[time-nuts] J06 HP-59992A time interval calibrator for HP-531xx counters

Poul-Henning Kamp phk at phk.freebsd.dk
Mon Jul 10 15:01:03 EDT 2017

In message <8fdafefb-3563-94be-e68d-63fe00164612 at earthlink.net>, jimlux writes:
>On 7/9/17 10:27 AM, Bob kb8tq wrote:
>> Hi
>> People *have* been known to sort MiniCircuits parts and use the “extras” in
>> something else. A certain major oscillator manufacturer once bought a bunch
>> of RPD-1’s , sorted them for the “one in a hundred” examples, and then returned
>> the rest for credit…… Somehow I doubt HP didi it quite that way.
>Some manufacturers will cherry pick for you.  Maybe the datasheet says 
>gain is 14 to 18 dB, and you order a batch that you want to be 15.5-16.5 
>dB.. They'll pick those out, but of course, now the remainder have a 
>hole in the distribution.  Particularly when you're buying high-rel or 
>space grade, where they have to 100% test anyway.

I've been told by somebody from HPs manufacturing in Europe that
there were one or two "magic" components where the manufacturer
would send their entire production to HP.

HP would test, measure and sort into four bins: "Failed", "Good",
"Really good" and "HP".

The first three bins got shipped back to the manufacturer.

He suspected that back at the manufacturer, the "Really good"
got a "MIL-GRADE" stamp :-)

Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.

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