Thanks, Steve, for allowing FLAC audio attachments!
And Klaas, yes, I have many cassette tapes containing classic (120/128 line) SSTV signals that I recorded off-the-air from around 1979 to 1982 when I was just a teenager (and SWL). In fact, it was my desire to revisit those old tapes that provided the incentive for me to create my scan converter. I'm still going through them as time permits, and reliving old memories.
Frequency response was never really an issue with tape recordings, but poor tape speed regulation (wow and flutter) would often cause horizontal jitter that grew progressively worse as the horizontal scan moved towards the right side of the image. With each line video line came a new horizontal sync pulse that brought the horizontal sweep back into alignment, even if it was only briefly:
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The image above was transmitted by AC5D of Stigler, Oklahoma (USA) on 14.230 MHz more than 40 years ago. Not only did I capture it on tape, but the original transmission made by AC5D was probably a tape playback of his own.
I seem to remember he used an analog sampling vidicon camera, and produced many clever and artistic "programs" by concatenating individual SSTV frames together on tape. Then he would play his various "programs" during a QSO by selecting the appropriate tape.
Today's non-interactive SSTV is incredibly boring and impersonal by comparison. Sadly, AC5D is probably a silent key, today. His callsign has been re-issued to someone else.
73 de John, KD2BD