Editing DECsystem-10 Power Supply Guide (section)

== Setting the voltages ==
DEC's MH10 procedure, with power on:<ref name="mh5" />
# Find the regulators and backplane power tabs on the power wiring diagram D-IC-MH10-0-PW.
# Set +5 V at the backplane tabs with the potentiometer on top of each H744.
# Set +20 V with R17 on the side of each H754.
# Set −5 V with R21 on the top of each H754.
# Repeat the last two steps until neither needs further adjustment.
All three must be within ±5% at the backplane, and DEC asks for adjustments to be made at 20–30 °C ambient.<ref name="mh5" /> R17 sets the full 25 V span between +20 V and −5 V and R21 then sets −5 V to ground, which is why the two interact. For the H754 on its own, DEC's method is to power down, disconnect the load, power up, set 25 V across the outputs with R17 and −5 V to ground with R21, then reconnect the load and check again.<ref name="mh4" />