Was it the Reagan and Gorby years when the phrase "Trust but Verify"
came into use? I have had friends and ham buddies in the past who gave
me stuff, too. And I've gone into surplus stores and purchased parts
that were still on tape feed, so I would guess that the parts were good,
even if somewhat old. In this case one has a reasonable assurance that
the parts are good. But if your ham buddy gives you some parts, there
is no assurance at all. He could've bought them at a ham flea market,
from someone who stole them from work, and the parts were good, so the
seller passed on the 'discount' to the buyer.
Or the seller could've been an employee of a QC inspection dept where
they regularly pick over parts and throw the rejects in the dumpster.
This could have a favorable outcome. The rejection process could be set
so that the parts, say 5% resistors, are selected for tighter tolerance.
Anything outside of + or - 2% are rejected. So what the buyer gets is a
bunch of mostly good parts, but there is a big hole in the statistical
distribution curve where there are no parts in the + to - 2% section.
So if the buyer tests them, he sees two concentrations, -5% to -2%, and
+2% to +5%. That's not all that bad, but it does show that the parts
hzve been picked over.
And of course there is the possibility that the 'hole' in the middle is
even bigger. If all the buyer sees are 5% parts in the -5% or below,
and +5% and above, then he has a bunch of rejects[1]. And of course
there are outcomes that can be somewhere in between those extremes. So
with some testing, the rejects can be rejected, and the good parts can
be saved. And hopefully those rejects end up in the dumpster, and not
on the table at the next ham flea market, or worse, in some surplus
store. "Stuff happens," dontcha know!
[1] Like they say, one man's junk is another man's treasure. If those
rejected resistors were marked 1% tolerance, but fell outside of + or -
1%, they would be perfectly acceptable for use in a circuit where only a
5% resistor was required. Or in my case, the 2 dozen 0.1% resistors
could be rejected for 0.1%, but work just fine for 1% purposes. If the
seller is truthful and tells the buyer that the 1% parts are out of
tolerance but can be used for 5% purposes, then the seller is honest
about it, even tho he's selling known rejects. But if he's
misrepresenting the rejects as good parts, then he's dishonest and
should be dealt with to prevent it from happening again. But many
sellers (especially surplus) won't 'know' that they sell rejects; they
use the excuse that they have no way of testing, so they couldn't have
known they are rejects. Yeah, right. Something else from the Reagan
years: "Plausible deniability."
Oops! Looks like it's from long before.
http://www.kavinay.com/dictionary/plausible_deniability.php
