When a motor is a radio

[Mike Watterson]

From IRTS News:

The unique Alexanderson alternator from 1924, with the call sign SAQ, is scheduled for two transmissions on VLF 17.2 kHz CW on June 30th. Almost a hundred years ago, on December 1st, 1924, the long wave transmitter at Grimeton Radio Station, with the call sign SAQ, was put into commercial operation. Transmissions were across the Atlantic Ocean to a receiving station in Riverhead and with the replying transmitter station in Rocky Point, both on Long Island, NY, USA. The other transmitting and receiving stations in the RCA network are now long gone but SAQ has been preserved as a World Heritage Site and is still operational. The design and manufacturing of such a robust a reliable radio transmitter was a monumental achievement by the Swedish-born inventor Ernst F.W. Alexanderson.

To receive the message, you can try using a wire as long as possible connected to the microphone socket of a laptop or PC soundcard. The soundcard can then be used as a receiver allowing you to try to receive the transmissions.

[Kalee20]

Thanks for alerting us to the next switch-on day!

I'm puzzled about the thread title though, the alternator isn't a motor... enlighten!

[Mike Watterson]

It is when it's a load to suitable AC drive, instead of being rotated and having a load.

See also Dynamo vs DC motors and rotary converters.

[ppppenguin]

I think that's a rather odd distinction. I know there is a symmetry between motors and generators but the important part of the TX is the Alexanderson alternator: https://en.wikipedia.org/wiki/Alexanderson_alternator It's hard to conceive of putting in high frequency power and getting rotation out, though it's probably theoretically possible.

[Mike Watterson]

No, you'd not want to do that. It would be challenging even on a car alternator (apart from fact the connections are inside with electronics & rectifiers). I replaced the rectifiers in an alternator once. Not doing it again ever.

However certainly an unlikely transmitter.

My poor attempt at humour. "When an alternator is a transmitter" would have been less confusing and more accurate.

[Doodlebug]

They have shown live the long preparations and start up in the past.
Check their web site.

[ppppenguin]

However you look at it, it's a fabulous installation. Well deserving of its designation as a World Heritage Site.