> To everybode who answered: Thanks, so it was not only me not finding > the leftovers of delimiters. Still curious why they made it that way. > No reason to replace! > > Dave: I am aware of the resistor wire alloys like Konstantan, > Manganin, Isabellin, Evanohm and their variants. What I didnt > understand yet is the wiring between the resistors and the decades > and so on - its just not simple silver-coated or tinned cooper wire, > it more looks like a resistive wire - big and massive, bad to solder. > > Bill: Do I understand right, they use the inter-resistor wiring to for > compensation ? (Your mail worked fine) > > Sounds like a "bigger but reproducable resistance than wildly drifting > cooper wire" scheme to me. I try to figure out. > > The repair itself worked out very nice, the workplace 34401A in > dcv:dcv ratio mode was happy with the results. > > BR > > Hendrik Hendrik, I didn't catch that you were asking about the interconnecting wiring. That is likely to be the same material as used to make the resistors (Manganin). That would maintain the low tempco of the total unit, and avoid the comparatively large resistance drifts of copper wire. Manganin is hard to solder without a flux that can remove the surface oxide that forms on manganin wire. Flux used for soldering stainless steel might be a good one to try. Just be sure to clean the joints very well after using it. The old ESI standards are very nice instruments to have. I have an old ESI decade capacitance box built like the Dekavider and Dekapot units. It's quite accurate; good enough to allow me to evaluate RCL-type multimeters. Cheers, Dave M

> Hendrik, > I didn't catch that you were asking about the interconnecting wiring. > That is likely to be the same material as used to make the resistors > (Manganin). Sounds plausible. > That would maintain the low tempco of the total unit, and avoid the > comparatively large resistance drifts of copper wire. As I wrote in my "If I understand right" message." > Manganin is hard to solder without a flux that can remove the surface > oxide that forms on manganin wire. Flux used for soldering stainless > steel might be a good one to try. Just be sure to clean the joints > very well after using it. > Fortunately the previous owner kept the material when he modified it. > The old ESI standards are very nice instruments to have. I have an > old ESI decade capacitance box built like the Dekavider and Dekapot > units. It's quite accurate; good enough to allow me to evaluate > RCL-type multimeters. > Besides that Dekavider which was part of a power supply i have a also recently ebayed SR1010 that was the cheapest to get and needed some TLC but the 34401A at work is not really a good instrument to check it, and i have my "noble thing" a Dekavider RV722 which I use quite frequently for ratio measurements, simply considering it ok for me as i was not yet able to show any problems with it (HP3456A and 34401A in ratio mode are both happy.) > Cheers, > Dave M > Cheers Hendrik