There will be no Alexanderson Day over-the-air VLF transmission on July 2 from SAQ, the Alexanderson alternator station in Sweden. SAQ periodically schedules transmissions with the nearly century-old behemoth that operates on 17.2 kHz from the World Heritage Grimeton Radio Station. SAQ said the event was cancelled due to ongoing maintenance work at the site.

The station will still observe Alexanderson Day with activities that include two startups of the Alexanderson alternator and a “local” transmission. These events will be streamed via YouTube. The site will be open to visitors.

Dating from the 1900s, the Alexanderson alternator — essentially a massive ac generator run at extremely high speed and connected to an extensive antenna system — can put out 200 kW but typically is operated at less than one-half that power level. Once providing reliable transatlantic communication, it is now a museum piece and only put on the air on special occasions. The unit at SAQ was built in the 1920s.