Thursday, December 13, 2007

An End of Year puzzle.

What links the following numbers: 40, 87 and 4.43361875?

The last one is the easiest, or rather, it's one you know or you don't. 4.433 etc is the frequency in MHz of the PAL colour subcarrier. What do you mean, you didn't know that? To TV engineers from the Analogue era - either service technicians or broadcast engineers - it's as familiar a figure as 625 lines, or today's 720 or 1080 magic numbers. And this year marks the 40th birthday of the first PAL colour TV services. Soon it'll be no more, as we move to digital switchover: we use the term PAL loosely to describe the 625 line TV standard, but strictly speaking it's only applicable to the analogue broadcast signal and the CVBS analogue signal that comes out of the back of VHS and DVD players. All the rest: S-video, DV, HD of course, even component and SDI signals - they're not PAL encoded. So it'll be farewell to the invention of Dr Walter Bruch of the Telefunken company. As you might know, Telefunken held the patents for PAL, or, more accurately I suspect, for the decoding circuitry of PAL, which included that high technology of the day, the analogue quartz delay line. I was told that, when the first Trinitron receivers came on the market, Sony were unable or unwilling to purchase licences, and so the sets discarded half the colour information and decoded the TV signal as a modified form of the US NTSC signal. Hence the 'hue' knob on these sets which changed the displayed signal to the viewers' whim, be it blue or green. Farewell too to the 'Hanover Bars' of which more another time.

And the 87? By coincidence it's also the 40th anniversary of the Neumann U87 microphone, which, as their own website describes, is probably the most famous model of studio microphone in the world. Should you be so inclined, there's a special anniversary edition of the U87 for sale in a 'classic' case which looks very fine indeed, an upmarket suitcase if ever I saw one. Ogle it here.

More musings on these anniversaries in the next podcast, when I get time and studio space to spare.