I just traded for a 510A AC reference. It puts out 10 VAC. This one is marked 1000 Hz. Being cautious with such an old piece of gear, I brought it up slowly on a variac, so as not to blow the filter caps.
Still not having sent off anything for calibration, I attached a 5.5 digit DMM to the 510A and it reads 09.9945. The DMM hasn't been calibrated in many years and I'm sure that the 510A hasn't been calibrated in at least 10 or more years (most likely many more, considering where it came from). I'll probably send the HP 3478A off for calibration after I get paid next week. Being 6.5 digit and freshly calibrated, it will be interesting to see how it reads the 510A. Joe Gray W5JG _______________________________________________ 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.