[time-nuts] HP quality

[J. Forster]

Over the years, I've seen perhaps 10,000 pieces of electronic gear. In
that time I can remember 4 "out of factory" failures: In no particular
order:

The unsoldered part in an HP LASER Interferometer I posted previously.

In an HP "Communications Sweep Oscillator" covering 3.7 - 4.2 and 5.9-6.5
GHz, there was a screw loose (really!) in the output amp MMIC. A
microscopic inspection showed it had never been tightened at the factory.
The MMIC was trashed.

In a Data General semiconductor memory board for a Nova 3, 30-50 IC leads
were never wave soldered.

In a Test Station for a Raytheon AMRAAM missile, there were unsoldered
joints on a switch.

In all cases, I think the units passed inspection and were delivered to
customers.

ears ago, when I was building space payloads, I was told by a guy at MIT's
Lincoln Labs: "You cannot inspect in quality."

He was right, IMO.

Best,

-John

========================

[snip]
> On the 'bad out of factory' issue, I never saw in HP or Agilent equipment,
> but one Sony TV once had 5 pins on the tuner never soldered - the factory
> whistle must have sounded after pin 5 and the thing was tested and shipped
> the next day. This was a lesser line out of Mexico - two XBRs have been
> running for 10+ yrs without a glitch.
>
> Jose
>
>
> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
> Behalf Of Geoff Blake
> Sent: Sunday, September 11, 2011 1:33 AM
> To: time-nuts at febo.com
> Subject: Re: [time-nuts] HP quality
>
>>> That is not a unique incident.
>>>
>>> I'm interested in LASER Interferometry. Attached is a pic I took of an
>>> HP
>>> 5529A LASER head.
>>>
>>> (Aside: If anybody is interested, there is a Yahoo Group for LASER
>>> Interferometer fans)
>>>
>>> Note the two leads to CR5 near the top, center of the pic. They go to a
>>> feedback photocell and obviously have never been trimmed or soldered.
>>>
>>> The unit ran fine that for several months before suddenly failing.
>>> Soldering the leads fixed the LASER head.
>>
>> It was not always this way.  Today I stumbled on a 1965 HP 738BR
>> Voltmeter Calibrator at my favorite surplus electronics store.  I
>> offered $20.00 and it was accepted.
>>
>> This unit is based on vacuum tubes!  I got it home, plugged it in, and
>> it is still in spec on the DC range.  The AC part is not working - I
>> suspect the small incandescent lamp that stabilizes the oscillator.
>>
>> I may end up junking the vacuum tube half.  The other part of the
>> instrument, in a separate compartment, has a precision 40 step
>> attenuator with a 10^6 / 1 range (300 Volts to 300 uVolts) which I will
>> certainly keep.
>>
>> Best regards,
>
> No please don't junk the valve part, it would be be waste of a lovely
> instrument.
>
> However that's not the topic.
>
> I first met a HP 3582 LF SA when it came into the cal lab from a
> remote site, just out of warranty. Apart from being out of cal, the
> was a brief comment, "intermittent channel 1". We had not seen one
> before and being the "guv" I got to play first.
>
> Yes there was an intermittent fault and it seemed vibration sensitive.
> After I had figured how to drive it (what's a FFT analyser - what's a
> FFT? but I was young then.) I could confirm the fault and I had even
> found the diagnostics in the manual.
>
> Running diagnostic 1 I determined that the fault was in IC1 or IC3 and
> using diagnostic 2 I narrowed it down to IC1 or IC2, so suspecting a
> loose IC1 I put a rather large thumb and pressed - the fault
> disappeared  Remove thumb and it was back!
>
> In for a penny, in for a pound, I pulled the chip and yes, even I
> could spot the doubled up pin, so I gently straightened it and that
> was the cure. Later I was told that the fault was there since
> delivery, but they could not afford to spare it at the the time.
>
> (Please note the (IC) names have have been changed to protect my memory.)
>
> Geoff G8GNZ
>
> --
> ###############################################
> Geoff Blake,   G8GNZ    JO01fq:   Chelmsford,  Essex,  UK
> <geoff at palaemon.co.uk>    or   <melecerties at gmail.com>
> Using Linux: Ubuntu 11.04 on Intel or Debian on UltraSparc
> and even on the NAS.     Avoiding Micro$oft like the plague.
> ###############################################
>
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