Pulster fixe(s) and rework

David Reyes Samblas Martinez david at tuxbrain.com
Wed Mar 4 17:58:30 CET 2009


any sop on the bass fix?

2009/3/4 Joerg Reisenweber <joerg at openmoko.org>:
> 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 ;-)
> /j
>
> _______________________________________________
> Openmoko community mailing list
> community at lists.openmoko.org
> http://lists.openmoko.org/mailman/listinfo/community
>
>



-- 
David Reyes Samblas Martinez
http://www.tuxbrain.com
Open ultraportable & embedded solutions
Openmoko, Openpandora, GP2X the Wiz, Letux 400, Arduino
Hey, watch out!!! There's a linux in your pocket!!!




More information about the community mailing list