[time-nuts] how to find low noise transistors

KA2WEU at aol.com KA2WEU at aol.com
Sat Jul 18 18:36:13 EDT 2015

Good afternoon,
another low noise recommended transistor is the 
http://www.cel.com/pdf/datasheets/ne856m02.pdf and  for frequencies below 
10 Mhz
the 2N2857.  This nice  fact is that the AF and KF values  are published, 
the bad part is the the AF=1 value violates the law of  physics.
Be careful !
Who says EE is easy.
Best regards , Ulrich N1UL 
In a message dated 7/18/2015 3:56:53 P.M. Eastern Daylight Time,  
time-nuts at febo.com writes:

Good  afternoon, 

There is a problem in the literature that people confuse  the  "spot noise 
figure" and the "large signal " noise properties.  Here AF and KF  needs to 
known and considered.

Here is  the mathematical correct  formula in a Word for Windows Form   
attached file.
If you use it for publications, please quote me . Thanks  

My advise is take a BIP transistor , fT not much more then 20 x  operating  
frequency  (lower flicker component) and operate it  at 15 to 20 % of  

The BFG540 is amongst the best  Oscillators  oscillators  


Now  you outperform most colleagues 

73 de Ulrich  N1UL


In  a message dated 7/18/2015 1:19:57 P.M. Eastern Daylight Time,   
pete at petelancashire.com  writes:


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