I did the big-c buzzing rework myself, with the precious help of a

much more smd-experienced colleague.

It was very difficult to replace the resistor because of the proximity

of the components around the mic. A very sharp soldering iron is

critical.

I used a 1k resistor (didn't have a 2k2 of the same size at hand), and

a 100uF/10V tantalum capacitor.

So far, so good! The buzz seems to be gone for good. :)

One caller has reported that I sounded like "at the bottom of a pit",

but this can be the other older issue...
Citando Paul Fertser :
> Joel Newkirk  writes:

quoted text
>> Still waiting for an answer from OM. (I posted a question in this thread

>> Friday regarding Tanatalum instead of Ceramic cap - the difference being

>> __PLACEHOLDER__0_.25 vs  each in qty 100, and my radio guy thinks Tant is a good choice

>> for filtering, but waiting for word from Steve or Jeorg)

>

> Joel, Joerg overlooked your question on the community mailing list,

> you should have asked at hardware list instead. I asked him on IRC:

> here's the answer:

>

> 12:57 < PaulFertser> DocScrutinizer: could you please answer a

> question wrt capacitor type for the gsm buzz fix? Joel Newkirk asks

> whether he can use tantalum instead of ceramic ones as tantalum are

> much cheaper and he's going to perform a rework on a reasonable

> quantity of units (IIRC).

> 13:00 < DocScrutinizer> PaulFertser: we don't have any tantalum caps

> here, and I would guess they are just too big. I was about to suggest

> a free caeramic cap for everyone asking for it. actually I'll bring a

> handfull of those to Germany on Sunday

> 13:00 < DocScrutinizer> PaulFertser: technically there is nothing

> wrong with tantalum

> 13:01 < DocScrutinizer> though I'd guess they are somewhat harder to

> solder, as they're basically electrolytic caps and so won't stand much

> heat

> 13:01 < PaulFertser> DocScrutinizer: if you don't mind, i'm going to

> post your answer on the community mailing list in the corresponding

> thread.

> 13:02 < DocScrutinizer> go ahead, you're welcome

> 13:02 < DocScrutinizer> just quote this dialog is fine

> 13:04 < DocScrutinizer> also, to whom it may concern, I plan to join

> 25C3 congress in Berlin, and maybe rework a couple of devices there

> for free, or at very least give away caps

>

> --

> Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!

> mailto:fercerpav@gmail.com

>

>

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