you've got that part wired right, A to A [armature], F to F [field] - if different generators and different regulators result in the identical behavior, what's left? wiring someplace is wrong, check the ammeter wires again
"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir "When we tug a single thing on an old truck, we find it falls off" ~ me Some TF series details & TF heater pics