Knick S12 saved from destruction

[Kjelt]

So again by visiting the metal scrapyard I could save an "antique" electronic device from destruction.
This time it is a Knick S12 millivolt precision power supply.

After a fast clean of the exterior I noticed the whole casing except for the front plate is one piece of metal.
Nice quality.

[Kjelt]

Opening it up on the backside of the front plate there is this large multiturn potmeter which looks way more impressive than todays blue/black Bourns multiturns.
The selector switch with the adjustable resistors mounted around them looks still shiny as if it was made last week. 

At the back of the inside to the left is a small transformer a large precision resistor of 1kohm and a aluminium box with the powersupply in it (probably).
I haven't took it out and opened it (yet).

[Kjelt]

To the side of this aluminium box there are two cards with the quality control paperwork.
They reveal the date of manufacture: january/february of 1970.
WOW almost 50 years old.

Would it still work ?
Only one way to find out: power it up.

Yes....... 50 years old and still running, amazing...... 

[shakalnokturn]

It seems to reveal that your fluke is slightly out of cal. though 

[Kjelt]

  I already purposely did not post in the nanovoltnuts board 

[Vgkid]

Thanks for the teardown. Wouldn't surprise me if they used cd solder for the lower ranges.
What is the lowest range for the unit?
Here is my nv source.
https://www.eevblog.com/forum/metrology/keithley-260-teardown/

[Kjelt]

What is the lowest range for the unit?

Lowest scale is 0,05 (range: 0-500uV) , highest scale is 1000 (range: 0-10V)

Here is my nv source.
https://www.eevblog.com/forum/metrology/keithley-260-teardown/

Looks very nice 

[Kjelt]

And set 1V on the 1000 scale on an uncalibrated Keithly 2000 and with the scale dial just turning it down one scale at a time till 0 (last picture).
For the very attentioned people I made an error with the 0,5V picture so had to redo that one.

[guenthert]

What is the lowest range for the unit?

Lowest scale is 0,05 (range: 0-500uV) , highest scale is 1000 (range: 0-10V)
[..]

That's an astonishing wide range.  Good find!