Siemens Sf P 6.11s Projektor 2000 16mm Film Projector - Collectible
Here are comments from our tech:
The 50 Hz on the sign is to indicate that it is for AC, not DC, and for at least 50 Hz. Long ago some nations in Europe had as low line frequencies as 40 or 37 Hz.
Running it on 60 Hz does not matter, the speed will be the same. It is powered by a series motor.
The sound is optical. There is a small lamp, the filament of which is projected on the edge of the film. The transmitted light goes to a
photocell and then to a solid state amplifier. It works very well.
The 2000 W on the label is not true for 120 V operation (that it is
readied for). A 1 kW resistance near the lamp-housing is no longer needed
so it is bypassed. Remains 1 kW for the lamp. So, the projector needs 120 V
lamps in the future. They do not need to be as strong as 1 kW!
Two lenses, a 35 and a 50 mm, come with the projector. They are both German
lenses, of excellent quality, giving your films the best possible sharpness
It is by far better than even a HD video by the way. The 35 mm lens is for
smaller rooms and audiences, the 50 mm for settings like classrooms.
These Siemens projectors represent the best of German engineering in the 50s
and by far surpasses the more common Bell & Howell.