In Australia before the official introduction/launch date of PAL colour television in 1975 it was a requirement of the then, now defunct, broadcasting regulator, the ABCB - Australian Broadcasting Control Board for television stations to remove any colour content from their TV broadcasts. (During the conversion period leading up to the launch stations would run a mixture of B&W and colour material within their stations).<p>To comply, stations would strip the colour burst from the TV
video sync block before it was broadcast. This infuriated many propeller-head techies and nerds, myself included.<p>To overcome the problem, the 4.43 MHz colour subcarrier in the broadcast video which wasn't deliberately stripped out was used to reconstitute the colour burst. This was achieved by modifying standard PAL colour TV sets (which weren't that difficult to obtain) with the addition of some subcarrier-extracting filters and appropriate phase-locking/modifying circuitry. This was a bit tricky, as the reference phase was no longer there and the fact that it was a PAL signal (PAL - Phase Alternating Line encoding).<p>In fact, I recall at the station I was working for at the time we had a modified TV set in the engineering department working in colour from off-air signals (one of my colleagues was a past master at tweaking up sets this way).<p>Perhaps a bit of broadcasting history trivia but it sure shows the colour recovery technique in this story wasn't the first effort.<p><i>Edit: Incidentally, the same trick was used on source material such as quadruplex videotape that already had the burst stripped at other locations.</i>