This isn't just a big motor or a electric utility's generator - it is a vintage early 1900s radio transmitter, operating on a frequency around 17.2 kilocycles, with a wavelength of 17.4 kilometers (nearly eleven miles long) . It is an Alexanderson Alternator, the first kind of "pure" sinusoidal continuous wave RF generator, which was in use long before sufficiently powerful vacuum tubes became the norm for radio and transmission.

The transmitter, the heart of which is an alternating- current generator (alternator), was developed by the Swedish engineer Ernst Alexanderson, pioneer in radio, employed at General Electric in Schenectady and chief engineer at Radio Corporation of America (RCA).

The earlier "spark" transmitters generated a harsh, noisy relatively broad spectrum, Station is located in Grimeton, in Sweden. It is still operational, and transmissions are made (in International Morse Code) on various occasions. The call letters SAQ would be sent as dot-dot-dot dot-dash dash-dash-dot-dash.

Of course such a transmiter needs to have a suitable [id=285263255; antenna system].

To give a comparison of the actual wavelengths, an AM broadcast station on 1000 KHz (1 MHz) is 300 meters, or about 984 feet long, and an FM station on 100 MHz has a wavelength of three meters, or just an inch short of ten feet long. And an 880 MHz cellular telephone has an operating wavelength of 34.1 cm, or about 13.4 inches long.

More information can be found here: http://www.alexander.n.se/ languages are Swedish, English and German.