Pye
Mk4 PSU (power supply unit) front view
The Pye PSU with the single control, the meter selection switch. The switch and the meter are colour coded and the meter reading should fall in the appropriate coloured zone.
The on/off
switch was on the CCU.
This Pye PSU type 842396BX,
serial number 50 is awaiting restoration. I have dated it to late 1959.
This design of voltmeter first appears on the Mk4 PSU, it was used unchanged
on later camera designs for at least a decade!