So, all assembled and working, but I can’t get the DC Gain calibrated. With 1.5V DC input, I can’t rotate RV1 far enough to calibrate.
DC Mean values with a 1.47V input and RV1 turned fully clockwise:
On 0.1V range = 400mV ??
On 0.2V range = 800mV
On 0.5V range = 0.95V
On 1V range = 1.59V
On 2V range = 1.44V
On 5V range = 2.5V
And with RV1 centred:
On 0.1V range = 400mV ??
On 0.2V range = 738mV
On 0.5V range = 0.72V
On 1V range = 1.09V
On 2V range = 0.63V
On 5V range = 0.5V
Calibration results:
CH1 offset at 5V/div : 138 OK
CH1 offset at 1V/div : -2 OK
CH1 Y-position low 32
CH1 Y-position mid 128
CH1 Y-position high 223
Any ideas what I’ve done wrong.