[time-nuts] Unified VCXO Carrier Board

Charles Steinmetz csteinmetz at yandex.com
Wed Oct 28 18:38:43 EDT 2015


Bruce wrote:

>I have a bunch of LM329's purchased from a large distributor.I guess 
>I should make some noise measurements.Some have even been installed 
>in low noise regulators.

I'd think if you used LM329s as bad as the ones Gerhard tested in 
sensitive circuits, it would have been obvious on testing.

The probability that you receive genuine parts is much higher if you 
buy from a major distributor (for many parts, including almost all 
hard-to-find semiconductors, if you buy on ebay the probability 
approaches zero very closely).  But big distributors are not immune 
from the problem.

I sometimes buy ten-turn WW potentiometers from China that purport to 
be Bourns 3590S parts but are, in fact, counterfeit, right down to 
the molded-in "Made in Mexico" legend.  I have to throw away about 
25% of them, but even so I get ten for the price of one genuine, 
made-in-Mexico Bourns and the selected ones are good enough for many 
applications.  I will not use counterfeit semiconductors, because 
invariably the very specs that you want the part for are the ones it 
doesn't meet (which means that after many attempts I no longer buy 
semiconductors on ebay, EVER, from ANYBODY).

Best regards,

Charles




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