Burster 1423 decade resistor

[doktor pyta]

Why my new Burster 1423 opt GPIB is so heavy?
I asked myself this question while carrying it to the lab.
The answer is on the pictures below.
Six powerful servomotors inside.

[Huluvu]

Yes I was wondering too why this device is soo heavy (I have the same) 

[HighVoltage]

How interesting!

Do you have a service manual for this decade?
How accurate is it still ?

[doktor pyta]

I don't have service manual.
Only operation manual (attached below).
At least I'm able to set values using GPIB.
It is very loud while changing positions.

My unit is made in 1995.
Resistance values are within specs, typically within half of specified tolerance.

Best Regards

[HighVoltage]

Nice, thanks for the manual

I expected this decade to be in specs, even after so many years.
The resistor material on this 1423 is Zeranin and Burster used it in those days for their high end resistors.
They stopped using Zeranin after it became unobtanium.
Their 1284 series fixed resistors were also made out of Zeranin.

[Gyro]

It looks like pretty much the ideal resistive material. Low TC, low thermal EMF against copper and soft solderable.

https://www.isabellenhuette.de/en/precision-alloys/products/zeraninr/