[time-nuts] Unified VCXO Carrier Board
csteinmetz at yandex.com
Wed Oct 28 18:38:43 EDT 2015
>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).
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