Last week in history

[DonRotolo]

Al shut down Analog TV as well. I vote for a weekend session...

The VCR was a revolution based on a simple idea: Scan the tape faster, much faster, than ever before. A typical 1/4" reel-to-reel tape speed is 7.5 inches per second, giving a maximum frequency reproduction (limited by the tape) of about 16 kHz. Video has significant energy over 2 MHz, more than 100 times higher. Early experiments tried running tape at hundreds of inches per second, but as you can imagine it wasn't very practical (or good).

Someone brilliant at Ampex wondered why they had to move the tape so fast - instead, they moved the tape head past the tape very fast, using a rotating drum to 'stripe' the tape at a diagonal*. It worked, and made Ampex THE tape company for quite a long time.

Look it up, the technology is fascinating.

*Helical, actually, but practically diagonal.