I used a 12 AWG wire formed into a U shape for the short and the zero voltage measured less than 0.2 uV after a good 2+ hour warmup. However, I am seeing drifts of several uV for the 752 calibration. I was using TV twin lead to connect the 732 to 752 and 752 to 3458A since that's really all I have for now. I suspect thermals are killing me so I need to find some low thermal shielded differential cable to connect from the 752 to the 3458A. I did not see anything like that in Pomona's arsenal. I was thinking about Bill Gold's idea of making my own but I think it would end up being \very stiff. Any other ideas for a good source of shielded copper wire twinax?
Randy AE6YG On Mon, Jul 27, 2015 at 4:10 PM, J M via volt-nuts <volt-nuts@febo.com> wrote: > I use a 8 oz styrofoam cup to isolate air currents around the 3458A > terminals when zeroing with shorting bar > > > Sent from my 20" Texas sized > iPhone.... > > > > On Jul 27, 2015, at 2:57 PM, Richard Moore <richiem5...@gmail.com> > wrote: > > > > > > Randy — My 3458A manual specs 12 or 14 gauge solid copper wire for the > short, bunt in to a U shape. I use 14 gauge. Poul-Henning’s comments about > thermals are well-taken — even a simple folded up carboard shield helps. > But I think you’re near the limit. > > _______________________________________________ > > volt-nuts mailing list -- volt-nuts@febo.com > > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > > and follow the instructions there. > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. > _______________________________________________ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
