I'm looking at -12.010VDC on a good DMM, and I just noticed on my Tektronix 2430A on 2V/div, it looks more like 11.75V, the trace is about 0.2-0.25V wide, that's normal, and it's not parallax. The trace is not as low as it should be to line up with the lines. However, using the math func. for voltage, it thinks it's about 11.96V The on-screen upper and lower voltage cursor's match with where GND is, and the CH1 trace. So both look noticeably off.
Yup just checked some other ranges, like on 500mV/div, placing the voltage cursor's across 6 blocks reads as 3.055, and the 3V from my PSU looks like it's 100-125m down below where it should be. And placing the voltage cursor there reads 2.960V
So what's that sound like this time ? And CH2 does exactly the same thing, same problem.
All the self-test's are still good. I don't use it a lot in a month, so IDK if it's been drifting for a while, but there's no doubt today.
Yup just checked some other ranges, like on 500mV/div, placing the voltage cursor's across 6 blocks reads as 3.055, and the 3V from my PSU looks like it's 100-125m down below where it should be. And placing the voltage cursor there reads 2.960V
So what's that sound like this time ? And CH2 does exactly the same thing, same problem.
All the self-test's are still good. I don't use it a lot in a month, so IDK if it's been drifting for a while, but there's no doubt today.