GSM-noise "buzz" issue - replace R4401 by bead?

Joerg Reisenweber joerg at openmoko.org
Mon Oct 13 02:44:01 CEST 2008


Contamination path seems via R4408. Complete removal of both R (plus any other 
components connecting this trace to the remaining circuit) didn't stop buzz 
though - we think RF is coupled to a nearby trace or component near trace end 
on R4408 inside can, near Wolfson.
So probably when removing doesn't help, replacing with a ferrite bead won't 
either. But we never tested it. If you're keen to do it, your report on it is 
highly appreciated, no matter whether positive or negative result.

/jOERG


Am Mo  13. Oktober 2008 schrieb Laurie Bradshaw:
> Hi, I've also been suffering with this buzz problem, and have been
> wondering if replacing R4401 with a suitable 220R smd ferrite might
> achieve the desired result whilst hopefully being at least a little
> easier than trying to retrofit a ferrite bead to JK4401.
> 
> 2008/10/13 Joerg Reisenweber <joerg at openmoko.org>:
> > Am Mo  13. Oktober 2008 schrieb shawnzier at gmail.com:
> >> Sorry about the dumb question. I was just wondering if bluetooth headsets
> > would be affected by this buzz problem.
> >
> > No. Will work without buzz
> > /jOERG
> >
> > _______________________________________________
> > hardware mailing list
> > hardware at lists.openmoko.org
> > http://lists.openmoko.org/mailman/listinfo/hardware
> >
> >
> 


-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 194 bytes
Desc: This is a digitally signed message part.
Url : http://lists.openmoko.org/pipermail/hardware/attachments/20081013/d23a0ed5/attachment.pgp 


More information about the hardware mailing list