USB microscopes for very small SMT

[krw]

Phil Hobbs wrote:
Joerg wrote:
[...]

And pretty soon we'll both be "senior gleaners" ;-)

I never liked math, only learned what I really needed. Sometimes that
still haunts me. I had to calculate an elliptic filter with a weird
load on there this morning. Boy, had that math stuff become rusty.
Almost took a pick-axe to get it going again.

Nah, I just turned 49. Besides, I possess the fountain of youth--my
beloved wife is older than I am.

Same here!

...and she gets the AARP junk mail. ;-)

Out here they bombarded with several membership offers and then it
stopped. Is there much of an advantage to become a member? I've heard
from people that they received lots of junk mail afterwards.

Hotel room discounts, which can be substantial, are the only
advantage I've found. I'm not sure it's worth funding their lobby
though.

 

[Joerg]

Phil Hobbs wrote:
Joerg wrote:
[...]

And pretty soon we'll both be "senior gleaners" ;-)

I never liked math, only learned what I really needed. Sometimes that
still haunts me. I had to calculate an elliptic filter with a weird
load on there this morning. Boy, had that math stuff become rusty.
Almost took a pick-axe to get it going again.

Nah, I just turned 49. Besides, I possess the fountain of youth--my
beloved wife is older than I am.

Same here!
...and she gets the AARP junk mail. ;-)

Out here they bombarded with several membership offers and then it
stopped. Is there much of an advantage to become a member? I've heard
from people that they received lots of junk mail afterwards.

I use only the AARP prescription insurance. Seems OK. BUT I'm going
to move all my prescriptions to Sam's Club... $4 for most stuff, even
better prices than Walgreen's on second tier and non-covered. BUT
keep the insurance for any catastrophic event.

So if I understand it correctly AARP would only make sense for folks who
are already on Medicare. Our Kaiser HSA-type plan has meds included but
I am considering whether to ratchet down to the non-med covered plan.
It's a one-way street, when some ailment kicks in they won't let you
back in. Would shave off $50-$60/month and we never really need
anything. But who knows.

For Medicare supplemental I use Mutual of Omaha (Plan F)... only had
to pay for one lab test (cholesterol test ordered more than once a
year... jerk doctor, now I'm wary) in the nearly 5 years I've had it.

Good for you. But I am often wondering how an elderly person without an
engineer's wits and without family/friend support can possibly find
their way through that maze. There's lots of folks who don't even have a
high school education and even if they do it was half a century ago.

 

[Joerg]

On Fri, 19 Dec 2008 16:45:16 -0800, Joerg

krw wrote:
Phil Hobbs wrote:
Joerg wrote:
[...]

And pretty soon we'll both be "senior gleaners" ;-)

I never liked math, only learned what I really needed. Sometimes that
still haunts me. I had to calculate an elliptic filter with a weird
load on there this morning. Boy, had that math stuff become rusty.
Almost took a pick-axe to get it going again.

Nah, I just turned 49. Besides, I possess the fountain of youth--my
beloved wife is older than I am.

Same here!
...and she gets the AARP junk mail. ;-)

Out here they bombarded with several membership offers and then it
stopped. Is there much of an advantage to become a member? I've heard
from people that they received lots of junk mail afterwards.

I use only the AARP prescription insurance. Seems OK. BUT I'm going
to move all my prescriptions to Sam's Club... $4 for most stuff, even
better prices than Walgreen's on second tier and non-covered. BUT
keep the insurance for any catastrophic event.

So if I understand it correctly AARP would only make sense for folks who
are already on Medicare.

Can you belong to AARP _before_ you're "of age"?

AFAIK beginning at 50 years old.

I never had doctor office visits and medication coverage before
retirement... just catastrophic coverage insurance... it paid out a
bundle though when I had a heart attack at age 58. Of course I never
thought something like that would happen to me... so be wary!

Oh yeah, we'll keep medical. It's just that paying an extra $50+ a month
for prescription coverage seems highish when you never use any meds.

My doctor pretty much jumps to my tune now, has stopped trying to
foist Lipitor on me, particularly since my recent BP was 122/78 ;-)

Unfortunately my recent so called prostatitis diagnosis may actually
be that I tore something while tree climbing ;-) CT Scan on Tuesday.

Sort of funny how everyone castigates American medicine, but today I
walked my doctor's order for a CT scan into the imaging lab, got
scheduled for Tuesday morning. Try that in Brit-land ;-)

Or our northern neighbors. IIRC they even started a "wait time reduction
fund".

 

[krw]

On Fri, 19 Dec 2008 16:45:16 -0800, Joerg

krw wrote:
Phil Hobbs wrote:
Joerg wrote:
[...]

And pretty soon we'll both be "senior gleaners" ;-)

I never liked math, only learned what I really needed. Sometimes that
still haunts me. I had to calculate an elliptic filter with a weird
load on there this morning. Boy, had that math stuff become rusty.
Almost took a pick-axe to get it going again.

Nah, I just turned 49. Besides, I possess the fountain of youth--my
beloved wife is older than I am.

Same here!
...and she gets the AARP junk mail. ;-)

Out here they bombarded with several membership offers and then it
stopped. Is there much of an advantage to become a member? I've heard
from people that they received lots of junk mail afterwards.

I use only the AARP prescription insurance. Seems OK. BUT I'm going
to move all my prescriptions to Sam's Club... $4 for most stuff, even
better prices than Walgreen's on second tier and non-covered. BUT
keep the insurance for any catastrophic event.

So if I understand it correctly AARP would only make sense for folks who
are already on Medicare.

Can you belong to AARP _before_ you're "of age"?

Age 50.

I never had doctor office visits and medication coverage before
retirement... just catastrophic coverage insurance... it paid out a
bundle though when I had a heart attack at age 58. Of course I never
thought something like that would happen to me... so be wary!

I've had full coverage for 35 years and never used it for myself
until I left (three days for A-Fib) and that was under COBRA. My
wife did use the insurance a couple of times, though other than the
three weeks in the hospital with the brat, no hospitalization.

My doctor pretty much jumps to my tune now, has stopped trying to
foist Lipitor on me, particularly since my recent BP was 122/78 ;-)

Isn't Lipitor for cholesterol (rather than BP)? My BP was through
the roof (260/180) when I was admitted with A-Fib a couple of years
ago. I've since been on a beta-blocker and it's been reasonable.
They had me on an ACE inhibitor too, but that was attacking my
joints so I stopped taking it. The beta-blocker seems to be
handling alone it because I've usually been between 110/60 and
130/80. ...unless there is a doctor in the room.

Unfortunately my recent so called prostatitis diagnosis may actually
be that I tore something while tree climbing ;-) CT Scan on Tuesday.

Tree climbing? Aren't you a little...

Sort of funny how everyone castigates American medicine, but today I
walked my doctor's order for a CT scan into the imaging lab, got
scheduled for Tuesday morning. Try that in Brit-land ;-)

I had a CT scan on an hour's notice. The echo cardiogram wasn't
showing what they wanted to see so sent me for the CT scan. No
emergency, just wanted to take a good look at the heart before they
discharged me.

 

[Joerg]

Tin? A lot of ours were milled out of 1/2" aluminum sheet. The
older designs were in custom aluminum boxes with threaded inserts for
the board mounts & feedthroughs.

We've got to stop being this wasteful with our resources. Except for
situations where mechanical precision is important (optics, injections
pumps, and such) there is usually no reason to use milled material.

 

[Joerg]

You're forgetting microwave filters (and other things) there... anything that
has to handle any decent amount of power is often something like a bunch of
coupled cavity resonators, all nicely milled out of a chunk of aluminum and
then plated. Or heck, even invar or kovar for those really demanding
applications where money is no limit!

Ok, that falls under "needs mechanical precision". Although until
recently I had a tunable oscillator in the lab. Projetado e fabricado no
Brasil, cheap steel, most holes drilled willy-nilly and screws
force-jammed into them, none of the holes seemed to lined up, looked
horrible inside. Yet it was super stable. Hats off to the designers (but
not to the production guys).

We have all of one product that uses a milled case... it's a wideband
isolation amplifier, and I believe the rationale for the milled case was that
it contains a handful of shielded sections, and it was cheaper to just CNC
mill out the cases to create each shieled area than to have someone custom cut
(or chemically etch) some tin and then pay our guys to sit there installing
the individual shields (and either solder or otherwise create solid seams).

I suggest to really price that out. Unless it is a very low volume
product simple steel constructions can be remarkably cheap. I convinced
several clients to ditch their aluminum card cages and do custom steel.
Same for milled parts. Some thought this was going to cost a lot, only
to learn that it was actually cheaper, not any heavier, and almost
turned their equipment into a tank.

Did you see that photo of the Tektronix SD20 guts that John posted? Beautiful
milled case there... ;-)

No, only the creme brulee post. Almost made me trudge over to the fridge
again where the gingerbread is. If it was on a.b.s.e. that's history for
me. My ISP pulled binaries because of an overzealous AG (we all know who
that is).

 

[Joerg]

Joel Koltner wrote: [snip]

Did you see that photo of the Tektronix SD20 guts that John posted? Beautiful
milled case there... ;-)

No, only the creme brulee post. Almost made me trudge over to the fridge
again where the gingerbread is. If it was on a.b.s.e. that's history for
me. My ISP pulled binaries because of an overzealous AG (we all know who
that is).

Pulled binaries so he can spend all his time reversing the electorate
on Prop 8 ?

No, it was the guy in New York. The one here has most likely
self-destructed his career with that "move".

 

[Joerg]

ftp://jjlarkin.lmi.net/SD20.zip

That looks freaking expensive. I am surprised they still use milled
material.

and here's my sampler...

ftp://jjlarkin.lmi.net/Sampler1.JPG

Neato! But the copper clad looks like whoever soldered it together had
half a pack of Marlboros right next to the board ;-)

 

[Joerg]

Gold plated, no less. The SD20 sold for $4840 in 1998.

Ouch. I guess those days are almost over now. Except for clients such as
large research labs that always seem to have oodles of money at year end.

Just doing my little year-end Digikey order. Sez no DHL pickup today on
account of the weather. Must be tough out there.

I etched and soldered that myself. Dual-channel (only one stuffed)
half-bridge sampler, with symmetric sampling impulses generated by an
SRD and shorted transmission lines. Got 5 GHz analog bandwidth. I'd
love to go into the sampling scope business, but it's hard to compete
with ebay.

But you could make and sell little TDR boxes

 

[Joerg]

I heard on the news that DHL was shutting down its US operation.

http://www.cnbc.com/id/27642899

AFAIK that may not affect international shipments (yet).

 

[Joerg]

We didn't build throwaway equipment. Some has seen well over 30
years of continuous service. Also, the milled design was not only
smaller, the milled housing carried away the heat. We built microwave
equipment, where the housing figured into the overall performance. If
we used a cheaper housing, we had to add a lot of parts to stabilize the
design. ...

For that kind of gear it is sometimes ok. The first design I took part
in after my masters degree was an ultrasound machine. I still see them
popping up at used med gear dealers. Those things last, despite not
being made of milled stuff.

... A cheaper housing was tested for out low phase noise
synthesizer. They stayed with the nickel plated design with a DB 25
connector and over 30 soldered in feed through capacitors, because the
new case had too many stray currents that affected phase noise.

Stray currents? That usually points to some design issues. I've helped
ham radio folks build microwave stuff in <gasp> "Danish Butter Cookies"
tin cans. Worked marvelously but was very bad for our wastelines because
the original contents had be eaten.

A CNC machine can spit out milled aluminum parts for less than some
sheet metal designs can be cut & folded. The aluminum chips are
collected, and reused, so there is little waste. If it was a high volume
part it would be cast, then milled but most of ours were bought at 100
or less at a time.

From an energy point of view still a rather low efficiency process. But
it's good that you guys at least re-used the chips. I have seen them
being chucked into the garbage.

 

[John Devereux]

(Cool board - is the big grey patch just solder or did you do
something else to it?)

I really should, a tiny USB or Ethernet box, to sell for $1200 maybe.
The hardware is dirt cheap and fairly easy; I have a deconvolution
algorithm that makes ugly TDR pulses into beautiful TDR pulses, which
makes the design a lot easier. The real pain is the software.

Well if you will write everything in assembler...

 

[Joerg]

I really should, a tiny USB or Ethernet box, to sell for $1200 maybe.
The hardware is dirt cheap and fairly easy; I have a deconvolution
algorithm that makes ugly TDR pulses into beautiful TDR pulses, which
makes the design a lot easier. The real pain is the software.

Although you could limit the use to non-Vista systems. With respect to
Vista I am seeing a widespread non-acceptance among my clients (same in
my office).

But if you design one it needs to be absolutely rugged because it's
going to be used by cable crews. Out here they usually show up in 4WD
trucks with coarse-thread tires, for good reason.

 

[Joerg]

This was for deep space telemetry for NASA, not amateur radio
service. The low noise floor was one of our best selling features. It
was cleaner than some single channel crystal controlled designs. A tin
enclosure was thinner, and required the use of PEM fasteners to mount
the PC board. Over time, they developed resistance between the different
metals. The thicker, nickel plated housing allowed the hardware to be
silver soldered, and the stiffer case let us use a Monel gasket. A
cheaper case would have dropped the cost less than $25 on a $1000+
module. It was the heart of five of our product lines.

Yeah, I did a lot of nickel plating as well. Not very expensive and
otherwise quite excellent. Plating is a regular subject almost every
time I receive an EMI emergency call from a new client. Typically it's
all anodized because it looks cool, and nothing is conductive :-(

We had it done by a large outside machine shop that recycled all
their scrap metals. (Cutting oil, and all.) When you generate it by
the ton, its foolish to throw it away.

Believe me, some still do it. Sad. It's like dentists chucking old gold
crowns. At a billing rate well north of $500/hour I guess it doesn't
matter ...

 

[John Devereux]

]

(Cool board - is the big grey patch just solder or did you do
something else to it?)

I just tinned it. The bare copper tarnishes quickly.

What I really need is a stack of copperclad scraps that are gold
plated.

I don't think the board manufacturer I use charges extra for gold
plating, at least not for small quantities.

We often have boards panelized and scored so they "snap off" (or you
separate them with the proper machine). Anyway these have these "scrap
bars" around the edges.

Now there seems no reason why I could not have these gold plated. I
was thinking of doing a load of those little SMT adapter pieces too,
there. (I think maybe you showed us some once).

[...]

 

[JosephKK]

We've got to stop being this wasteful with our resources. Except for
situations where mechanical precision is important (optics, injections
pumps, and such) there is usually no reason to use milled material.

Nobody sane has thrown out machining cuttings for decades, the recycle
value has been way too high. Hell, even in school on the 1960's it
was standard.

 

[JosephKK]

I've seen it done. In machine shops. Sometimes I asked why. Too much
hassle, they said :-(

I bet you know people who would like to supplement their income by
doing the recycling for them. Try getting them together.

 

[Spehro Pefhany]

I bet you know people who would like to supplement their income by
doing the recycling for them. Try getting them together.

There's the little issue of coolant on the swarf-- better make sure
you're not becoming an unlicensed toxic waste handler. 8-(.


Best regards,
Spehro Pefhany

 

[JosephKK]

On Sat, 03 Jan 2009 08:44:50 -0800, the renowned JosephKK



There's the little issue of coolant on the swarf-- better make sure
you're not becoming an unlicensed toxic waste handler. 8-(.


Best regards,
Spehro Pefhany

Possible issue for sure. But then the machining company has some
"'splaining to do". You won't know until you ask. Besides, if there
is any problem waste incorporated in the swarf it must go to a
properly licensed facility (in the USA and most of Europe).