With the locomotive stationary, the main generator (MG) output is connected to the grids instead of the traction motors.
At standstill, main generator output is initially low voltage/high current, often in excess of 1000 amperes per motor at full power.
The generator outputs were fed through a good quality ammeter and into a 40 amp/hr 12V lead/acid battery which was half to three-quarters charged.
This switch will then close, resulting in a cascade down the generator that produces nV at the generator output (again, only in the ideal case).
From shortfalls in generator output, these units are built with binary drive systems combining hydraulic mechanical systems with Muscle Packages.
These systems interrogate the impedance of a split or dual-pad return electrode and will alarm out, disabling further generator output in case of fault.
The second choice was much more attractive from a personal standpoint: rupturing the regulator globe would release all the generator's output directly into the chamber.
We now know 32 consecutive bits of the generator output.
Note from the table above that agrees with the generator output 4 times out of 8 - a 50% correlation.
However, specific individual incorrect keys may well generate LFSR output which agrees with the generator output more or less often than exactly 50% of the time.