[time-nuts] OCXO and fluctuations after EFC adjustment

[Richard (Rick) Karlquist]

On 4/11/2020 2:25 PM, Bob kb8tq wrote:
> Hi
> 
> Would you *really* want to read a book about how from August of 1986 to
> January of 1993 AVX NPO’s had some sort of issue ( not that the issue is
> clearly known, just that they are flakey) and that by 1994 the parts with
> values below 220 pf in 0805 seemed to be fixed?
> 
> Again, the task was never to *fix* a component, simply to sort out the parts
> that worked from the parts you didn’t want to use. The only feedback to the
> manufacturer was via the (lack of) purchase orders.
> 
> Somehow I doubt anybody would make it past the first page ….
> 
> Bob
> 

Back when before HP broke up into pieces, capacitor vendors considered
it a computer company and assumed that all capacitor orders were for
"computer grade" capacitors.  This envisioned huge motherboards with
thousands of bypass capacitors.  Like monitor specs where it is OK
for so many pixels to be bad, as long as 99% of the capacitors were
good ... ship them.  As long as the average leakage current met some
spec, it didn't matter if a few of them were very leaky.  The current
wouldn't be noticed.  Tempco and dissipation factor didn't matter.

We did actually give the manufacturer feedback, but it was not accepted
because we as an instrument division were not in their target market.
They didn't support repurposing.  It didn't matter than we were owned
by HP; we were using them for the wrong end use.  It's like those
disclaimers that say "We do not authorize for the life support
market" etc.

Some vendors flat out would not sell to our division although they
were fine with the computer divisions.

By now, few people besides Bob are still reading this. :-)

Rick N6RK