You’re all probably aware that John Logie Baird was the first person to demonstrate television, and his “Televisors” were the first mass produced sets. He was the first to successfully send television signals long distance via a phone line (between Glasgow and London) and was also an important early developer of colour television.
What you may not know is that he was the first to record television signals using his Phonovision system. The medium was ordinary 78 rpm wax phonograph masters. He made various test recordings from 1927 to 1929.
However, he made no public demonstrations of the playback of these Phonovision disks, and it is thought likely that he could not have done so in a way that produced continuous and meaningful video.
In the 1980s, Donald McLean developed means of recovering video from these experimental disks.
This is a fragment from a disk labelled “28th March 1928 – Miss Pounsford”
Superior results were achieved by other developers in the early 1930s using aluminium disks at higher speeds.
http://www.tvdawn.com/earliest-tv/phonovision-experiments-1927-28/