Understanding the numbering of these Beograms is really quite easy: the ‘V’ in ‘608V’ means that it was powered with AC voltage and ‘F’ meant that it had a built-in preamplifier. The designation 608, 609 and so on, indicated the year the product was marketed.
Beogram 608 was a turntable without a built-in RIAA preamplifier and was produced for the 1962 season (internally many were date-stamped e.g. September 1961 would indicate the year it left the factory).
Beogram 42 was basically the same as Beograms 6xx but with a larger platter and longer tonearm. The longer tonearms could, like the preamplifier and platter, be refitted.