[time-nuts] Re: HP 10811A unusual appearance

[Tom Van Baak]

Hi Adrian, Rick, Bob,

The "flex" board is a thin ribbon-like PCB. It's shown in the manual [1] 
and described in the HPJ article [2], pages 26-28.

Jack Kusters (1937-2012) -- of SC-cut, 10811, 5071A, and GPSDO 
SmartClock fame -- once told me the flex board seemed clever at first 
but was prone to fail when used in instruments on [military] aircraft 
due to prolonged exposure to vibration. Or something like that. I'm not 
sure if that anecdote is related to the question here. I too would like 
to see a tear-down of the two oscillators mentioned.

/tvb

[1] 10811A/B Oscillator Operating & Service Manual:

http://hparchive.com/Manuals/HP-10811AB-Manual.pdf
http://leapsecond.com/museum/10811a/10811a.pdf

[2] Hewlett Packard Journal, March 1981:

https://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1981-03.pdf
https://archive.org/details/Hewlett-Packard_Journal_Vol._32_No._3_1981-03_Hewlett-Packard


On 8/24/2022 1:24 PM, Adrian Godwin wrote:
> If it's not too off-topic, what is a 'sculptured' flex circuit ?
> The 10811 I've taken apart has a 2D-shaped and folded flex circuit 
> that I'd consider 'conventional' - does a sculptured one have some 
> integral 3D shaping ?
>
>
> On Wed, Aug 24, 2022 at 7:46 PM Bob kb8tq via time-nuts 
> <time-nuts at lists.febo.com <mailto:time-nuts at lists.febo.com>> wrote:
>
>     Hi
>
>     I should have access to the supply dump some time in November.
>     My take was that they started off with a more exotic PCB approach
>     early on and simplified things a few years later. If I remember
>     correctly
>     the solder mask changed a bit at the change over as well.
>
>     Bob
>
>     > On Aug 24, 2022, at 6:13 AM, Matt Huszagh <huszaghmatt at gmail.com
>     <mailto:huszaghmatt at gmail.com>> wrote:
>     >
>     > Bob kb8tq <kb8tq at n1k.org <mailto:kb8tq at n1k.org>> writes:
>     >
>     >> There are at least two *very* different 10811 PCB’s out in the wild
>     >> in quantity. I don’t have access to the “stockpile” right now
>     so I can’t
>     >> say how the one in the picture compares to the commonly seen
>     >> varieties.
>     >
>     > If you do get access at some point and it's not too much trouble to
>     > check, I'd be interested to know more about this. Do you know
>     the reason
>     > for having two versions? Is it simply that one was an earlier
>     design and
>     > the other replaced it?
>     >
>     > Thanks
>     > Matt
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