View Full Version : A book review:


earlyfilm
12-26-2015, 09:43 PM
Always interested in all forms of technical history, I recently borrowed a book titled, "The Engineering Book: From the Catapult to the Curiosity Rover, 250 Milestone in the History of Engineering", by Marshall Brain.

Just a sample of the deep research that went into this book, I'll quote from page 192, which is titled:


1939 Color Television: Peter Carl Goldmark (1906-1977)

"In the 1950s, there were millions of black and white TVs in use, receiving free broadcast television channels. How did engineers bring color TV to the masses without orphaning all those existing TV sets? .....

This problem was solved in a remarkable way: the color information became encoded as a sine wave rippling along the normal, existing B&W Signal. (1) Older Black and white TVs would ignore the new sine wave, while color TVs could decode it. A first attempt, developed by German-Hungarian engineer Peter Goldmark (2) for RCA in 1939, used a mechanical color wheel rotating in front of the display. (3) This had a number of problems: it suffered from flicker and the mechanical color wheel (4) was thee times bigger than the screen itself."

End quoted material and a little fact checking here.

(1) The color synchronizing burst was a sine wave, but the color information was a two channel phase modulated analog signal.

(2) Peter C. Goldmark never worked for RCA. He was hired by the Columbia Broadcasting System in December 1935 and started worked there on January 1st, 1936 and continued working with the various divisions of CBS until he was terminated in 1972, at approximately the same time as his division's patient on the first practical method of manufacturing color three gun CRTs expired.

(3) In 1939 RCA had tested color wheel cameras, but had difficulty getting enough light through them with the iconoscope cameras of the era and discontinued testing during WWII and decided to concentrate on perfecting the B&W camera.

(4) Goldmark had redesigned the wheel to about 2 and 1/8th times larger than the screen by 1941. He also suggested use of a color drum instead of a wheel, which was much smaller.

James