In the early 1950s, the BBC almost invented the world’s first broadcast quality video recorder. VERA, the Vision Electronic Recording Apparatus, filled a small room and in pre-metric days boasted 20.5-inch spools of half-inch tape running at 200 inches per second to record 15 minutes of 405-line monochrome pictures and mono sound. Two machines were ganged together to make continuous recording possible.
Previous attempts at video recording had failed because of the difficulty of capturing low frequencies on tape that had to move fast to capture high frequencies. VERA simultaneously recorded three tracks, two video and one audio. The 3MHz picture signal was split into two bands, one 0 to 100kHz, the other 100kHz to 3MHz. The high band was recorded normally on one track, like very high-fidelity audio. The low-band frequency modulated a high-frequency carrier on the other track. Complicated braking systems were needed to start, stop and rewind the tape without snapping or stretching it.
The recording heads were hand-made, with insulating material hand sheared from mica sheet. The tape gave best results only after a few dozen playings had polished its surface and improved contact with the heads. The BBC used VERA for a few broadcasts, but dropped the project in 1958 when the UK and Europe adopted a new 625-line standard which needed a 5MHz bandwidth. Running VERA faster to achieve this would have reduced recording time to only a few minutes per reel.
US company Ampex had by then proved that its Quadruplex recorder, first demonstrated in 1956 under team leader Charles Ginsberg, could record a full hour of 625-line TV on a single spool. It did so by running the tape slowly but mounting the heads on a wheel and spinning them rapidly across the tape width. Although he did not like to talk about it, a young Ray Dolby was part of the Ampex team. Dolby later became famous for Dolby Noise Reduction, but that’s another story.
This article was reproduced from the December 2021 issue of Practical Electronics, which is the UK’s premier electronics, computing, and maker hobbyist magazine, in association with Tekkiepix. which is UK technology journalist and broadcaster Barry Fox’s project to preserve the visual history of pre-Internet electronics based on his personal collection of tens of thousands of photos collected over forty years.