Re: gEDA-user: ngspice shot noise

[Gene Heskett <gene.heskett@xxxxxxxxxxx>]

On Tuesday 04 October 2005 05:57, Bob Paddock wrote:
>On Tuesday 04 October 2005 12:50 am, Gene Heskett wrote:
>> >> Virtually on the same day they sent us tens of thousands
>> >> 2N2907 transistors, labeled as such.  Days later when none of
>> >> the thousands of boards out of production worked correctly we
>> >> discovered that in those 2N2907 cases where really 2N2222
>> >> dies.
>> >
>> >For those who don't recognize the numbers .....  2N2097 and
>> >2N2222 are not interchangeable.  2N2907 is PNP.  2N2222 is NPN.
>> >Oops.
>>
>> Tell that to the nincompoops on the production lines.  I've had to
>> replace one with the other several times in brand new stuff.
>
>How would the production people know?  The part called for in all of
> their documentation called for 2N2907's (PNP).  The part was marked
> just like they had always been in the past, 2N2907.  What was inside
> the 2N2907 package was the 2N2222 (NPN).  They don't have X-Ray vision
> to see inside the package, don't think it would help if they did. 
> Testing every part before it goes on a board is not a practical
> solution in a production environment either.

Well, in the most recent case, the schematic called for 2n2222's, but
the boards were stuffed with 2n2907's.  They almost worked, but the
distortion was pretty bad.  Low voltage stuff.
 
-- 
Cheers, Gene
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
99.35% setiathome rank, not too shabby for a WV hillbilly
Yahoo.com and AOL/TW attorneys please note, additions to the above
message by Gene Heskett are:
Copyright 2005 by Maurice Eugene Heskett, all rights reserved.