Hickok 1605M voltmeter

[TimFox]

While I wait for the manual that I ordered on eBay, can anyone tell me the function of each of the six calibration pots facing up on the top board?  I have the version using an AD 545 op amp, not the older version with photo chopper.

[coromonadalix]

I would say take their values  before adjusting them,   and maybe by trial and errors you could find their use ??

[TimFox]

I now have the manual.  In case someone finds this on search, here is the layout of the calibration pots on the top board, seen from above.  Each sets the full-scale value.  Hickok recommends adjusting at 80% of F.S., and using 400 Hz for AC voltage calibration.

         REAR

                    R48 [50 mA DC]

R47
[0.05 V DC]

                    R37
                    [0.5 V AC]

R39 
[1.5 V AC]

                    R41
                    [5 V AC]

R44 
[50 V AC]

            FRONT