VLF enthusiasts, take note: The SAQ Alexanderson alternator will be on the air for “Alexanderson Day,” Sunday, July 3, for a full-day event that includes both VLF transmissions and Amateur Radio HF activity from SK6SAQ, the ham station at the Grimeton heritage site in Sweden. The Alexanderson alternator — an electromechanical radio transmitter — is named after the Swedish engineer Ernst F.W. Alexanderson, who emigrated to the US in 1902 and spent many years working General Electric and RCA.

On Alexanderson Day, there will be two separate, but identical, 17.2 kHz transmissions, at 0900 UTC and at 1200 UTC. The Alexanderson alternator will be started 30 minutes before transmissions begin. On Alexanderson Day, Christmas Eve, and at other times during the year, the only functioning Alexanderson alternator transmitter in the world is used to transmit short CW messages on 17.2 kHz, easily heard in Europe. The transmitter is preserved as a historical remnant of early (1920s era) radio technology.

Because of the extremely low frequency, modern VLF enthusiasts can listen for the SAQ by using a communication receiver with an upconverter or a receiver designed to receive VLF transmissions directly. In recent years, software-defined radios have been used to receive SAQ’s transmissions.

In addition, Amateur Radio station SK6SAQ will be active on 7035, 14,035, or 21,035 kHz, CW, and on 3755 kHz, SSB. Two stations will be on the air most of the time.

Reception reports may be submitted via e-mail. QSLs for SK6SAQ are invited via the bureau or direct. — Thanks to Lars Kalland, SM6NM