A bleeder resistor can usually be selected to prevent the screen voltage from getting out of control.

Arcs can also be initiated by any loose material inside the tube, or by excess screen voltage.

In general, if the anode voltage exceeds the screen voltage, this region is avoided, and good performance can be expected.

Since secondary electrons can outnumber the primary electrons, in the worst case, particularly as the plate voltage dips below the screen voltage, the plate current can decrease with increasing plate voltage.