[Elecraft] K2 Build Problem - No sidetone

[Don Wilhelm]

Sean,

U8 is seldom faulty.  Check your soldering - refer to the Soldering 
tutorial on the Builder's resource page at the Elecraft website if you 
have questions.  If suspicious, re-flow the soldering with a hot iron 
(750 to 800 deg F).  The solder should flow out to an almost invisible 
edge on both the solder pad and the component lead.  If it looks more 
like a ball on the solder lead, that is a sure sign that the solder pad 
did not receive enough heat.  If there is a lot of solder on the 
connection, that can be just as bad because it masks a poor solder 
joint.  Wick away the excess and re-solder.  Strive to have only a small 
fillet of solder on each solder pad.  Using a small diameter solder 
helps to control how much is applied.  I use .015 diameter, but the .020 
diameter is usually OK with care.  With larger solder diameters, by the 
time the solder flows, you already have too much solder on the connection.

73,
Don W3FPR

Sean Cavanaugh wrote:
> Hi all,
>
> I'm building my K2. I've just got to the step where everything gets 
> assembled and tested for the first time, and when testing the sidetone 
> I'm getting nothing.
>
> I've set the K2 to edit St L and varied the value from 0 to 255, 
> checking the voltages on U8. Pin 1 is 0v for all settings, and pin 4 is 
> also always 0v. The Vdd pin has 5.04v, and all ground pins show 
> connected to ground. It looks to me like U8 is bad.
>
> Any other ideas?
>
> Thanks es 73,
>
> Sean - VA5LF
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> ------------------------------------------------------------------------
>
>
> No virus found in this incoming message.
> Checked by AVG - www.avg.com 
> Version: 9.0.733 / Virus Database: 271.1.1/2741 - Release Date: 03/12/10 04:42:00
>
>