Am Fr 31. Oktober 2008 schrieb Angus Ainslie: > On Thu, Oct 30, 2008 at 8:18 PM, Andy Green <[EMAIL PROTECTED]> wrote: > > > Angus, I talked to Candy here in .tw the last few days about this, she > > actually did the work to perform the tests Joerg is talking about. > > > > Did she use a 100uF cap ? > > > > > > One thing you can try that is quite simple and easy is to override > > MICBIAS net by a ~1.5V battery on it to 0V. She told that this alone > > removes the buzz, it would be good to know if you can reproduce. > > > > > That probably would work. I don't think I'm going to try it as I have had > some results with the cap fix. > > Initially I tried using the 100uF cap that was suggested. It kind of worked. > there was no buzz but there was also almost no gain from the mic.
You HAVE to replace R4303 0R with a 2k2 !! (check R from mic housing MIC4301:2 to GND! Has to be 2k2, will read 0R usually) Otherwise this cap fix CAN NOT work. Refer to schematics, please. > Voice > wouldn't get transmitted but blowing on the mic would. I removed the 100uF > cap and then used a 1uF cap. Ther buzz was gone, a slight hum still remains > that might have been coupling from one of the other devices in the room. I'm > going to try in a less signal saturated environment later. > > I think I'd also like to try it with MICBIAS raised to the 0.9 multiplier. Probably won't change that much - interesting to hear of your results nonetheless. > Is that done in the bootloader or in kernel space ? Could someone generate a > an updated kernel with the higher mic bias ? > > Prep the ground plane for the 100uF cap. The to photos are the same the > smaller one is just for bandwidth reduced diets. > > http://handheldshell.com/DSCN0386_small.JPG > http://handheldshell.com/DSCN0386.JPG > > Cap in place > > http://handheldshell.com/DSCN0387_small.JPG > http://handheldshell.com/DSCN0387.JPG > > Jumper wire attached You also could have used the empty pad more near to the left side (R4304) Wire should be kept as short as possible (to reduce "antenna") > > http://handheldshell.com/DSCN0388_small.JPG > http://handheldshell.com/DSCN0388.JPG > > With the 1uF cap. > > http://handheldshell.com/pa310077_small.jpg > http://handheldshell.com/pa310077.jpg > > Thanks > Angus cheers jOERG
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