EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: devinw on November 08, 2024, 04:50:20 pm
-
Like the title says, when I power the unit up, the bias voltages on the channels is always different, especially channel 2. 2 has been anywhere from 100 to 250mV, and yesterday it was 800mV! I realize this is not a DMM, but 800mV seems simply outrageous for any oscilloscope. I realize I can enter in a bias voltage for each channel, but that doesn't help if it boots up to a different bias each time. Is there some internal cal it runs when starting up that is screwy?
Anyone else experience this? Or should I send this thing back?
-
Have you run the calibration?
-
Have you run the calibration?
I just tried the self cal. After the cal, all channels were looking good with low offset. We'll see how it is on the next bootup.
-
I've had the unit powered on for a few minutes and CH1 is averaging about 4mV bias, and CH2 is 60mV. The 60mV one was under 1mV yesterday after self-cal and using it for a few hours. I think I'm sending this thing back unfortunately.
-
You have to let it warm up, but... 60mV sounds like a lot to me after "a few minutes".
Does it go away with time?
-
At what input sensitivity settings are you observing the offsets?
-
At what input sensitivity settings are you observing the offsets?
Good point! I assumed this was at high sensitivity but every time I assume I make an ass of myself.
60mV at 10v/div would be perfectly normal.
(https://www.eevblog.com/forum/testgear/rigol-dho0804-starts-up-with-large-varying-offset-(bias)-voltages/?action=dlattach;attach=2431089;image)