Spent the day listening in on a historic radio station.
Today is Alexanderson Day, when the historic Alexanderson VLF transmitter at Grimeton in Sweden (call sign SAQ) transmits a message to the world.
The Alexanderson transmitter is remarkable in that it is the last operational VLF (Very Low Frequency) electro-mechanical transmitter.
It has no valves or semiconductors; it uses a mechanical rotating alternator to produces the 17.2KHz VLF RF current.
This appeals to my latent Steampunk tendancies!
The Very Low Frequency is chosen for it's long distance propogation; this was Sweden's only link with the outside world during war years.
SAQ's transmissions can be recieved in North America.
https://alexander.n.se/the-radio-station-saq-grimeton/the-alexanderson-transmitter/?lang=enUsing a home-made VLF reciever, today's message was:
CQ CQ CQ DE SAQ SAQ SAQ
THIS IS GRIMETON RADIO/SAQ IN A TRANSMISSION USING THE ALEXANDERSON 200KW ALTERNATOR ON 17.2KHZ.=
IN VIEW OF THE PRESENT PANDEMIC COVID-19 WE WANT TO PAY TRIBUTE TO ALL PARTIES CONCERNED WITHIN HEALTHCARE KNOWING THEIR EFFORTS WILL PAY EFFECT EVENTUALLY.=
SIGNED: WORLD HERITAGE GRIMETON RADIO STATION AND THE ALEXANDER-GRIMETON VETERANRADIOS VAENNER ASSOCIATION <Message Ends>=
FOR QSL INFO PLEASE READ OUR WEBSITE:
WWW.ALEXANDER.N.SE=<Message Ends>
DE SAQ SAQ SAQ <Closing Down>
VLF Rx site by
Ron Lowe, on Flickr
The VLF Rx station
CQCQCQ-DE-SAQSAQSAQ by
Ron Lowe, on Flickr
Spectral plot showing SAQ at 17.2KHz
SAQ-Audacity by
Ron Lowe, on Flickr
The processed audio in Audacity. This is SAQ signing off.
My Morse is not good enough to catch it all real-time, so I recorded it and used Audacity to pause and re-play sections.
You can also see the Morse graphically on-screen.