Want a VLF receiver? Just filter the antenna to the appropriate frequency and plug it into your soundcard. This is a Spectrogram display of 14-20kHz showing SAQ between two other signals. The strong "GBR" signal is from Rugby Radio Station only 50km from me.
Having missed the early session due to problems with the DC power supply to the alternator they came on air at 11:40 UTC and stayed on until 13:00. I don't know how the TX is keyed but it seems capable of pretty fast speeds. You can just see a spacer, about 20dB below the main signal, between the dots and dashes.
I made an audio recording from my old MV61 selective level meter. Listen to SAQ in RealAudio.