any update on GSM interference issue

[Al Johnson]

On Tuesday 05 August 2008, arne anka wrote:
> > http://gadgets.boingboing.net/2008/08/02/kill-gsm-radio-buzz.html
> > Maybe that could provide a less invasive means to getting rid of the
> > problem?
>
> jOERG proposed using a ferrite bead on the wired headset a while ago in a
> german forum (freeyourphone.de or so).
> i am still trying to find one which is capable to be put on the included
> headset non-destructive (both the bead and the headset).
>
> ps: i was still under impression, the bead has to fit _around_ the cable
> -- the page says, it can be attached simple with tape as well.
> has someone a link explaining exactly what kind of voodoo that thing does?
> has it to have a hole?

The ferrite is increasing the common mode inductance of the cable because the 
ferrite has a better magnetic permeability than air. Taping the ferrite to 
the cable is a bit like a half turn on a ferrite rod. It will still affect 
the inductance, but not as much as if it went through a ferrite ring.