Old fashioned 2 pole ac/dc motor/generator used for classroom demonstrations
Are any of the three copper bands around the rotor axle a commutator rather than a slip ring? If so, you can get DC out with DC on the field coil. Don't overheat the field coil with too much current. It should never be too hot to touch. Measure the resistance of the field coil, and keep the applied voltage below that number, so A<= 1 amp.