Pulster fixe(s) and rework
joerg at openmoko.org
Wed Mar 4 14:27:06 CET 2009
Am Mi 4. März 2009 schrieb Helge Hafting:
> Joerg Reisenweber wrote:
> > Am So 11. Januar 2009 schrieb Alexandre Ghisoli:
> >> Le Sun, 11 Jan 2009 19:07:40 +0100,
> >> Konstantin <Chaosspawn23 at gmx.net> a écrit :
> >>> Matthias Apitz schrieb:
> >>>> Hello Christoph,
> >>>> Could you please also make an offer for the hardware buzz fix in DE:
> >>>> http://people.openmoko.org/joerg/GSM_EMI_noise/big-C_rework_SOP_rc2.pdf
> >>>> Would be great!
> >>>> Thx
> >>>> matthias (one of your happy GTA02 customers)
> >>> I second this one - offering the hardware fix for the freerunner
> >>> would be great :)
> >>> Regards,
> >>> Konstantin (One of your other happy GTA02 customers ;) )
> >> Yes, hardware fixes (rework) made by resellers would be great.
> >> By fixes, I mean :
> >> * GPS - SDIO fix (add a capacitor if I remember correctly)
> > There's a sw-fix for that, which mostly "just works"
> >> * Add a GSM IR resistor for deep sleep
> > Huh?
> >> * Change the led transistor power hungry stuff
> > Guys, this has been fixed for *ALL* FR ever sold!!!
> >> * fix the GSM buzz
> > ok, agree here.
> If I ship the phone somewhere to have a technician fix the buzz, I
> definitely want the "small capacitors on headset output" issue fixed too.
> The capacitor, combined with the resistance of earphones, form a
> high-pass filter.
> The cutoff frequency is 1/(2*pi*R*C), where R is headphone resistance
> and C is the size of the capacitor. The capacitor in the FR has been
> reported as 1 microfarad. My headset is about 40 ohm, which gives a
> cutoff frequency of about 4kHz.
> At 4kHz the sound is halved, and drops by 6db per octave below that.
> Above, the sound is almost normal. Unfortunately, most of the sound we
> hear is below 4kHz.
> A headset usually works down to about 20HZ. If I want the cutoff
> frequency there, a 200 microfarad capacitor is needed.
> Is there a plan for such a fix as well?
> Helge Hafting
Hey, you copied my mail from ~1year ago ;-)
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