JYE Tech Forum

I just completed building a DSO128 a few weeks ago and I find the zero point drifts while in use. Is this normal behavior for this device?

I haven't seen my DSO138 drift in normal use.
The zero reference does move when the battery is to low to properly generate the minus voltage supply.

Is your DC power supply voltage greater than 8 volts? If not, the trace may drift down as the power supply voltage drops. For my DSO138, the DC voltage needs to be greater than 7.8 volts. I run it off an 8.4v NiCd battery.