> I've got a radio engineer that is insisting that the Sony PCM-F1/Betamax, PCM-F1 Beta HiFi tapes are not of a true PCM digital lineage.
Unless your radio engineer cares to explain exactly what his/her point is, the statement doesn't make any particular, obvious sense. You can view an F1 tape on a video monitor, and see the columns of black and white dots that represent the 0s and 1s. They're the (strategically interleaved, parity- and ECC-supplemented) output of the unit's analog-to-digital converter.
I mean, there is a certain theoretical level on which all digital recording is ultimately analog, along with all digital logic circuits of any kind, since signals are continuous and the transitions between the high and low (1 and 0) voltage levels are never perfectly instantaneous. In a sense, the "digitalness" of a recording (as with any logic circuit) lies in the way those signal levels are interpreted. And yet there is another, even deeper theoretical level on which all analog recording, or other signaling, is ultimately digital, because of quantum mechanics.
But if that's the level your radio engineer is thinking on, then it's not really about the PCM-F1, is it?
For that matter, the Sony and JVC professional systems throughout the 1980s also used "pseudo-video" signals, since video recorders with adequate bandwidth (and almost adequate reliability) were readily available items that didn't need to be invented. The only serious competing system at the time, Thomas Stockham's "Soundstream" system, used digital instrumentation recorders as its storage device--but the differences in principle are rather small.
--best regards