Newbie...

[honcho at paia.com]

>(I saw Paia is selling 
special transistors: "noise source npn silicon". Does anybody know 
whick 
transistor is it?) 
>>>
These are some 2N2712s that we've had laying around since the '70s and 
they've already been graded for noise. If we were to run out of them 
(which isn't likely in my lifetime) we'd probably shift to zeners. You 
can still find contemporary transistors that will give a nice thermal 
noise with little popcorn, but you have to go through a bunch.  An 
Amateur Scientist column in SciAm a few months ago just used a high 
value resistor and lots of gain for a noise source.

-John

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John Simonton                  PAiA Electronics, Inc
3200 Teakwood Ln.              honcho at paia.com
Edmond OK 73013                http://www.paia.com
405-340-6300                   fax 405-340-6378