South Dublin Radio Club had an interesting Zoom presentation on the 20th of October 2020 about the historic SAQ transmitter in south-west Sweden.
This transmitter operated at the very low frequency of 17.2 kHz and was established in 1924 to send telegrams across the Atlantic to the USA. Not long after its opening, low frequency stations of this type were superseded by those using the more efficient short wave bands.
What makes SAQ unique is that it is the last surviving transmitter of its type in that it generated the radio signal by mechanical means. See the photo below...
The electric motor on the right provides the mechanical force. The gearbox steps up the speed by a factor of three. The RF generator on the left is an alternator operating at 17,200 Hertz or 17.2 kHz.
The transmitted power is then fed to an antenna which is 2.2 kms in length.
The one-hour presentation is now available on YouTube...
Links...
