It should probably be noted somewhere that this audio file "sounds like PSK31" but actually does not contain the information stated in the caption. This is likely due to the conversion using a lossy audio codec [1] that damages the inter-element phase relationships contained in the original signal. For anyone curious, this conversion also introduces an artifact, likely from the sampling frequency of the digital capture (not contained in the original QPSK signal being digitised) which can be seen at 2025 Hz by observing a spectral display of this signal. Kz1o (talk) 15:59, 6 July 2020 (UTC)