It looks pretty small. I bet the motor is up to 2 kW considering also the siren age.

It looks like a Japanese hand operated siren.

What about these compact static phase converters? They don't seem to appear nowhere in Europe.

Thanks for your comments! The problem is the lack of three phase current in my house, so the video probably won't come soon.

It took a long time and quite a lot of drilling, machining, welding, grinding etc. The siren is now fully functional. Painted of course in its original colors.

Very interesting. I wonder how this modulation effect can be generated with an electromagnetic horn. Certainly not by reducing the voltage, that would make the horn to be more quiet. Maybe with a frequency converter? Also I wonder if this effect was originally used as a signal.

Another update: The stator has been welded. That was not an easy task because of the special cast iron alloy it's made of. Also the shaft had to be cut, otherwise the upper motor plate couldn't be removed. It turns out that the shaft has a slightly conical shape! The shaft bore on the rotor has the ...

The machine shop has finally pulled out the rotor. It was badly stuck because of the shaft distortion and had to be pressed. The guy told me he applied over 8 ton force to extract it! No wonder why it wouldn't move with the puller! Next step is the shaft replacement.

Yes, that's what I meant. I'm thinking its not quite defeat and makes sense to have the shop do it since you need a new shaft anyway. I do recall reading that when having shaft work done on a motor make sure the shop knows motors because the shaft can only be pressed out one direction which is hard...

If you could support the back side of the rotor maybe place a rod on the shaft and hammer it out? And I just used a propane torch, not an oxy acetylene. Do you mean support the rotor and let the motor hang below when the shaft is hammered? That could work I suppose... Anyway I'm considering to visi...