Siemens resistor decade, Oldie Restoration.

[Martin.M]

Siemens Oldie:  R Decade 0 to 111,111 Ohm, wired with Manganin ( Isabellenhütte )

[Martin.M]

here is the picture from the problem inside.



tested with a needle. Begin of the cable = Mp0

Mp0 to Mp1: closed
Mp0 to Mp2: open

[NWerner]

I have a siemens&halske unit which uses same switch technology. Resistors look similar as well.

In my unit manganin wire was connected to copper wire (at least for thinner wire) for easier interconnections.
This manganin-copper connection is probably a weak spot.

[Martin.M]

the green color between the both test point is oxidation ( Grünspan ).

Manganin is a copper mixed with around 15 per cent mangan, so easy to solding.
Not the same then the tungsten mixed wires for heaters, they are horrible in connecting.

If you have a repair, I have a NOS roll Isabellenhütte Manganin 69,7 Ohms/m, made 1985 = aged.

[Vgkid]

That is a nice decade, shame about the resistor. Thankfully manganin is solderable, so you can solder the two halves together.

[Gyro]

It's nice to see Vaseline being specified as a contact lubricant for sliding contacts in decade boxes. I've always found it really good but it's good to see a manufacturer recommendation.

[Martin.M]

fascinating:
the oldie is using abs. ohms instead of intern. ohms 

[Neepa]

It's nice to see Vaseline being specified as a contact lubricant for sliding contacts in decade boxes. I've always found it really good but it's good to see a manufacturer recommendation.

No chance of those switch contacts tarnishing even if it's the 9th millenium and the 186th service cycle for the box.