Steve


Am 22.01.2018 um 17:15 schrieb Tim Ressel:
> Got a weird one...
>
> An oscillator I designed is whining. Well, some units do it. It is 
> faint and you have to have your ear right up against the board to hear 
> it. But an end user complained so we had to investigate. Other 
> weirdness ensued but we got the customer taken care of.
>
> My question is: how to find where the whine is coming from? I tried 
> using a microphone but could not pick anything up. This is an ASM-1 
> type VCO (saw core) so there is a pulse train present. That could 
> explain the mic not picking it up. I tried putting my finger over 
> various components on the board with no luck. I thought about using an 
> accelerometer but it would have to be high sensitivity and low mass to 
> work.
>
> I am at a loss.  Any thoughts?
>