[HBQRP] CW filter issue.

[david cripe]

Hi All.  

I'm building up my CW filter, and came across one bug.  When I powered it up, it was a dead short across the 9v input.  I cut power traces to the LM386, the TLC274 and pulled the 220u cap. and it was still a short.  I inspected the board under a microscope, and found nothing amiss.  Finally, I tied a 12v lead acid battery across the 9v input, heard a tiny 'pop' and the short cleared itself.  

Evidently, there was a small copper whisker left from the etching causing the short.  Hopefully, this is the only time this fault occurs on any of our boards.  Otherwise. this indicates a possible QC issue from the board house.

73 Dave NM0S