Howdy all.
Was trying to calibrate a DM501A this weekend. DC volts calibrated with no issues however AC volts and dBmV did not.
In both cases I ran out of pot room just a tad before I had it in agreement with my Fluke 289 meter that I used for reference.
I'm debating if I should just not worry about it. It is such an old meter.
Any idea what is the normal reason they don't reach calibration range? I used a 500Hz signal to calibrate but I saw no difference at 100Hz or 1KHz so I don't think the issue is around there.
I'm wondering how deep I'll have to go to fix this one. It looks like dBmV doesn't have enough resolution to be useful so I'm not so worried about that.
