"Michael A. Terrell" on Tue, 23 Sep 2014
03:26:31 -0400 typed in rec.crafts.metalworking the following:

Larry Jaques wrote:

That's cool. I envy your vast knowledge/experience base. (I only made
it to half vast.) Had I wanted to go to college, I likely would have
taken both electrical and mechanical engineering courses. My parents
offered to pay the price. But I was too fed up with people, being a
hermit by nature. I chose auto mechanic tech school over college, as
machines don't talk back.


Sure they do. You can even carry on conversations with some of them.
I told more than one piece of equipment that if it didn't behave I would
scrap it for parts.

But I find that a lot of machines hate it when you
anthropomorphize them.
--
pyotr filipivich
"With Age comes Wisdom. Although more often, Age travels alone."

Larry Jaques on Tue, 23 Sep 2014
07:19:34 -0700 typed in rec.crafts.metalworking the following:
On Mon, 22 Sep 2014 21:27:52 -0700, pyotr filipivich
wrote:

Larry Jaques on Mon, 22 Sep 2014
19:50:54 -0700 typed in rec.crafts.metalworking the following:

I did drill and tap a lot of holes and learn to bend sheet
metal accurately on a manual brake.

Great. I finally got back on my little HF (Harbor Freight, not high
freq) TIG yesterday and once again repaired the steel mount bracket
for Dad's old Craftsman circular saw. I hadn't penetrated well enough
the first time and it only lasted two months of very light work. This
time, I turned the amperage down and spent some time pooling the area
so I got a good, deep puddle. What I didn't burn through the first
time looks, um, fairly good now. (no picture requests, please
Anyway, the more metalworking, plasma cutting, and TIG welding I do,
the more I like it.

I wonder what kind of solar/battery setup I'll need to continue to use
that thing once the grid goes down... Time to start looking at 240v
inverters, I guess.

The is rec.crafts.metalworking - you should be planning on the
steam powered generator setup! From Scratch! Refine your own
scratch, too!

Bbbut, I was talking about Tiggin', wholely on topic on a metalworking
group. Wouldja like to hear more about how I stuck the electrode and
welded with it still contaminated?

Ummm, no. Sorry, but I don't know enough about TIG welding to be
able to laugh at the right places. B-)

I purely do wish it had a HF start
mode, but it's a scratcher. The copper-plated filler rod helps
immensely, though.

Besides being tres cool, for something so wildly hot, steam is
totallyunsustainableandwilldrownpolarbearsinmelte dicejustaskAlgoreyup.

Use a solar power to heat the steam. Even better - cause there is
no coal involved.

Or you could make your own nuclear power plant. No carbon
emissions at all!
--
pyotr filipivich
"With Age comes Wisdom. Although more often, Age travels alone."

"Michael A. Terrell" on Tue, 23 Sep 2014
13:25:54 -0400 typed in rec.crafts.metalworking the following:

Larry Jaques wrote:

On Tue, 23 Sep 2014 03:26:31 -0400, "Michael A. Terrell"
wrote:


Larry Jaques wrote:

That's cool. I envy your vast knowledge/experience base. (I only made
it to half vast.) Had I wanted to go to college, I likely would have
taken both electrical and mechanical engineering courses. My parents
offered to pay the price. But I was too fed up with people, being a
hermit by nature. I chose auto mechanic tech school over college, as
machines don't talk back.


Sure they do. You can even carry on conversations with some of them.
I told more than one piece of equipment that if it didn't behave I would
scrap it for parts.

What I meant was that they don't talk back...much.


You've lead a very sheltered life.

It is okay to talk to the aircraft.
It is okay for them to talk back.
But, do not start arguing with them - that is a bad sign.

"true Story" - Capt Schiebe gets on his tanker, and checks the log
"repaired bullet damage". Asks what was the meaning of this - the are
in Eastern Washington. Well, seems that one of the ramp rats [pulling
guard duty] got into an argument with one of the planes and it said
something and he shoot. "But it wasn't our aircraft- we were just an
innocent bystanders!"
--
pyotr filipivich
"With Age comes Wisdom. Although more often, Age travels alone."

Larry Jaques on Tue, 23 Sep 2014
09:09:45 -0700 typed in rec.crafts.metalworking the following:
On Tue, 23 Sep 2014 10:39:09 -0400, "Jim Wilkins" wrote:
"Michael A. Terrell" wrote:
Larry Jaques wrote:
That's cool. I envy your vast knowledge/experience base. (I only
made it to half vast.) Had I wanted to go to college, I likely would
have taken both electrical and mechanical engineering courses. My
parents offered to pay the price. But I was too fed up with people, being a
hermit by nature. I chose auto mechanic tech school over college,
as machines don't talk back.
Sure they do. You can even carry on conversations with some of them.
I told more than one piece of equipment that if it didn't behave I
would scrap it for parts.

Machines with intermittent faults behave perfectly when I come near
them.

But only when we're there troubleshooting them, right? BTDT.

All depends. Sometimes, the machines need to know that they are
in the presences of One Who Knows.
--
pyotr filipivich
"With Age comes Wisdom. Although more often, Age travels alone."

"Michael A. Terrell" wrote in message
m...

Jim Wilkins wrote:


So did HP. My early-70's 8555A spectrum analyzer is a masterpiece
of
both electronic and mechanical design. It even has a Magic Crystal
for
a heart
http://en.wikipedia.org/wiki/YIG_sphere

Then they lost their way on the scopes with keypads and a single
control dial that took two minutes to change any setting. I have
one
because it sold cheap but much preferred their Infinium with
separate
knobs for each function.


I like my Tek 2465A scopes. The newer HO spectrum analyzers could
print the screen, but the setup was six menus deep and it only
worked
with a couple HP printers. Engineers would come to the production
floor
to ask us to set one up for them.

I bought Tek until they 'lost the process" around 2000. The HP
Infinium was a good substitute, and it had an Internet browser so as a
sight gag I could leave it hooked to a prototype circuit but
displaying weather radar.

I also wrote a screen saver for it that imitated a PPI air search
radar screen with occasional bogies flying by, and one with the Matrix
waterfall of random characters.

I can learn to use LeCroy, Phillips or Hitachi but not really to like
them.

I couldn't pass up the 1 GSa HP digital storage scope for $300 at
auction. The down side was that the company being mostly liquidated
was my employer.
-jsw

On Tue, 23 Sep 2014 15:40:26 -0700, pyotr filipivich
wrote:

Larry Jaques on Tue, 23 Sep 2014
09:09:45 -0700 typed in rec.crafts.metalworking the following:
On Tue, 23 Sep 2014 10:39:09 -0400, "Jim Wilkins" wrote:
"Michael A. Terrell" wrote:
Larry Jaques wrote:
That's cool. I envy your vast knowledge/experience base. (I only
made it to half vast.) Had I wanted to go to college, I likely would
have taken both electrical and mechanical engineering courses. My
parents offered to pay the price. But I was too fed up with people, being a
hermit by nature. I chose auto mechanic tech school over college,
as machines don't talk back.
Sure they do. You can even carry on conversations with some of them.
I told more than one piece of equipment that if it didn't behave I
would scrap it for parts.

Machines with intermittent faults behave perfectly when I come near
them.

But only when we're there troubleshooting them, right? BTDT.

All depends. Sometimes, the machines need to know that they are
in the presences of One Who Knows.
--
pyotr filipivich
"With Age comes Wisdom. Although more often, Age travels alone."

And experienced end users know when to simply walk away when we are
talking to our sick machines. Newbies look askance and start looking
for a butterfly net with paniced eyes.

Shrug

Gunner

"At the core of liberalism is the spoiled child,
miserable, as all spoiled children are, unsatisfied,
demanding, ill-disciplined, despotic and useless.
Liberalism is a philosophy of sniveling brats."
PJ O'Rourke

On Tue, 23 Sep 2014 18:44:18 -0400, "Jim Wilkins"
wrote:

"Michael A. Terrell" wrote in message
om...

Jim Wilkins wrote:


So did HP. My early-70's 8555A spectrum analyzer is a masterpiece
of
both electronic and mechanical design. It even has a Magic Crystal
for
a heart
http://en.wikipedia.org/wiki/YIG_sphere

Then they lost their way on the scopes with keypads and a single
control dial that took two minutes to change any setting. I have
one
because it sold cheap but much preferred their Infinium with
separate
knobs for each function.


I like my Tek 2465A scopes. The newer HO spectrum analyzers could
print the screen, but the setup was six menus deep and it only
worked
with a couple HP printers. Engineers would come to the production
floor
to ask us to set one up for them.

I bought Tek until they 'lost the process" around 2000. The HP
Infinium was a good substitute, and it had an Internet browser so as a
sight gag I could leave it hooked to a prototype circuit but
displaying weather radar.

I also wrote a screen saver for it that imitated a PPI air search
radar screen with occasional bogies flying by, and one with the Matrix
waterfall of random characters.

I can learn to use LeCroy, Phillips or Hitachi but not really to like
them.

I couldn't pass up the 1 GSa HP digital storage scope for $300 at
auction. The down side was that the company being mostly liquidated
was my employer.
-jsw

Ouch!!!


"At the core of liberalism is the spoiled child,
miserable, as all spoiled children are, unsatisfied,
demanding, ill-disciplined, despotic and useless.
Liberalism is a philosophy of sniveling brats."
PJ O'Rourke

"Michael A. Terrell" wrote in message
m...

Today, .01% are easy to get.
LaSer trimmed can be even closer.

You can buy 'as marked' but they are only that value at a specific
temperature and they aren't cheap. Considering that the first
standard
was 50%, .01% is a 5000% improvement. I've bought reels of .o1% on
Ebay
for well under one cent per part.

GM solved its problem by changing from analog op amps and comparators
to digital microcontrollers in the ABS module. I heard that the analog
ABS design had come from someone who created it in his garage and then
dropped dead before he had properly documented it.

The bigger accuracy issue in building high-precision automated test
equipment, where I used the 0.01% resistors, was actually capacitance.

While dual-slope A/D converters may automatically compensate for
temperature drift, the storage caps in the input Sample-and-Holds
don't. They matter because they are very small to track fast and the
FET that isolates the cap from the signal to maintain a steady voltage
during the conversion also couples unwanted charge into the cap from
the voltage swing on its gate. We could couple a trimmed compensating
charge switched by the gate control into the sample cap but the
tempcos weren't matched since the compensating cap was a small patch
on the circuit board.

The larger capacitance error source was dielectric absorption, when a
polar capacitor dielectric acts slightly like a chemical battery and
takes a short while to fully charge or discharge after the voltage
changes. When you have only 5mS to set up and make a measurement it
becomes a serious concern. We had to have W.L.Gore make custom
Teflon-wrapped reed relays to cut the dielectric absorption in the
relay matrix that configures each test down so it didn't degrade
accuracy.

-jsw

On Tue, 23 Sep 2014 19:49:00 -0400, "Jim Wilkins"
wrote:

"Michael A. Terrell" wrote in message
om...

Today, .01% are easy to get.
LaSer trimmed can be even closer.

You can buy 'as marked' but they are only that value at a specific
temperature and they aren't cheap. Considering that the first
standard
was 50%, .01% is a 5000% improvement. I've bought reels of .o1% on
Ebay
for well under one cent per part.

GM solved its problem by changing from analog op amps and comparators
to digital microcontrollers in the ABS module. I heard that the analog
ABS design had come from someone who created it in his garage and then
dropped dead before he had properly documented it.

The bigger accuracy issue in building high-precision automated test
equipment, where I used the 0.01% resistors, was actually capacitance.

When I was working QA at a manpack radio mfgr, we got a new HP LCR
meter. I was amazed at how much capacitance and/or inductance were
added to leads during tests just by getting near them or touching
them. I can't imagine designing a multilayer PCB, with all those
stray waves invading other spaces. Ditto ATE.


While dual-slope A/D converters may automatically compensate for
temperature drift, the storage caps in the input Sample-and-Holds
don't. They matter because they are very small to track fast and the
FET that isolates the cap from the signal to maintain a steady voltage
during the conversion also couples unwanted charge into the cap from
the voltage swing on its gate. We could couple a trimmed compensating
charge switched by the gate control into the sample cap but the
tempcos weren't matched since the compensating cap was a small patch
on the circuit board.

Layered directly on the board, or soldered on?


The larger capacitance error source was dielectric absorption, when a
polar capacitor dielectric acts slightly like a chemical battery and
takes a short while to fully charge or discharge after the voltage
changes. When you have only 5mS to set up and make a measurement it
becomes a serious concern.

I'll bet that was fun to figure out, even without the cycle-time
constraint.


We had to have W.L.Gore make custom
Teflon-wrapped reed relays to cut the dielectric absorption in the
relay matrix that configures each test down so it didn't degrade
accuracy.

Teflon sheds electrons? Or is it just a good insulator? (Or are those
the same question?

--
Give me the luxuries of life.
I can live without the necessities.
--anon

On Tue, 23 Sep 2014 12:13:02 -0700, Gunner Asch
wrote:

On Tue, 23 Sep 2014 07:27:12 -0700, Larry Jaques
wrote:


Gonna take a pretty fair amount of power. Think about a genny that can
be run from a stream or steam.

I had it set all the way down on 1 to weld a 3/32" bracket. That
seems to be my^C^Cone weak point. Determining the welder power
setting. I'm now using much less power to weld and it's getting easier
each time. I really should practice more. sigh


Or wood gas. You know..I do have a 300 amp Hobart with a 6 cylinder
Chrysler engine just collecting dust..right? Might make a great wood
gas welder.

How do you get the 6 logs down into the cylinders to burn, mon?

Making wood gas sounds like a really toxic, smelly, and very messy
proposition.

REread my last sentence above, then read pg 58 (GOTO pg 73 via the
Wiki function), then tell me to make one anyway. I dare ya.

http://commons.wikimedia.org/wiki/Fi..._Emergency.pdf

--
Give me the luxuries of life.
I can live without the necessities.
--anon

On Tue, 23 Sep 2014 15:40:26 -0700, pyotr filipivich
wrote:

Larry Jaques on Tue, 23 Sep 2014
07:27:12 -0700 typed in rec.crafts.metalworking the following:

Or wood gas. You know..I do have a 300 amp Hobart with a 6 cylinder
Chrysler engine just collecting dust..right? Might make a great wood
gas welder.

How do you get the 6 logs down into the cylinders to burn, mon?

Making wood gas sounds like a really toxic, smelly, and very messy
proposition.

Naw. You bake the wood, catch the 'gas' which contains various
volatile compounds, which then gets used as a fuel gas. "Is simple" -
and a chance to use those might welding skills (obMetalworking)

Rightio!


And when the wood is done - you have charcoal to fire up the next
batch.

See my message to Gunner, page 58/9 for maintenance and hazards.
It'll be hard enough to stay clear of toxins after the Fall.
I don't need to bring them into my life on purpose, y'know?

--
Give me the luxuries of life.
I can live without the necessities.
--anon

On Tue, 23 Sep 2014 12:30:08 -0400, wrote:

On Tue, 23 Sep 2014 09:09:45 -0700, Larry Jaques
wrote:

On Tue, 23 Sep 2014 10:39:09 -0400, "Jim Wilkins"
wrote:

"Michael A. Terrell" wrote in message
news:a8udndHx09syvbzJnZ2dnUVZ_uKdnZ2d@earthlink .com...

Larry Jaques wrote:

That's cool. I envy your vast knowledge/experience base. (I only
made
it to half vast.) Had I wanted to go to college, I likely would
have
taken both electrical and mechanical engineering courses. My
parents
offered to pay the price. But I was too fed up with people, being a
hermit by nature. I chose auto mechanic tech school over college,
as
machines don't talk back.


Sure they do. You can even carry on conversations with some of
them.
I told more than one piece of equipment that if it didn't behave I
would
scrap it for parts.

Machines with intermittent faults behave perfectly when I come near
them.

But only when we're there troubleshooting them, right? BTDT.
Generally, the last week I own a car, after I've decided to get rid
of it, the car runs better thanr years - - -

That's usually when the damned things die on you: before you get the
money. "You're not going to sell _me_, you SOB!"

--
Give me the luxuries of life.
I can live without the necessities.
--anon

On Tue, 23 Sep 2014 13:25:54 -0400, "Michael A. Terrell"
wrote:


Larry Jaques wrote:

On Tue, 23 Sep 2014 03:26:31 -0400, "Michael A. Terrell"
wrote:


Larry Jaques wrote:

That's cool. I envy your vast knowledge/experience base. (I only made
it to half vast.) Had I wanted to go to college, I likely would have
taken both electrical and mechanical engineering courses. My parents
offered to pay the price. But I was too fed up with people, being a
hermit by nature. I chose auto mechanic tech school over college, as
machines don't talk back.


Sure they do. You can even carry on conversations with some of them.
I told more than one piece of equipment that if it didn't behave I would
scrap it for parts.

What I meant was that they don't talk back...much.


You've lead a very sheltered life.

Hayull no! I buy more refined machinery, sir.

--
Give me the luxuries of life.
I can live without the necessities.
--anon

On Tue, 23 Sep 2014 12:51:44 -0700, Gunner Asch
wrote:

On Tue, 23 Sep 2014 09:42:21 -0400, Tom Gardner
wrote:

On 9/21/2014 10:12 PM, Gunner Asch wrote:
On Mon, 22 Sep 2014 00:32:43 +0000 (UTC), Cydrome Leader
wrote:

I deviced to take apart an orignal Nikon F 35mm camera today, to see
what's inside.

About 5000 parts is the answer, for a completely mechanical 35mm camera.


WHY???!!! did you smash a Nikon F body???

They are still worth in excess of $200 each and for us
collectors..they are freaking priceless!!!


"At the core of liberalism is the spoiled child,
miserable, as all spoiled children are, unsatisfied,
demanding, ill-disciplined, despotic and useless.
Liberalism is a philosophy of sniveling brats."
PJ O'Rourke



I've got a boatload of Canon 35mm if interested.

Perk!!

ah..what do you have?

No, no, Gunner. He did NOT say he had a boatload of 35mm cannons.
He's talking cameras.

--
Give me the luxuries of life.
I can live without the necessities.
--anon

On Tue, 23 Sep 2014 19:15:52 -0700, Larry Jaques
wrote:

On Tue, 23 Sep 2014 12:13:02 -0700, Gunner Asch
wrote:

On Tue, 23 Sep 2014 07:27:12 -0700, Larry Jaques
wrote:


Gonna take a pretty fair amount of power. Think about a genny that can
be run from a stream or steam.

I had it set all the way down on 1 to weld a 3/32" bracket. That
seems to be my^C^Cone weak point. Determining the welder power
setting. I'm now using much less power to weld and it's getting easier
each time. I really should practice more. sigh


Or wood gas. You know..I do have a 300 amp Hobart with a 6 cylinder
Chrysler engine just collecting dust..right? Might make a great wood
gas welder.

How do you get the 6 logs down into the cylinders to burn, mon?

Making wood gas sounds like a really toxic, smelly, and very messy
proposition.

REread my last sentence above, then read pg 58 (GOTO pg 73 via the
Wiki function), then tell me to make one anyway. I dare ya.

http://commons.wikimedia.org/wiki/Fi..._Emergency.pdf

What..the carbon monoxide poisoning bit if you put it into a closed
and sealed garage?

Blink blink...you expected something different?

Run a Coleman lantern (white gas or propane) in the sealed cabin of a
boat and see if there are different results.

Yet I fail to see folks not using such lanterns (properly)

As for it being messy...of course it CAN be. Same with using a
fireplace. You ARE burning wood afterall.

Gunner

"At the core of liberalism is the spoiled child,
miserable, as all spoiled children are, unsatisfied,
demanding, ill-disciplined, despotic and useless.
Liberalism is a philosophy of sniveling brats."
PJ O'Rourke

On Tue, 23 Sep 2014 19:18:05 -0700, Larry Jaques
wrote:

On Tue, 23 Sep 2014 15:40:26 -0700, pyotr filipivich
wrote:

Larry Jaques on Tue, 23 Sep 2014
07:27:12 -0700 typed in rec.crafts.metalworking the following:

Or wood gas. You know..I do have a 300 amp Hobart with a 6 cylinder
Chrysler engine just collecting dust..right? Might make a great wood
gas welder.

How do you get the 6 logs down into the cylinders to burn, mon?

Making wood gas sounds like a really toxic, smelly, and very messy
proposition.

Naw. You bake the wood, catch the 'gas' which contains various
volatile compounds, which then gets used as a fuel gas. "Is simple" -
and a chance to use those might welding skills (obMetalworking)

Rightio!


And when the wood is done - you have charcoal to fire up the next
batch.

See my message to Gunner, page 58/9 for maintenance and hazards.
It'll be hard enough to stay clear of toxins after the Fall.
I don't need to bring them into my life on purpose, y'know?

So you will get plenty of exercise walking to town or afield and
towing a sled or wagon with your goods and cargo. Its good for you!

Afterall...if you manage to get a couple hundred pounds of canned
goods..you can make multiple trips.

And for that trip to the dispenary..after severing your finger with
a knife in the kitchen...not a problem.

Might be something of a problem after falling off the roof and
getting that pesky green stick fracture of your arm..but hey..walking
a number of miles in the cold with your humerus sticking out of your
sleeve side ways...not a big problem for a ecologically considerate
guy!

Gunner



"At the core of liberalism is the spoiled child,
miserable, as all spoiled children are, unsatisfied,
demanding, ill-disciplined, despotic and useless.
Liberalism is a philosophy of sniveling brats."
PJ O'Rourke

On Tue, 23 Sep 2014 19:25:12 -0700, Larry Jaques
wrote:

On Tue, 23 Sep 2014 12:51:44 -0700, Gunner Asch
wrote:

On Tue, 23 Sep 2014 09:42:21 -0400, Tom Gardner
wrote:

On 9/21/2014 10:12 PM, Gunner Asch wrote:
On Mon, 22 Sep 2014 00:32:43 +0000 (UTC), Cydrome Leader
wrote:

I deviced to take apart an orignal Nikon F 35mm camera today, to see
what's inside.

About 5000 parts is the answer, for a completely mechanical 35mm camera.


WHY???!!! did you smash a Nikon F body???

They are still worth in excess of $200 each and for us
collectors..they are freaking priceless!!!


"At the core of liberalism is the spoiled child,
miserable, as all spoiled children are, unsatisfied,
demanding, ill-disciplined, despotic and useless.
Liberalism is a philosophy of sniveling brats."
PJ O'Rourke



I've got a boatload of Canon 35mm if interested.

Perk!!

ah..what do you have?

No, no, Gunner. He did NOT say he had a boatload of 35mm cannons.
He's talking cameras.

Indeed he did say cameras (Perk!!)

Gunner

"At the core of liberalism is the spoiled child,
miserable, as all spoiled children are, unsatisfied,
demanding, ill-disciplined, despotic and useless.
Liberalism is a philosophy of sniveling brats."
PJ O'Rourke

"Cydrome Leader" wrote in message
...

Has anybody come across any other products, new or old that just appear to
be some sort of socialist work program, and not about making a machine
that works, at a reasonable price and that can be easily serviced?


Personal computer operating systems

On 9/22/2014 11:27 PM, DoN. Nichols wrote:
On 2014-09-22, Steve W. wrote:
Cydrome Leader wrote:
Gunner Asch wrote:
On Mon, 22 Sep 2014 00:32:43 +0000 (UTC), Cydrome Leader
wrote:

I deviced to take apart an orignal Nikon F 35mm camera today, to see
what's inside.

About 5000 parts is the answer, for a completely mechanical 35mm camera.

WHY???!!! did you smash a Nikon F body???

They are still worth in excess of $200 each and for us
collectors..they are freaking priceless!!!

It had no pentaprism, so it's not actually worth anything. I still have
one left that is complete.

Pentaprisms can be found -- or waist level finders -- or sports
finders -- or ...

while I'm typically no fan of destroying stuff like this, it is the only
option when no service manuals are available, and you can't hire and old
guy to let you watch a repair.

The question still stands. When do companies design stuff to be overly
complex. What's the real end goal?

To make the camera manufacturable. A lot of those parts are for
tuning the speeds and motions to allow for variations in spring
constants and the like. The cheaper cameras have fewer parts, and less
accuracy as a result -- especially as they age.

Of course, today a lot of that is tuned using microprocessor
chips built into the camera. :-)

Service manuals for many Nikon cameras, including the F

http://arcticwolfs.net/downloads.php

Thank you! I've now downloaded manuals for all the Nikon
SLR cameras I have. (Do you know of a similar site for the Zeiss
Contax?)

Thanks,
DoN.

I now have a Fujji camera that uses my old F lenses and new modern
electronic lenses from Nikon. And mine runs on AA cells.
Martin

On Tue, 23 Sep 2014 20:08:18 -0700, Gunner Asch
wrote:

On Tue, 23 Sep 2014 19:15:52 -0700, Larry Jaques
wrote:

On Tue, 23 Sep 2014 12:13:02 -0700, Gunner Asch
wrote:

On Tue, 23 Sep 2014 07:27:12 -0700, Larry Jaques
wrote:


Gonna take a pretty fair amount of power. Think about a genny that can
be run from a stream or steam.

I had it set all the way down on 1 to weld a 3/32" bracket. That
seems to be my^C^Cone weak point. Determining the welder power
setting. I'm now using much less power to weld and it's getting easier
each time. I really should practice more. sigh


Or wood gas. You know..I do have a 300 amp Hobart with a 6 cylinder
Chrysler engine just collecting dust..right? Might make a great wood
gas welder.

How do you get the 6 logs down into the cylinders to burn, mon?

Making wood gas sounds like a really toxic, smelly, and very messy
proposition.

REread my last sentence above, then read pg 58 (GOTO pg 73 via the
Wiki function), then tell me to make one anyway. I dare ya.

http://commons.wikimedia.org/wiki/Fi..._Emergency.pdf

What..the carbon monoxide poisoning bit if you put it into a closed
and sealed garage?

No, the daily/weekly/monthly cleaning, toxins, etc. It's a dirty and
time-consuming procedure. BTDT. Pass, for now, thanks.


Blink blink...you expected something different?

Run a Coleman lantern (white gas or propane) in the sealed cabin of a
boat and see if there are different results.

g


Yet I fail to see folks not using such lanterns (properly)

As for it being messy...of course it CAN be. Same with using a
fireplace. You ARE burning wood afterall.

Hate 'em. My fireplace is boarded over for several reasons. First is
that it's cracked, so flames might reach my attic. Second, I removed
and sold the insert (which they torched the beautiful 1/4" steel plate
heatilator to get it in the first place deep sigh). Third is that I
hate the smoke fires create into the house, even in well built stoves
and hearths. (Might as well be smoking again. No, thanks.) For all of
you who will say "My stove doesn't let any smoke into the house.",
I'll just file you with the folks who say "My dog doesn't bark." and
"Gun control works." gd&r

Yes, it's a viable way to produce gas for a vehicle. It's just not
one I wish to use for the time being. I reserve the right to change
my tune (in a hurry, if necessary) soon after the Fall.

--
Give me the luxuries of life.
I can live without the necessities.
--anon

On Tue, 23 Sep 2014 20:13:28 -0700, Gunner Asch
wrote:

On Tue, 23 Sep 2014 19:18:05 -0700, Larry Jaques
wrote:

On Tue, 23 Sep 2014 15:40:26 -0700, pyotr filipivich
wrote:

Larry Jaques on Tue, 23 Sep 2014
07:27:12 -0700 typed in rec.crafts.metalworking the following:

Or wood gas. You know..I do have a 300 amp Hobart with a 6 cylinder
Chrysler engine just collecting dust..right? Might make a great wood
gas welder.

How do you get the 6 logs down into the cylinders to burn, mon?

Making wood gas sounds like a really toxic, smelly, and very messy
proposition.

Naw. You bake the wood, catch the 'gas' which contains various
volatile compounds, which then gets used as a fuel gas. "Is simple" -
and a chance to use those might welding skills (obMetalworking)

Rightio!


And when the wood is done - you have charcoal to fire up the next
batch.

See my message to Gunner, page 58/9 for maintenance and hazards.
It'll be hard enough to stay clear of toxins after the Fall.
I don't need to bring them into my life on purpose, y'know?

So you will get plenty of exercise walking to town or afield and
towing a sled or wagon with your goods and cargo. Its good for you!

Afterall...if you manage to get a couple hundred pounds of canned
goods..you can make multiple trips.

And for that trip to the dispenary..after severing your finger with
a knife in the kitchen...not a problem.

Might be something of a problem after falling off the roof and
getting that pesky green stick fracture of your arm..but hey..walking
a number of miles in the cold with your humerus sticking out of your
sleeve side ways...not a big problem for a ecologically considerate
guy!

Hey, if you want dioxins and soot and nasty smell all over you, fine.
I guess that's not too far beyond being a ciggy smoker. g
just shakes head

--
Give me the luxuries of life.
I can live without the necessities.
--anon

On 2014-09-23, Gunner Asch wrote:
On Mon, 22 Sep 2014 21:09:31 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Gunner Asch fired this volley in
m:

[ ... ]

Ive still got a pair of Omega D2s if you want them. With the 4x5 and
35mm condensers. And nearly all of what at one time was a very good
darkroom. Including a Bogan color enlarger for 35mm and 2 1/4 x 2 1/4
formats.

I've got one of the later Omega D-series enlargers, along with a
B-series (both accept the same lens boards and film holders). The
D-series has slots in the beam for three autofocus linear cams, and the
B-series has two. And the D series has the Chromega head for color
printing -- acquired just about the time I gave up on home darkroom
work. :-)

As Ive been a B&W buff..I do shoot a lot of "art:" stuff with the
cameras set for B&W or Sepia. Something possible to do with film..but
it was a royal pain in the ass if you only had one body on hand..and
had to swap a roll of color print film or Kodachrome (dating myself)
over to Tri-x or the new Tmax 400 after having shot half a roll and
needing to count the winds backwards..and occasionally getting screwed
up and doing a double exposure probably involving your best shot(s)
on the roll.

There is where the Zeiss Contax -- or the early Nikon cameras,
at least through the Nikon F -- win. Ever see a "Contax Cassette"? A
double shell cassette, one shell rotating inside the other to close to
form a light trap, or open to let the film pass out touching nothing, so
none of the scratches which the old felt on used cassettes gave after a
while.

Anyway -- the cameras listed could use *two* of those
cassettes, feed and takeup -- (both opened the slots as you locked the
back closed, and closed the slots as you opened the back. Anyway -- you
snapped off two blank exposures, opened the back and put the two
cassettes, joined by a short strip of film -- into a safe place, and
loaded the other film in with two more of the cassettes. Then when you
swapped back, you wound off two more blanks and you could continue to
shoot with no risk of mis-counting and double exposures. Yes, it cost
four exposures, and from a 12-exposure roll, that was a lot, but with
what I usually used (36+ exposures, hand loaded) it was not that much of
a bite.

I used the Contax cassettes first in a Contaflex Super (SLR with
only partially interchangeable lenses -- just the front element), and
missed that with all the shots I took over the years with a series of
Miranda cameras, starting with the Miranda F -- the closest to a Nikon F
in features that I could afford at the time. But that had a captive
takeup spool, so non Contax Cassettes for that. Later I got used Nikon F
bodies, and could start using them again.

[ ... ]

On the other hand...Plus-x would give me a 35mm print about 36x48"
with little loss in resolution and the negative stores nicely in a
glassine envelope (of which I have literally thousands filled with
negatives....6 to an envelope) and the various 4x5 negatives..done in
Plus-x..will give me a print big enough to cover a barn..with little
degredation of image quality.

I tended to use Tri-X -- processed in Acufine or Diafine, and
thus pushed to 800 ASA or 1200 ASA (The latter was really too low
contrast for me to be happy, so even in Diafine I would only go to 800
ASA after a few rolls.) (And of course, now 800 to 1200 ISO instead. At
least I never had to use DIN film ratings. :-)

My regular day to day cameras are Oly 3000s and 4000s and cost me
about $15 each on Ebay..some of which came still in the boxes as NOS.

I've got a Nikon D300s which I am quite happy with -- except
that I would like the ability to use the full frame instead of a 1.5 crop
factor, so the Fisheye and extra wide angle lenses looked normal -- but
I benefit in having my long lenses behave longer by a 1.5 factor too. :-)

Someday I might be in a position to pick up a digital SLR...but
frankly..I really dont "need" one as the above 2 cameras will go down
to 1.5" or so. The only issues..is not having a real wide wide angle
or a long telephoto.but for "snapshots" of a decent quality...they
work nicely. I seldom even take them off of Auto mode...they work very
well as is. In fact..I ran into a situation today..trying to take a
photo of the top of a sailboat mast some 32' up in the air for a
gentleman...the camera wouldnt focus properly..and when I put it into
manual focus..I couldnt remember HOW to manually focus. Chuckle. Had
to download the manual from the net and look it up

I've got a *lot* of lenses for the Nikon F -- only some of which
I can use on the D300s. I need to make a fixture so I can modify the
aperture ring on the older lenses to couple to the metering system in
the camera body.

Oh..other problem..no external flash sync. So I cant hook up some of
the BIG strobes that I have collecting dust unless I use some sort of
slave..and with a shutter speed of 1/2000th...the slave actuator has
to be damned quick

The D300s has a real flash connector, as well as the hot shoe to
talk to the newer flash units -- which themselves can talk to other
flashes too.

And while I have at least 30 or more 35mm camera lenses of all powers
from 18mm to 1200 mm (and converters for just about any lens
base....for SLR digital cameras..they are still pricey little *******s
and out of my price range. (Wish some of them would fit digital SLRs.)

Exactly. A number of my older lenses do have the modified
aperture rings, so I can use them in a somewhat less convenient metering
mode in the D300s, including the 500mm f8 mirror lens, but not
everything. At least a lot better than the D70, which would not talk to
lenses without a built-in chip for auto metering, thus sending me back
to a hand-held exposure meter. :-)

And if I manage to smash one (and I have) ...I simply pick up another
on Ebay for abut $21 shipping included.


But if anyone has a older surplus digital SLR with a normal range of
lenes they want to trade for something..Id be happy as hell to chat
about it.

None to trade, but one of my first Digital SLRs was a Nikon N90
which had been adapted by Kodak to digital for the AP people. Not a
particularly impressive number of pixels by today's standards, but when
I first started using that after working with one of the little Nikon
CoolPix P&S cameras, I remembered what I liked so much about SLRs vs
rangefinders and P&S cameras. One of the major things is just how slow
using the lens and display as a viewfinder made things, so you had to
play tricks to get short term (but predictable) events. :-)

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | (KV4PH) Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On 2014-09-23, Gunner Asch wrote:

[ ... ]

Or wood gas. You know..I do have a 300 amp Hobart with a 6 cylinder
Chrysler engine just collecting dust..right? Might make a great wood
gas welder.

Hmm ... 300 amp at what voltage -- and AC or DC? It it can
produce 240 VAC 60 Hz (with the usual center tap for 120 V operation as
well), that sounds interesting to me. :-)

If it is purely welding voltages -- no real need for that.

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | (KV4PH) Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On Tue, 23 Sep 2014 21:32:36 -0700, Larry Jaques
wrote:

On Tue, 23 Sep 2014 20:08:18 -0700, Gunner Asch
wrote:

On Tue, 23 Sep 2014 19:15:52 -0700, Larry Jaques
wrote:

On Tue, 23 Sep 2014 12:13:02 -0700, Gunner Asch
wrote:

On Tue, 23 Sep 2014 07:27:12 -0700, Larry Jaques
wrote:


Gonna take a pretty fair amount of power. Think about a genny that can
be run from a stream or steam.

I had it set all the way down on 1 to weld a 3/32" bracket. That
seems to be my^C^Cone weak point. Determining the welder power
setting. I'm now using much less power to weld and it's getting easier
each time. I really should practice more. sigh


Or wood gas. You know..I do have a 300 amp Hobart with a 6 cylinder
Chrysler engine just collecting dust..right? Might make a great wood
gas welder.

How do you get the 6 logs down into the cylinders to burn, mon?

Making wood gas sounds like a really toxic, smelly, and very messy
proposition.

REread my last sentence above, then read pg 58 (GOTO pg 73 via the
Wiki function), then tell me to make one anyway. I dare ya.

http://commons.wikimedia.org/wiki/Fi..._Emergency.pdf

What..the carbon monoxide poisoning bit if you put it into a closed
and sealed garage?

No, the daily/weekly/monthly cleaning, toxins, etc. It's a dirty and
time-consuming procedure. BTDT. Pass, for now, thanks.


Blink blink...you expected something different?

Run a Coleman lantern (white gas or propane) in the sealed cabin of a
boat and see if there are different results.

g


Yet I fail to see folks not using such lanterns (properly)

As for it being messy...of course it CAN be. Same with using a
fireplace. You ARE burning wood afterall.

Hate 'em. My fireplace is boarded over for several reasons. First is
that it's cracked, so flames might reach my attic. Second, I removed
and sold the insert (which they torched the beautiful 1/4" steel plate
heatilator to get it in the first place deep sigh). Third is that I
hate the smoke fires create into the house, even in well built stoves
and hearths. (Might as well be smoking again. No, thanks.) For all of
you who will say "My stove doesn't let any smoke into the house.",
I'll just file you with the folks who say "My dog doesn't bark." and
"Gun control works." gd&r

Yes, it's a viable way to produce gas for a vehicle. It's just not
one I wish to use for the time being. I reserve the right to change
my tune (in a hurry, if necessary) soon after the Fall.

Ah..Larry..no one suggested you convert all your vehicles to wood gas
now. But having the stuff on hand to do so might not be a bad
idea..or know where to swap/trade/steal it.

And knowing how to BUILD one will give you more trading stock after
the Fall..than just about anything I can think of, other than good
medical care. Btw...it generally only works easily/ well with L
head engines..so find a nice old inline 6 pickup truck somewhere and
put it up on blocks

Just a suggestion, not a command mind you.

Gunner

"At the core of liberalism is the spoiled child,
miserable, as all spoiled children are, unsatisfied,
demanding, ill-disciplined, despotic and useless.
Liberalism is a philosophy of sniveling brats."
PJ O'Rourke

On Tue, 23 Sep 2014 21:37:36 -0700, Larry Jaques
wrote:

On Tue, 23 Sep 2014 20:13:28 -0700, Gunner Asch
wrote:

On Tue, 23 Sep 2014 19:18:05 -0700, Larry Jaques
wrote:

On Tue, 23 Sep 2014 15:40:26 -0700, pyotr filipivich
wrote:

Larry Jaques on Tue, 23 Sep 2014
07:27:12 -0700 typed in rec.crafts.metalworking the following:

Or wood gas. You know..I do have a 300 amp Hobart with a 6 cylinder
Chrysler engine just collecting dust..right? Might make a great wood
gas welder.

How do you get the 6 logs down into the cylinders to burn, mon?

Making wood gas sounds like a really toxic, smelly, and very messy
proposition.

Naw. You bake the wood, catch the 'gas' which contains various
volatile compounds, which then gets used as a fuel gas. "Is simple" -
and a chance to use those might welding skills (obMetalworking)

Rightio!


And when the wood is done - you have charcoal to fire up the next
batch.

See my message to Gunner, page 58/9 for maintenance and hazards.
It'll be hard enough to stay clear of toxins after the Fall.
I don't need to bring them into my life on purpose, y'know?

So you will get plenty of exercise walking to town or afield and
towing a sled or wagon with your goods and cargo. Its good for you!

Afterall...if you manage to get a couple hundred pounds of canned
goods..you can make multiple trips.

And for that trip to the dispenary..after severing your finger with
a knife in the kitchen...not a problem.

Might be something of a problem after falling off the roof and
getting that pesky green stick fracture of your arm..but hey..walking
a number of miles in the cold with your humerus sticking out of your
sleeve side ways...not a big problem for a ecologically considerate
guy!

Hey, if you want dioxins and soot and nasty smell all over you, fine.
I guess that's not too far beyond being a ciggy smoker. g
just shakes head

Enjoy that long walk to the doctor with your 4 chickens to get that
arm taken care of. Or taken off.

Gunner

"At the core of liberalism is the spoiled child,
miserable, as all spoiled children are, unsatisfied,
demanding, ill-disciplined, despotic and useless.
Liberalism is a philosophy of sniveling brats."
PJ O'Rourke

On 24 Sep 2014 04:41:56 GMT, "DoN. Nichols"
wrote:

On 2014-09-23, Gunner Asch wrote:
On Mon, 22 Sep 2014 21:09:31 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Gunner Asch fired this volley in
:

[ ... ]

Ive still got a pair of Omega D2s if you want them. With the 4x5 and
35mm condensers. And nearly all of what at one time was a very good
darkroom. Including a Bogan color enlarger for 35mm and 2 1/4 x 2 1/4
formats.

I've got one of the later Omega D-series enlargers, along with a
B-series (both accept the same lens boards and film holders). The
D-series has slots in the beam for three autofocus linear cams, and the
B-series has two. And the D series has the Chromega head for color
printing -- acquired just about the time I gave up on home darkroom
work. :-)

As Ive been a B&W buff..I do shoot a lot of "art:" stuff with the
cameras set for B&W or Sepia. Something possible to do with film..but
it was a royal pain in the ass if you only had one body on hand..and
had to swap a roll of color print film or Kodachrome (dating myself)
over to Tri-x or the new Tmax 400 after having shot half a roll and
needing to count the winds backwards..and occasionally getting screwed
up and doing a double exposure probably involving your best shot(s)
on the roll.

There is where the Zeiss Contax -- or the early Nikon cameras,
at least through the Nikon F -- win. Ever see a "Contax Cassette"? A
double shell cassette, one shell rotating inside the other to close to
form a light trap, or open to let the film pass out touching nothing, so
none of the scratches which the old felt on used cassettes gave after a
while.

Anyway -- the cameras listed could use *two* of those
cassettes, feed and takeup -- (both opened the slots as you locked the
back closed, and closed the slots as you opened the back. Anyway -- you
snapped off two blank exposures, opened the back and put the two
cassettes, joined by a short strip of film -- into a safe place, and
loaded the other film in with two more of the cassettes. Then when you
swapped back, you wound off two more blanks and you could continue to
shoot with no risk of mis-counting and double exposures. Yes, it cost
four exposures, and from a 12-exposure roll, that was a lot, but with
what I usually used (36+ exposures, hand loaded) it was not that much of
a bite.


Ayup..I remember them!!

I used the Contax cassettes first in a Contaflex Super (SLR with
only partially interchangeable lenses -- just the front element), and
missed that with all the shots I took over the years with a series of
Miranda cameras, starting with the Miranda F -- the closest to a Nikon F
in features that I could afford at the time. But that had a captive
takeup spool, so non Contax Cassettes for that. Later I got used Nikon F
bodies, and could start using them again.

[ ... ]

On the other hand...Plus-x would give me a 35mm print about 36x48"
with little loss in resolution and the negative stores nicely in a
glassine envelope (of which I have literally thousands filled with
negatives....6 to an envelope) and the various 4x5 negatives..done in
Plus-x..will give me a print big enough to cover a barn..with little
degredation of image quality.

I tended to use Tri-X -- processed in Acufine or Diafine, and
thus pushed to 800 ASA or 1200 ASA (The latter was really too low
contrast for me to be happy, so even in Diafine I would only go to 800
ASA after a few rolls.) (And of course, now 800 to 1200 ISO instead. At
least I never had to use DIN film ratings. :-)

grin

My regular day to day cameras are Oly 3000s and 4000s and cost me
about $15 each on Ebay..some of which came still in the boxes as NOS.

I've got a Nikon D300s which I am quite happy with -- except
that I would like the ability to use the full frame instead of a 1.5 crop
factor, so the Fisheye and extra wide angle lenses looked normal -- but
I benefit in having my long lenses behave longer by a 1.5 factor too. :-)

Someday I might be in a position to pick up a digital SLR...but
frankly..I really dont "need" one as the above 2 cameras will go down
to 1.5" or so. The only issues..is not having a real wide wide angle
or a long telephoto.but for "snapshots" of a decent quality...they
work nicely. I seldom even take them off of Auto mode...they work very
well as is. In fact..I ran into a situation today..trying to take a
photo of the top of a sailboat mast some 32' up in the air for a
gentleman...the camera wouldnt focus properly..and when I put it into
manual focus..I couldnt remember HOW to manually focus. Chuckle. Had
to download the manual from the net and look it up

I've got a *lot* of lenses for the Nikon F -- only some of which
I can use on the D300s. I need to make a fixture so I can modify the
aperture ring on the older lenses to couple to the metering system in
the camera body.

You can buy em on Ebay and Burkes.

Oh..other problem..no external flash sync. So I cant hook up some of
the BIG strobes that I have collecting dust unless I use some sort of
slave..and with a shutter speed of 1/2000th...the slave actuator has
to be damned quick

The D300s has a real flash connector, as well as the hot shoe to
talk to the newer flash units -- which themselves can talk to other
flashes too.

And while I have at least 30 or more 35mm camera lenses of all powers
from 18mm to 1200 mm (and converters for just about any lens
base....for SLR digital cameras..they are still pricey little *******s
and out of my price range. (Wish some of them would fit digital SLRs.)

Exactly. A number of my older lenses do have the modified
aperture rings, so I can use them in a somewhat less convenient metering
mode in the D300s, including the 500mm f8 mirror lens, but not
everything. At least a lot better than the D70, which would not talk to
lenses without a built-in chip for auto metering, thus sending me back
to a hand-held exposure meter. :-)

Exposure meters I have up the ying yang. Except for a flash meter
which I loaned out and never saw again.


And if I manage to smash one (and I have) ...I simply pick up another
on Ebay for abut $21 shipping included.


But if anyone has a older surplus digital SLR with a normal range of
lenes they want to trade for something..Id be happy as hell to chat
about it.

None to trade, but one of my first Digital SLRs was a Nikon N90
which had been adapted by Kodak to digital for the AP people. Not a
particularly impressive number of pixels by today's standards, but when
I first started using that after working with one of the little Nikon
CoolPix P&S cameras, I remembered what I liked so much about SLRs vs
rangefinders and P&S cameras. One of the major things is just how slow
using the lens and display as a viewfinder made things, so you had to
play tricks to get short term (but predictable) events. :-)

Enjoy,
DoN.

"At the core of liberalism is the spoiled child,
miserable, as all spoiled children are, unsatisfied,
demanding, ill-disciplined, despotic and useless.
Liberalism is a philosophy of sniveling brats."
PJ O'Rourke

On 24 Sep 2014 04:46:30 GMT, "DoN. Nichols"
wrote:

On 2014-09-23, Gunner Asch wrote:

[ ... ]

Or wood gas. You know..I do have a 300 amp Hobart with a 6 cylinder
Chrysler engine just collecting dust..right? Might make a great wood
gas welder.

Hmm ... 300 amp at what voltage -- and AC or DC? It it can
produce 240 VAC 60 Hz (with the usual center tap for 120 V operation as
well), that sounds interesting to me. :-)

If it is purely welding voltages -- no real need for that.

Enjoy,
DoN.

Its 300 amps DC only unfortunately with 119 vts DC to run a
grinder...pure welding machine.

https://picasaweb.google.com/1040422...r?noredirect=1

Id swap it to someone just to clear out the back yard.

For a gas welder..I have a Ranger 9

Gunner

"At the core of liberalism is the spoiled child,
miserable, as all spoiled children are, unsatisfied,
demanding, ill-disciplined, despotic and useless.
Liberalism is a philosophy of sniveling brats."
PJ O'Rourke

On Tue, 23 Sep 2014 23:31:28 -0700, Gunner Asch
wrote:

On Tue, 23 Sep 2014 21:32:36 -0700, Larry Jaques
wrote:

On Tue, 23 Sep 2014 20:08:18 -0700, Gunner Asch
wrote:

On Tue, 23 Sep 2014 19:15:52 -0700, Larry Jaques
wrote:

On Tue, 23 Sep 2014 12:13:02 -0700, Gunner Asch
wrote:

On Tue, 23 Sep 2014 07:27:12 -0700, Larry Jaques
wrote:


Gonna take a pretty fair amount of power. Think about a genny that can
be run from a stream or steam.

I had it set all the way down on 1 to weld a 3/32" bracket. That
seems to be my^C^Cone weak point. Determining the welder power
setting. I'm now using much less power to weld and it's getting easier
each time. I really should practice more. sigh


Or wood gas. You know..I do have a 300 amp Hobart with a 6 cylinder
Chrysler engine just collecting dust..right? Might make a great wood
gas welder.

How do you get the 6 logs down into the cylinders to burn, mon?

Making wood gas sounds like a really toxic, smelly, and very messy
proposition.

REread my last sentence above, then read pg 58 (GOTO pg 73 via the
Wiki function), then tell me to make one anyway. I dare ya.

http://commons.wikimedia.org/wiki/Fi..._Emergency.pdf

What..the carbon monoxide poisoning bit if you put it into a closed
and sealed garage?

No, the daily/weekly/monthly cleaning, toxins, etc. It's a dirty and
time-consuming procedure. BTDT. Pass, for now, thanks.


Blink blink...you expected something different?

Run a Coleman lantern (white gas or propane) in the sealed cabin of a
boat and see if there are different results.

g


Yet I fail to see folks not using such lanterns (properly)

As for it being messy...of course it CAN be. Same with using a
fireplace. You ARE burning wood afterall.

Hate 'em. My fireplace is boarded over for several reasons. First is
that it's cracked, so flames might reach my attic. Second, I removed
and sold the insert (which they torched the beautiful 1/4" steel plate
heatilator to get it in the first place deep sigh). Third is that I
hate the smoke fires create into the house, even in well built stoves
and hearths. (Might as well be smoking again. No, thanks.) For all of
you who will say "My stove doesn't let any smoke into the house.",
I'll just file you with the folks who say "My dog doesn't bark." and
"Gun control works." gd&r

Yes, it's a viable way to produce gas for a vehicle. It's just not
one I wish to use for the time being. I reserve the right to change
my tune (in a hurry, if necessary) soon after the Fall.

Ah..Larry..no one suggested you convert all your vehicles to wood gas
now. But having the stuff on hand to do so might not be a bad
idea..or know where to swap/trade/steal it.

And knowing how to BUILD one will give you more trading stock after
the Fall..than just about anything I can think of, other than good
medical care. Btw...it generally only works easily/ well with L
head engines..so find a nice old inline 6 pickup truck somewhere and
put it up on blocks

Just a suggestion, not a command mind you.

I wish I had a bugout retreat way the fark out in nowhere, the time to
prep it, stock it, and secure it, and the money to do all the above.
If so, I might have one by now.

--
Give me the luxuries of life.
I can live without the necessities.
--anon

"Larry Jaques" wrote in message
...
On Tue, 23 Sep 2014 19:49:00 -0400, "Jim Wilkins"
wrote:


The bigger accuracy issue in building high-precision automated test
equipment, where I used the 0.01% resistors, was actually
capacitance.

When I was working QA at a manpack radio mfgr, we got a new HP LCR
meter. I was amazed at how much capacitance and/or inductance were
added to leads during tests just by getting near them or touching
them. I can't imagine designing a multilayer PCB, with all those
stray waves invading other spaces. Ditto ATE.

For a 6 layer board you put the power planes on layers 2 and 5 and set
the preferred directions on signal layers 3 and 4 at right angles to
each other, which is standard practice anyway to make autorouting
simpler. Then each trace has a constant capacitance to a power plane
and minimal coupling to the ones that cross it, and thus a uniform
characteristic impedance. If the logic family uses multiple voltages
like ECL you may have to go to 8 layers, but I could normally build a
densely packed, low-noise board with 6.

The solid planes need to be arranged symmetrically or the board will
warp since it's pressed together hot and the copper and glass-epoxy
shrink at different rates as it cools. I had to salvage a board
another tech designed with an outer ground plane on only one side
which had dished so much it would float.

When you see an unused area on a board that is crosshatched it's to
equalize the thermal contraction during manufacture.

If the power and ground planes are properly bypassed either can serve
about equally well as the "ground" plane, but you need to consider the
noise rejection margins both ways for asymmetrical logic families like
TTL. CMOS doesn't care. It's really necessary to distribute
low-impedance Tantalums around the board and have 0.1uF and 0.001uF
MLC caps at each device, since the two sizes have different frequency
responses in the GigaHertz range.

Thermal reliefs at the power plane vias make hand soldering and rework
far easier. They are the dashed rings at some pins on the Internal
Ground Layer:
http://www.4pcb.com/media/presentati...-build-pcb.pdf

If the impedance is critical such as in a microwave digital radio or
oscilloscope front end you may have to discuss the board's fabrication
with the vendor since they can't simultaneously control the thickness
of all internal layers and the overall board thickness. Something
needs to squish, like the prepreg between 3 and 4 if the outer layers
are controlled. It's a good idea to learn all the standard and
extra-cost limits of their processes.

I haven't heard of any other experienced circuit board designers who
thoroughly understood complex circuits. Management wasn't real happy
paying their lab manager to perform that apparently menial task, but I
proved I could deliver challenging boards that worked well the first
time.

While dual-slope A/D converters may automatically compensate for
temperature drift, the storage caps in the input Sample-and-Holds
don't. They matter because they are very small to track fast and the
FET that isolates the cap from the signal to maintain a steady
voltage
during the conversion also couples unwanted charge into the cap from
the voltage swing on its gate. We could couple a trimmed
compensating
charge switched by the gate control into the sample cap but the
tempcos weren't matched since the compensating cap was a small patch
on the circuit board.

Layered directly on the board, or soldered on?

They were small rectangles of copper on the board, capacitively
coupled to the ground plane. The trim was to bump them up part way
between power and ground with a hand-selected voltage divider, to
control the amount of charge they coupled into the cap. The S/H sample
cap was as small as acceptable to better follow rapidly changing input
signals.

This is what they are, if you're unfamiliar with measurement circuits:
http://en.wikipedia.org/wiki/Sample_and_hold
"If the input value was permitted to change during this comparison
process, the resulting conversion would be inaccurate and possibly
completely unrelated to the true input value."

The larger capacitance error source was dielectric absorption, when
a
polar capacitor dielectric acts slightly like a chemical battery and
takes a short while to fully charge or discharge after the voltage
changes. When you have only 5mS to set up and make a measurement it
becomes a serious concern.

I'll bet that was fun to figure out, even without the cycle-time
constraint.

The project engineer was a beard, ponytail, sandals and VW bus genius
Ph.D who had designed magical instruments at Keithley. He had me build
a current meter to characterize dielectric absorption currents which
could measure to a picoAmp in a milliSecond, which he said was state
of the art. Its output was a scope display of current vs time. I had
to heavily rigidize and shield it to eliminate mechanical vibration
from the ultrasonic building alarm and us talking. Even the less
sensitive (more stable) instruments in the production machine could
detect a person's electrical field at 10-20 feet if unshielded. I used
that to make it wake up and greet anyone who approached it after
hours, mostly the programmers. For some reason it ignored me sitting
still next to it, perhaps it accepted me as its master.

We had to have W.L.Gore make custom
Teflon-wrapped reed relays to cut the dielectric absorption in the
relay matrix that configures each test down so it didn't degrade
accuracy.

Teflon sheds electrons? Or is it just a good insulator? (Or are
those
the same question?

The molecular polar moment that gives a high dielectric constant
causes some delayed current flow as it physically relaxes after the
voltage changes. That's why electrolytics are poor for audio circuits.
Dielectrics with low absorption result in capacitors that are
physically large for their value, with unwanted parasitic effects.
They aren't the simple, perfect components that EEs learn them as in
school.

-jsw

On Wed, 24 Sep 2014 06:27:42 -0700, Larry Jaques
wrote:

On Tue, 23 Sep 2014 23:31:28 -0700, Gunner Asch
wrote:

On Tue, 23 Sep 2014 21:32:36 -0700, Larry Jaques
wrote:

On Tue, 23 Sep 2014 20:08:18 -0700, Gunner Asch
wrote:

On Tue, 23 Sep 2014 19:15:52 -0700, Larry Jaques
wrote:

On Tue, 23 Sep 2014 12:13:02 -0700, Gunner Asch
wrote:

On Tue, 23 Sep 2014 07:27:12 -0700, Larry Jaques
wrote:


Gonna take a pretty fair amount of power. Think about a genny that can
be run from a stream or steam.

I had it set all the way down on 1 to weld a 3/32" bracket. That
seems to be my^C^Cone weak point. Determining the welder power
setting. I'm now using much less power to weld and it's getting easier
each time. I really should practice more. sigh


Or wood gas. You know..I do have a 300 amp Hobart with a 6 cylinder
Chrysler engine just collecting dust..right? Might make a great wood
gas welder.

How do you get the 6 logs down into the cylinders to burn, mon?

Making wood gas sounds like a really toxic, smelly, and very messy
proposition.

REread my last sentence above, then read pg 58 (GOTO pg 73 via the
Wiki function), then tell me to make one anyway. I dare ya.

http://commons.wikimedia.org/wiki/Fi..._Emergency.pdf

What..the carbon monoxide poisoning bit if you put it into a closed
and sealed garage?

No, the daily/weekly/monthly cleaning, toxins, etc. It's a dirty and
time-consuming procedure. BTDT. Pass, for now, thanks.


Blink blink...you expected something different?

Run a Coleman lantern (white gas or propane) in the sealed cabin of a
boat and see if there are different results.

g


Yet I fail to see folks not using such lanterns (properly)

As for it being messy...of course it CAN be. Same with using a
fireplace. You ARE burning wood afterall.

Hate 'em. My fireplace is boarded over for several reasons. First is
that it's cracked, so flames might reach my attic. Second, I removed
and sold the insert (which they torched the beautiful 1/4" steel plate
heatilator to get it in the first place deep sigh). Third is that I
hate the smoke fires create into the house, even in well built stoves
and hearths. (Might as well be smoking again. No, thanks.) For all of
you who will say "My stove doesn't let any smoke into the house.",
I'll just file you with the folks who say "My dog doesn't bark." and
"Gun control works." gd&r

Yes, it's a viable way to produce gas for a vehicle. It's just not
one I wish to use for the time being. I reserve the right to change
my tune (in a hurry, if necessary) soon after the Fall.

Ah..Larry..no one suggested you convert all your vehicles to wood gas
now. But having the stuff on hand to do so might not be a bad
idea..or know where to swap/trade/steal it.

And knowing how to BUILD one will give you more trading stock after
the Fall..than just about anything I can think of, other than good
medical care. Btw...it generally only works easily/ well with L
head engines..so find a nice old inline 6 pickup truck somewhere and
put it up on blocks

Just a suggestion, not a command mind you.

I wish I had a bugout retreat way the fark out in nowhere, the time to
prep it, stock it, and secure it, and the money to do all the above.
If so, I might have one by now.

It really doesnt take much money. Seriously. It just takes a nose to
hunt down Stuff..and the time to deal with it. Money while
nice...shouldnt be an impediment so survival goods. I make very
little money these days..but just added my 6th sailboat to the corral.

Horse trading and the ability to scrounge. And making sure you dont
set up shop in a restrictive HOA or other restrictive area.


"At the core of liberalism is the spoiled child,
miserable, as all spoiled children are, unsatisfied,
demanding, ill-disciplined, despotic and useless.
Liberalism is a philosophy of sniveling brats."
PJ O'Rourke

Gunner Asch wrote:
On Tue, 23 Sep 2014 04:17:22 +0000 (UTC), Cydrome Leader
wrote:

Gunner Asch wrote:
On Mon, 22 Sep 2014 20:59:51 +0000 (UTC), Cydrome Leader
wrote:

pyotr filipivich wrote:
Gunner Asch on Mon, 22 Sep 2014 02:15:56 -0700
typed in rec.crafts.metalworking the following:
On Mon, 22 Sep 2014 07:11:25 +0000 (UTC), Cydrome Leader
wrote:

pyotr filipivich wrote:
Gunner Asch on Sun, 21 Sep 2014 19:12:04 -0700
typed in rec.crafts.metalworking the following:
On Mon, 22 Sep 2014 00:32:43 +0000 (UTC), Cydrome Leader
wrote:
I deviced to take apart an orignal Nikon F 35mm camera today, to see
what's inside.

About 5000 parts is the answer, for a completely mechanical 35mm camera.

WHY???!!! did you smash a Nikon F body???

They are still worth in excess of $200 each and for us
collectors..they are freaking priceless!!!

Barbarians - they break what they don't understand.

Tearing stuff apart is the greatest way to learn about how things work.

Disassembling is one thing. It is called "reverse engineering."
Breaking some thing because you don't understand how it works is not
"educational".

It's the fast way to see what's holding something together, and if you
don't need it put back, it's fine.

In fact, taking a hammer to saw to stuff is a good way to learn where the
strong and weak points are in something.


Its wanton vandalism of the worst sort. Try convincing yourself it is
something different...but it simply doesnt wash.

Ill bet you would love to smash open one of my Nikon S's.

I wouldn't mind.

Im sure you wouldnt.

Current value of the "black/black dial" one is $2500.00

That's about 33 times more than an F with no prism.

And I supplied you with a link to prisms on Ebay for $10

Must have missed it, but I've never seen an F prism that wasn't smashed go
for $10. If you come across a chromed one for a F that's not trashed or
been dropped, pick it up for $10 and I'll buy it for $25. The fact that
they did pop off and were so easy to break explains why they sell for more
than the bodies these days.

https://www.cameraquest.com/nrfs2bl.htm

Rare as hell

Complicated inside too!

Rangefinder mechanisms can be super complex, although it's not necessary
at all. Does the S have different sight lines and parallax correction?

Yes. Though the acessory finder..which is damned rare..would do all
that plus.

What would the "plus" features be?

Gunner Asch wrote:
On Mon, 22 Sep 2014 21:09:31 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Gunner Asch fired this volley in
m:

The Oly digitals have taken over most of the photo load of course..but
I simply have to get prints in my hands now and then...(Grin)

'had a whole -good- darkroom at one time. Simmon-Omega D2 enlarger with
the condensor color head, polycontrast filter set, the whole thing.

Gunner, stuff comes, and stuff goes. To be honest, a high-end pro-
digital can do anything and all things film could, except for
manipulation in the darkroom. And that was "once or nothing", at least
with the film, itself... like 'pushing' a roll, or cold-processing for
higher contrast. At least with digital, if you goof, you can try it
again. Screw up a roll of film, and you went out and shot it again.

Lloyd

Ive still got a pair of Omega D2s if you want them. With the 4x5 and
35mm condensers. And nearly all of what at one time was a very good

I may hit you up on this for the lamphouses. Just got some d6 (not sure if
they're first or second gen) columns with dichroic heads, but I want them
for B&W only. The fact that there are some many head options and
conversions is a testament to the "simple is best" design they used. No
other enlargers can be converted into so many things with so many options
and gadgets available from so many third parties.

On the other hand...Plus-x would give me a 35mm print about 36x48"
with little loss in resolution and the negative stores nicely in a
glassine envelope (of which I have literally thousands filled with
negatives....6 to an envelope) and the various 4x5 negatives..done in
Plus-x..will give me a print big enough to cover a barn..with little
degredation of image quality.

I sort of wonder where one would even get B&W paper larger than 20x24"
these days unless it's on a giant roll you ordered straight from the
factory. I've got a set of vacuum easels that need to be restored. Years
of tape and abuse have them in a rather non-flat state.

My regular day to day cameras are Oly 3000s and 4000s and cost me
about $15 each on Ebay..some of which came still in the boxes as NOS.

http://www.ebay.com/itm/Olympus-C-40...-/331323381208

http://www.ebay.com/itm/Olympus-CAME...-/121440644846

Someday I might be in a position to pick up a digital SLR...but
frankly..I really dont "need" one as the above 2 cameras will go down
to 1.5" or so. The only issues..is not having a real wide wide angle
or a long telephoto.but for "snapshots" of a decent quality...they
work nicely. I seldom even take them off of Auto mode...they work very
well as is. In fact..I ran into a situation today..trying to take a
photo of the top of a sailboat mast some 32' up in the air for a
gentleman...the camera wouldnt focus properly..and when I put it into
manual focus..I couldnt remember HOW to manually focus. Chuckle. Had
to download the manual from the net and look it up

Oh..other problem..no external flash sync. So I cant hook up some of
the BIG strobes that I have collecting dust unless I use some sort of
slave..and with a shutter speed of 1/2000th...the slave actuator has
to be damned quick

That reminds me I need to plug in and power up the Speedotron power pack
to keep the capacitors happy.

And while I have at least 30 or more 35mm camera lenses of all powers
from 18mm to 1200 mm (and converters for just about any lens
base....for SLR digital cameras..they are still pricey little *******s
and out of my price range. (Wish some of them would fit digital SLRs.)

it seems that if you get something like a 4/3 mount camera, you can get
adapters for most old lenses. The only adapter I bothered to but was a
Mamiya 645 to Nikon F mount device. There's really no point to it, but
yeah, it works if you do stop down metering of sorts.

And if I manage to smash one (and I have) ...I simply pick up another
on Ebay for abut $21 shipping included.


But if anyone has a older surplus digital SLR with a normal range of
lenes they want to trade for something..Id be happy as hell to chat
about it.

Gunner





"At the core of liberalism is the spoiled child,
miserable, as all spoiled children are, unsatisfied,
demanding, ill-disciplined, despotic and useless.
Liberalism is a philosophy of sniveling brats."
PJ O'Rourke

"Michael A. Terrell" on Tue, 23 Sep 2014
03:40:23 -0400 typed in rec.crafts.metalworking the following:

pyotr filipivich wrote:


You know when your design is complete - not when there is nothing
left to add, but when there is mottling left to take away.

OTOH, rarely are products "completed" so much as the designers
run out of time to make any improvements or changes.


AKA: Muntzed

Okay, I give - vvhat means "muntzed"?
--
pyotr filipivich
"With Age comes Wisdom. Although more often, Age travels alone."

"pyotr filipivich" wrote in message
...
"Michael A. Terrell" on Tue, 23 Sep
2014
03:40:23 -0400 typed in rec.crafts.metalworking the following:

pyotr filipivich wrote:


You know when your design is complete - not when there is
nothing
left to add, but when there is mottling left to take away.

OTOH, rarely are products "completed" so much as the designers
run out of time to make any improvements or changes.


AKA: Muntzed

Okay, I give - vvhat means "muntzed"?
--
pyotr filipivich

http://en.wikipedia.org/wiki/Madman_Muntz

"Jim Wilkins" on Wed, 24 Sep 2014 17:54:08
-0400 typed in rec.crafts.metalworking the following:
"pyotr filipivich" wrote:
"Michael A. Terrell" on Tue, 23 Sep
2014 03:40:23 -0400 typed in rec.crafts.metalworking the following:
pyotr filipivich wrote:
You know when your design is complete - not when there is
nothing left to add, but when there is mottling left to take away.
OTOH, rarely are products "completed" so much as the designers
run out of time to make any improvements or changes.
AKA: Muntzed

Okay, I give - vvhat means "muntzed"?

http://en.wikipedia.org/wiki/Madman_Muntz

Ah. Applying the "KISS" principle to manufacturing. "What
doesn't need to go in?"

--
pyotr filipivich
"With Age comes Wisdom. Although more often, Age travels alone."

On Monday, September 22, 2014 1:08:50 PM UTC-4, Lloyd E. Sponenburgh wrote:
"Jim Wilkins" fired this volley in news:lvpki2$j5c

:



That started in the 1980's with surface-mount electronics, which are

substantially more difficult to repair by hand than thru-hole, and not

reliable unless the tech who solders on the new parts is more than

usually skilled and experienced. I got the experience on lab

prototypes where a solder failure was only a brief inconvenience

instead of costing a field service call.



Jim, are you familiar with "Chip Quick" alloy?



It's a 'solder' with a large hysteresis between melting point and re-

solidification point. It allows you to 'dope' all the leads of an SMT

component, then simply run a hot iron 'round it once, and lift it off the

board as if it were not even soldered down.



Re-soldering is just as easy, as the stuff has amazingly high surface

tension (automatically centering the chip on the leads), and a very low

tendency to oxidize.



Lloyd

Chip Quick is indeed Good Stuff. I use it at least once a week. But I've never used it to solder chips in place. Is that even recommended? I'd worry about mechanical characteristics. Besides, it's pretty thick wire.

On 9/24/2014 1:39 AM, Gunner Asch wrote:
On 24 Sep 2014 04:46:30 GMT, "DoN. Nichols"
wrote:

On 2014-09-23, Gunner Asch wrote:

[ ... ]

Or wood gas. You know..I do have a 300 amp Hobart with a 6 cylinder
Chrysler engine just collecting dust..right? Might make a great wood
gas welder.

Hmm ... 300 amp at what voltage -- and AC or DC? It it can
produce 240 VAC 60 Hz (with the usual center tap for 120 V operation as
well), that sounds interesting to me. :-)

If it is purely welding voltages -- no real need for that.

Enjoy,
DoN.

Its 300 amps DC only unfortunately with 119 vts DC to run a
grinder...pure welding machine.

https://picasaweb.google.com/1040422...r?noredirect=1

Id swap it to someone just to clear out the back yard.

For a gas welder..I have a Ranger 9

Gunner

"At the core of liberalism is the spoiled child,
miserable, as all spoiled children are, unsatisfied,
demanding, ill-disciplined, despotic and useless.
Liberalism is a philosophy of sniveling brats."
PJ O'Rourke

Lots of lights and even other motors in the kitchen. 119 DC is good
stuff. Just don't expect to run fancy stuff that have electronics in it
unless they can handle or automatically convert the input to DC.

Martin

On 9/24/2014 10:45 AM, Cydrome Leader wrote:
Gunner Asch wrote:
On Tue, 23 Sep 2014 04:17:22 +0000 (UTC), Cydrome Leader
wrote:

Gunner Asch wrote:
On Mon, 22 Sep 2014 20:59:51 +0000 (UTC), Cydrome Leader
wrote:

pyotr filipivich wrote:
Gunner Asch on Mon, 22 Sep 2014 02:15:56 -0700
typed in rec.crafts.metalworking the following:
On Mon, 22 Sep 2014 07:11:25 +0000 (UTC), Cydrome Leader
wrote:

pyotr filipivich wrote:
Gunner Asch on Sun, 21 Sep 2014 19:12:04 -0700
typed in rec.crafts.metalworking the following:
On Mon, 22 Sep 2014 00:32:43 +0000 (UTC), Cydrome Leader
wrote:
I deviced to take apart an orignal Nikon F 35mm camera today, to see
what's inside.

About 5000 parts is the answer, for a completely mechanical 35mm camera.

WHY???!!! did you smash a Nikon F body???

They are still worth in excess of $200 each and for us
collectors..they are freaking priceless!!!

Barbarians - they break what they don't understand.

Tearing stuff apart is the greatest way to learn about how things work.

Disassembling is one thing. It is called "reverse engineering."
Breaking some thing because you don't understand how it works is not
"educational".

It's the fast way to see what's holding something together, and if you
don't need it put back, it's fine.

In fact, taking a hammer to saw to stuff is a good way to learn where the
strong and weak points are in something.


Its wanton vandalism of the worst sort. Try convincing yourself it is
something different...but it simply doesnt wash.

Ill bet you would love to smash open one of my Nikon S's.

I wouldn't mind.

Im sure you wouldnt.

Current value of the "black/black dial" one is $2500.00

That's about 33 times more than an F with no prism.

And I supplied you with a link to prisms on Ebay for $10

Must have missed it, but I've never seen an F prism that wasn't smashed go
for $10. If you come across a chromed one for a F that's not trashed or
been dropped, pick it up for $10 and I'll buy it for $25. The fact that
they did pop off and were so easy to break explains why they sell for more
than the bodies these days.

https://www.cameraquest.com/nrfs2bl.htm

Rare as hell

Complicated inside too!

Rangefinder mechanisms can be super complex, although it's not necessary
at all. Does the S have different sight lines and parallax correction?

Yes. Though the acessory finder..which is damned rare..would do all
that plus.

What would the "plus" features be?

I have a look down at it flip top that fits an F - a square line grid
to go with it - was for copy needs.

I see lots of Nikon gear for sale on ebay and even Amazon - going to
private camera stores.

Martin

On 9/24/2014 4:54 PM, Jim Wilkins wrote:
"pyotr filipivich" wrote in message
...
"Michael A. Terrell" on Tue, 23 Sep
2014
03:40:23 -0400 typed in rec.crafts.metalworking the following:

pyotr filipivich wrote:


You know when your design is complete - not when there is
nothing
left to add, but when there is mottling left to take away.

OTOH, rarely are products "completed" so much as the designers
run out of time to make any improvements or changes.


AKA: Muntzed

Okay, I give - vvhat means "muntzed"?
--
pyotr filipivich

http://en.wikipedia.org/wiki/Madman_Muntz



I used to have a cherry - beautiful - nice design... 4/8 track Muntz.
It must have been sold with the station wagon in 80.

Martin

On Wed, 24 Sep 2014 09:44:23 -0400, "Jim Wilkins"
wrote:

"Larry Jaques" wrote in message
.. .
On Tue, 23 Sep 2014 19:49:00 -0400, "Jim Wilkins"
wrote:


The bigger accuracy issue in building high-precision automated test
equipment, where I used the 0.01% resistors, was actually
capacitance.

When I was working QA at a manpack radio mfgr, we got a new HP LCR
meter. I was amazed at how much capacitance and/or inductance were
added to leads during tests just by getting near them or touching
them. I can't imagine designing a multilayer PCB, with all those
stray waves invading other spaces. Ditto ATE.

For a 6 layer board you put the power planes on layers 2 and 5 and set
the preferred directions on signal layers 3 and 4 at right angles to
each other, which is standard practice anyway to make autorouting
simpler. Then each trace has a constant capacitance to a power plane
and minimal coupling to the ones that cross it, and thus a uniform
characteristic impedance. If the logic family uses multiple voltages
like ECL you may have to go to 8 layers, but I could normally build a
densely packed, low-noise board with 6.

I can't imagine how difficult that was before the software design
packages became available.


The solid planes need to be arranged symmetrically or the board will
warp since it's pressed together hot and the copper and glass-epoxy
shrink at different rates as it cools. I had to salvage a board
another tech designed with an outer ground plane on only one side
which had dished so much it would float.

grunt


When you see an unused area on a board that is crosshatched it's to
equalize the thermal contraction during manufacture.

I'll no doubt look for that from now on.


If the power and ground planes are properly bypassed either can serve
about equally well as the "ground" plane, but you need to consider the
noise rejection margins both ways for asymmetrical logic families like
TTL. CMOS doesn't care. It's really necessary to distribute
low-impedance Tantalums around the board and have 0.1uF and 0.001uF
MLC caps at each device, since the two sizes have different frequency
responses in the GigaHertz range.

TTL? Old style. GHz fast TTL? Is that possible?


Thermal reliefs at the power plane vias make hand soldering and rework
far easier. They are the dashed rings at some pins on the Internal
Ground Layer:
http://www.4pcb.com/media/presentati...-build-pcb.pdf

Reliefs are neat for those of us who are semi-ham-handed.
(Act II popcorn PCB noted


If the impedance is critical such as in a microwave digital radio or
oscilloscope front end you may have to discuss the board's fabrication
with the vendor since they can't simultaneously control the thickness
of all internal layers and the overall board thickness. Something
needs to squish, like the prepreg between 3 and 4 if the outer layers
are controlled. It's a good idea to learn all the standard and
extra-cost limits of their processes.

I haven't heard of any other experienced circuit board designers who
thoroughly understood complex circuits. Management wasn't real happy
paying their lab manager to perform that apparently menial task, but I
proved I could deliver challenging boards that worked well the first
time.

And that's exactly what they wanted, I'm sure.


While dual-slope A/D converters may automatically compensate for
temperature drift, the storage caps in the input Sample-and-Holds
don't. They matter because they are very small to track fast and the
FET that isolates the cap from the signal to maintain a steady
voltage
during the conversion also couples unwanted charge into the cap from
the voltage swing on its gate. We could couple a trimmed
compensating
charge switched by the gate control into the sample cap but the
tempcos weren't matched since the compensating cap was a small patch
on the circuit board.

Layered directly on the board, or soldered on?

They were small rectangles of copper on the board, capacitively
coupled to the ground plane. The trim was to bump them up part way
between power and ground with a hand-selected voltage divider, to
control the amount of charge they coupled into the cap. The S/H sample
cap was as small as acceptable to better follow rapidly changing input
signals.

This is what they are, if you're unfamiliar with measurement circuits:
http://en.wikipedia.org/wiki/Sample_and_hold
"If the input value was permitted to change during this comparison
process, the resulting conversion would be inaccurate and possibly
completely unrelated to the true input value."

The larger capacitance error source was dielectric absorption, when
a
polar capacitor dielectric acts slightly like a chemical battery and
takes a short while to fully charge or discharge after the voltage
changes. When you have only 5mS to set up and make a measurement it
becomes a serious concern.

I'll bet that was fun to figure out, even without the cycle-time
constraint.

The project engineer was a beard, ponytail, sandals and VW bus genius
Ph.D who had designed magical instruments at Keithley. He had me build
a current meter to characterize dielectric absorption currents which
could measure to a picoAmp in a milliSecond, which he said was state
of the art. Its output was a scope display of current vs time. I had
to heavily rigidize and shield it to eliminate mechanical vibration
from the ultrasonic building alarm and us talking. Even the less
sensitive (more stable) instruments in the production machine could
detect a person's electrical field at 10-20 feet if unshielded. I used
that to make it wake up and greet anyone who approached it after
hours, mostly the programmers. For some reason it ignored me sitting
still next to it, perhaps it accepted me as its master.

Holy ****, Batman! Dat's hi-tech schtuff.


We had to have W.L.Gore make custom
Teflon-wrapped reed relays to cut the dielectric absorption in the
relay matrix that configures each test down so it didn't degrade
accuracy.

Teflon sheds electrons? Or is it just a good insulator? (Or are
those
the same question?

The molecular polar moment that gives a high dielectric constant
causes some delayed current flow as it physically relaxes after the
voltage changes. That's why electrolytics are poor for audio circuits.

That was a learning moment.


Dielectrics with low absorption result in capacitors that are
physically large for their value, with unwanted parasitic effects.
They aren't the simple, perfect components that EEs learn them as in
school.

The deeper you delve into most anything, the more that happens.
Constants aren't. Temperature, humidity, sound, & light can affect
lots of things in strange ways, as you just recalled.


--
Give me the luxuries of life.
I can live without the necessities.
--anon