|The 200kW Alexanderson alternator|
I used a Perseus SDR and a home-made miniwhip to Roelof PA0RDT's design at about 8m high. The signal was loud at about S9 +20dB - much better than I thought it would be, but this was down to the brilliant tiny antenna.
I managed to extract the audio and make an MP3 file from it, so you can hear it yourselves and decode the CW if you wish. Note that at the end of the MP3 file you'll hear the tone die away as they switch the alternator off and it slows down!
There are few glitches as the computer struggled to record it, but you only lose the odd character!
Download the MP3 file