The original 10811's used so-called "sculptured" flex circuits.
That was a disaster and then they changed to conventional ones.
I don't know if any of the sculptured ones shipped.  If they
did, it might explain why the boards look different.  It
could be that no sculptured versions officially shipped, but
you have a prototype that escaped from the mother ship
without a serial number.

Rick N6RK

On 8/22/2022 9:22 PM, Matt Huszagh via time-nuts wrote:

On 8/23/22 7:18 AM, Richard (Rick) Karlquist via time-nuts wrote:

At JPL, we dispose of all kinds of "e-waste" in large bins. So if you
had a bunch of lab breadboards that have long outlived their usefulness
then they go in the bin.  There are people who buy the bins (I think
they're auctioned off) and sort through them, or just grind them up and
extract the metals. The vast majority of whats in there is stuff like
old cables that have cracking insulation, boxes of 30 year old parts of
dubious quality and provenance. I could easily see HP working
similarly.   For what it's worth, at JPL, it's against the rules for
employees to dumpster dive - There's apparently a govt originated policy
on this, to reduce the possibility of the equivalent of a restaurant
worker throwing away a $400 whole fish, to be rescued later by a
confederate.

I used to have tubes and trays of some IC or component in my desk or on
a shelf in a cabinet in a lab, where we needed half a dozen or so, and
we bought 10-20 to have spares.  We never did work out a good way to
keep track of "lab spares for breadboarding", and periodically (every 10
years or so), they'd go on a "let's clean out the cabinets" movement,
and we'd purge the stuff that a)was clearly degraded; b)we had way too
many of (we had cabinets full of weird shaped brackets to mount
something in 19" racks, but nobody could remember what it was they were
for); c) components that were supplied as part of an experimental
contract (vendor goes and makes 30 pieces of something, we test 3, and
they don't work, so the box just goes on the shelf).  As people retire,
the knowledge of "what is that iridited box from a company that doesn't
exist any more?" goes away, and stuff winds up in e-waste.  Or the data
sheets were purged in an earlier activity, so you know what it is, but
no idea how to use it.

OTOH, there are regular calls at amateur organizations like San
Bernardino Microwave Society to give a new home to a storage container
full of 30+ year old stuff accumulated over a life time.  So in that
case, the mystery box just gets a new home, until it gets readopted
again. Typically, the stuff moves when a particular storage reaches it's
physical limit of capacity (or, "you need to get rid of that shed,
because we're building a pool" kind of events).

"Richard (Rick) Karlquist" richard@karlquist.com writes:

Thanks Rick. Was it a disaster in the sense of reliability?

Matt

Hi

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.

Bob

I never knew exactly what the problem was, but I didn't get the

impression it was reliability.  That would imply that they shipped

OK and then died in the field.  I never worked on the 10811 myself,

but sat near the ME who would yell at Buckbee Mears (the mfr

of these things) on his phone all the time.  It wasn't advisable to

actually inquire about this problem because that would rile up the

ME.

Rick

On 2022-08-23 08:08, Matt Huszagh wrote:

Bob kb8tq kb8tq@n1k.org writes:

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

The only two "very different" PCB's I am aware of are the

original sculptured flex circuit and the conventional flex

circuit that superceded it early on, due to problems with

the sculptured flex vendor, as I have previously stated.

Rick Karlquist
N6RK

On 2022-08-24 07:13, Matt Huszagh via time-nuts 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

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@lists.febo.com> wrote: