[time-nuts] OCXO and fluctuations after EFC adjustment

[Taka Kamiya]

I'm STILL reading this, with interest.
I want to know the method of fault discovery, thought process that ensued, analysis conducted, testing process, and eventual root cause analysis.  We rely too much on automated processes and computers.  I want to know how engineers did more with less.  Before they are forever lost, we got to document it, or better yet, pass it on to newcomers.
I care more about how it was done before, not how it can be done better with this or that million dollar tool.

--------------------------------------- 
(Mr.) Taka Kamiya
KB4EMF / ex JF2DKG
 

    On Saturday, April 11, 2020, 8:59:32 PM EDT, Bob kb8tq <kb8tq at n1k.org> wrote:  
 
 Hi


> On Apr 11, 2020, at 8:10 PM, Richard (Rick) Karlquist <richard at karlquist.com> wrote:
> 
> 
> 
> 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

Indeed over the years, our experience was that feedback on components was
at best unwelcome and at worst a major waste of everybody’s time. Lots of 
“dialog” and very little benefit. Unless you are a precision crystal company, 
oscillator companies are *not* a big customer for any component outfit ….

Bob