Beauty of old electrical and measuring things, etc.

[jim hardy]

The thing works very well so I'll be putting it to good use.

Don i just have to remark on the craftsmanship you demonstrate in your restorations of these beautiful old pieces.

C'est Beaux , mon ami !

old jim

 

[dlgoff]

I think that I have the same oscilloscope that's in the background.

And I have two of them.

 

[dlgoff]

Don i just have to remark on the craftsmanship you demonstrate in your restorations of these beautiful old pieces.

C'est Beaux , mon ami !

old jim

Thank you Jim.

 

[Charlie Cheap]

Before I went to Elkins Institute to become a TV service tech (TV repairman in my day) I used one of theses at the local 7-11 to keep our TV's working. They worked great...the tester and our TV. How times have changed!

 

[DrClaude]

An engineering marvel:

 

[OmCheeto]

An engineering marvel:

Looking at the 18½ minute run time for that video, I guessed that I wouldn't make it to the end.
I was wrong.

 

[dlgoff]

An engineering marvel:

Wow. What a cool engineering marvel. I want one.

Thanks for sharing @DrClaude.

 

[berkeman]

Wow. What a cool engineering marvel. I want one.

But only if you can restore it, right Don?

 

[dlgoff]

But only if you can restore it, right Don?

I'd make it look brand new.

 

[dlgoff]

Along with the B&K 550 tube tester, I was also give it's tube chart and it's B&K 610 expansion panel.

Here's a couple pictures of the expansion panel. IMO the 610's beauty comes from it's rotary switches.

Here's the tube tester with it's expansion panel & chart:

 

[jim hardy]

The silkscreenng looks pristine,

resistors are all oriented so color code reads L to R
service loops in all the wires

Somebody took pride in his workmanship.

What a find !

old jim

 

[berkeman]

resistors are all oriented so color code reads L to R

And I thought I was the only person who did that in my hand-built boards...

 

[dlgoff]

Somebody took pride in his workmanship.

And I thought I was the only person who did that in my hand-built boards...

That's because you all enjoy beauty too I think.

 

[davenn]

And I thought I was the only person who did that in my hand-built boards...

naaaa, all us good techies do that. It was ingrained into us not long after "Adam was a boy"

 

[dlgoff]

I've got my old vacuum system beauty,

all pumped down.

Now I'm going to try depositing a layer of gold one some round glass microscope slip covers (cleaned and coated with a thin layer of "clear" exposed photo-resist). I find that the photo-resist makes for a stronger metal bond. This same type of photo resist will then be used to etch a pattern on the gold layer. Here's a photograph showing the gold sample before it gets melted.

 

[dlgoff]

Here, the beauty is in "system's" reliability. After hundreds of pump-downs, never a component failure.

No matter how reliable rotary vacuum pumps are, they still need maintenance. One of my Edwards 8 dual stage pumps started to perform below expectations, so it's time for a clean and overhaul.

Here, the beauty is in the interior parts.

Oh BTW. Vacuum pump oil makes it a really messy job.

 

[DrClaude]

A restauration master at work

 

[dlgoff]

A restauration master at work

Just goes to show that restorations are no easy matter. Now you've got me wanting an old micrometer.

 

[davenn]

A restauration master at work

I kinda disagree with filing off of the casting ridges and filling on of hollows ( unless the hollows were caused by damage). Those ridges and hollows are part of the originality of its creation and now its uniqueness has been lost

Just goes to show that restorations are no easy matter.

yeah, it helps to have the right tools to do the job

 

[DrClaude]

I kinda disagree with filing off of the casting ridges and filling on of hollows ( unless the hollows were caused by damage). Those ridges and hollows are part of the originality of its creation and now its uniqueness has been lost

I agree. He does that in all similar restorations, but I think he should only repair damage.

yeah, it helps to have the right tools to do the job

And the talent!

 

[jim hardy]

Takes patience and manual dexterity.

My old friend Harry and a fiddle restoration in progress.
Note home made fiddle clamps - old sewing thread spools work well.

Difference between a fiddle and a violin ?
Violins don't get beer spilt on 'em.
(@dlgoff that's your Grandma's violin)

sorry ths one's off topic, being not electrical..

old jim

 

[dlgoff]

Takes patience and manual dexterity.

My old friend Harry and a fiddle restoration in progress.
Note home made fiddle clamps - old sewing thread spools work well.

View attachment 244989

Difference between a fiddle and a violin ?
Violins don't get beer spilt on 'em.
(@dlgoff that's your Grandma's violin)

sorry ths one's off topic, being not electrical..

old jim

Thanks for posting this photograph @jim hardy. I was going to post it here once I got your permission but just hadn't gotten around to asking you.

 

[davenn]

Difference between a fiddle and a violin ?
Violins don't get beer spilt on 'em.

hahaha

 

[dlgoff]

My old friend Harry and a fiddle restoration in progress.

Harry did a great job putting this violin back together after all the abuse I gave it as a kid.

sorry ths one's off topic, being not electrical.

But the waveforms a violin produces is just as complicated as electrical analog signals. Years ago, after my school's EE department invited Robert Moog to explain the electronics of the music synthesizer he designed and built, I played around making analog circuits that "duplicated" string instruments. IIRC a violin's waveforms are rich in odd harmonics.
Anyway, here's that old violin now.

 

[jim hardy]

IIRC a violin's waveforms are rich in odd harmonics.

They're interesting also from a mechanical perspective.
The front and back vibrate in various modes, not just as a simple sheet
a wood soundpost about the diameter of a pencil is placed right underneath the 'bridge' to mechanically couple couple them,
and a 'bass bar' stiffens the front to help it produce low notes,
as you can imagine the varying thickness of those front and back plates controls the sound of the fiddle.
Yours was well made. The neck mount was unusual, similar to that of a region in the way northeast of Germany. Harry liked its tone and said whoever thinned its front and back knew what he was doing..

Theory of vibrating plates is an interesting niche

History of Chladni's Law
f ~ (m+2n)^2
The story behind the equation:
Ernest Florens Friedrich Chladni of Saxony is often respectfully referred to as "the Father of Acoustics". Indeed, his body of work on the vibration of plates has served as the foundation of many experiments by countless other scientists, including Faraday, Strehlke, Savart, Young, and especially Mary Desiree Waller. Chladni's study consisted of vibrating a fixed, circular plate with a violin bow and then sprinkling fine sand across it to show the various nodal lines and patterns. The experiment is particularly rewarding in that high frequencies often exhibit strikingly complex patterns (see the pictures on the image page). In fact, Chladni's demonstrations in many royal academies and scientific institutions frequently drew large crowds who were duly impressed with the aesthetically sophisticated qualities of vibrating plates. Napoleon himself was so pleased with Chladni's work that he commissioned the further study of the mathematical principles of vibrating plates which then spurred a plethora of research in waves and acoustics. While experimental methods and equipment have been much improved in the last 200 years, Chladni's law and original patterns are still regularly employed to study plate vibrations.
References:
Rossing, Thomas D. "Chladni's Law for Vibrating Plates." American Journal of Physics.Vol 50. no 3. March, 1982.

see also
http://newt.phys.unsw.edu.au/jw/violintro.htmlhttp://newt.phys.unsw.edu.au/jw/chladni.html
I hope your grandchildren enjoy it as much as you did..

 

[dlgoff]

They're interesting also from a mechanical perspective.
The front and back vibrate in various modes, not just as a simple sheet
a wood soundpost about the diameter of a pencil is placed right underneath the 'bridge' to mechanically couple couple them,
and a 'bass bar' stiffens the front to help it produce low notes,
as you can imagine the varying thickness of those front and back plates controls the sound of the fiddle.
Yours was well made. The neck mount was unusual, similar to that of a region in the way northeast of Germany. Harry liked its tone and said whoever thinned its front and back knew what he was doing..

Theory of vibrating plates is an interesting nichesee also
http://newt.phys.unsw.edu.au/jw/violintro.htmlhttp://newt.phys.unsw.edu.au/jw/chladni.html
I hope your grandchildren enjoy it as much as you did..

Thanks for these references Jim. And thank Harry for his expert restoration.
I hope this fiddle will be passed down for generations.

 

[davenn]

Hi Don,

Had to show you this old bit of gear I found in a historical society museum in the city of Bathurst, NSW Australia.
Wife and I had a long weekend holiday there a couple of weekend's ago

Dating from the early 1900's, an X-ray "machine"

No shielding or anything, just "spray and pray" hahahaDave

 

[dlgoff]

Hi Don,

Had to show you this old bit of gear I found in a historical society museum in the city of Bathurst, NSW Australia.
Wife and I had a long weekend holiday there a couple of weekend's ago

Dating from the early 1900's, an X-ray "machine"

View attachment 245251

View attachment 245252

No shielding or anything, just "spray and pray" hahahaDave

That is so awesome @davenn. I'd love to be "spraying" some X-rays with it. Would go good with my other "spray" machine.

 

[Mark44]

sorry ths one's off topic, being not electrical..

Just put a pickup in it, making it an electric violin.

 

[dlgoff]

Just put a pickup in it, making it an electric violin.

Just like my old friend Robby Steinhardt did.