Mercury-vapour rectifier: voltage drop is approximately 15V and remains nearly constant regardless of load current.
CRITICAL: Mercury-vapour tubes require a minimum warm-up period of 30-60 seconds before applying B+ voltage. Applying plate voltage to a cold mercury-vapour rectifier causes cathode stripping and rapid tube failure.
Mercury temperature operating range: 24-60 degrees C. Below this range, mercury condensation can cause arc-back.
Rectifier reference confirms: Vdrop=15V, max DC output=115 mA, max AC voltage=450V RMS per plate.