HP 59303A

The Hewlett-Packard 59303A is a HP-IB digital to analog converter.

It can output from -9.99V to +9.99V with 0.1% full-scale accuracy (±10mV). The output can sink or source 10mA.

Output adjustment/calibration ↵^

The only adjustments in the 59303A are for the positive and negative amplifiers on the DAC board (A3). To adjust them, follow these instructions (copied from the service manual):

Apply power to the 59303A and connect its output to a multimeter with better than 0.1% accuracy. Remove the top cover of the 59303A.
On the front panel set the OUTPUT MODE switch to 0.00V REF.
On switch S1 of the A2 board press switches 1, 2, 3, and 4 to the OFF position.
Set switch 3 to ON and adjust variable resistor R42 (+ zero adjust) for an indication of +0.00V on the multimeter.
Set switch 4 to ON and adjust variable resistor R40 (- zero adjust) for an indication of -0.00 ± .01V.
Set switches 1 and 2 to ON and adjust variable resistor R45 (- full scale adjust) for an indication of -9.99V ± .01V.
Set switch 4 to OFF and adjust variable resistor R46 (+ full scale adjust) for an indication of +9.99 ± .01V.
Repeat steps 3 to 7 until further adjustment is not required.
Set switches 1, 2, 3, and 4 to the OFF position for normal operation.