The output level on my BK Precision 4017A function generator is drifting.
For example, if I set the output level to 10.0V on a 2kHz sine wave, driving a variety of simple half-wave rectifier and diode clamp circuits, the function generator output level will hold fairly steady for perhaps 10 or 15 minutes then drift down to around 6 volts or up to around 15 volts over a period of a couple of minutes, then settle at the new level for a while.
Any suggestions what might be wrong please e.g. dodgy potentiometer, capacitor, or transistor, or are there just too many possibilities to diagnose? I have read the manuals, Googled FG trouble shooting (a lot on frequencies but nothing so far on output level) and emailed BK Precision support but no reply and I guess they are closed now for the weekend.