Adjusting analog gain in DSO 068

[shop]

Hi everyone. I want to know how to adjust analog gain in my DSO because measured voltage is bit too high on any multiplier. Best regards.

[jye1]

Many resistors involve to determine the analog gain. Can you describe the reading error with more details? That might help to identify its causes.

[shop]

Here is another topic where i describe e my issue s:https://www.jyetech.com/forum/viewtopic.php?f=16&t=1540

[shop]

Is there any solution to my problem? I think that is unacceptable to get over 10% error readings of voltage.
Signal level 5vpp @ 1kHZ
1V x1 - 5,57V
1V x2 -5,60V
1V x5 - 5,67V
Signal level 3vpp @ 1kHZ
1V x5 - 3,33V approx.
1V x1 - 3,33V
0,1v x5 -2,95V
Signal level 1vpp @ 1kHZ
0,1V x2 - 1,10V
0,1 V x5 -1,08V
Signal level 0,3vpp @1kHZ
0,01v x5 - 0,315V
0,1V x2 - 0,31V

[shop]

So I must assume that there's no way to adjust/calibrate this thing?

[jye1]

Some resistors might be off their labelled value for too much. You can try changing R11. Make it in series with a 20 ohm resistor, for example.

[shop]

I changed r11 resistor to adjustable one (0-1000 ohm) and adjusted it until I get satisfaction results. And now is way better than before. Error at range 0,1 and 1 is neglible. But 10mV range is now off by about 6mV(more than half div). And I can live with it but maybe there is a way to calibrate only this range. Thanks for help

[shop]

So I must assume that there's no way to calibrate only 10mv per div?