Mallory tech book on TV in 1942

[wa2ise]

Originally Posted by David Roper

For a book with a copyright of 1942, it sure wasn't very up to date. The FCC set the 525-line standard with FM sound in 1941.

I wonder what sort of lead time a book has from its last edit to when it hits the bookstores? And when the copyright is asserted? It seems likely the book reflected the state of the art a year or two before its copyright date.

As for FM sound for TV, I understand that RCA's Sarnoff was really unhappy about that. As he didn't want RCA to license Armstrong's FM patents, as Armstrong became an ex-friend... But the FCC did move the FM radio band from 45MHz to today's 100MHz band, this move Sarnoff hoped would kill FM radio, to cut competition to RCA's new baby, television. And Sarnoff didn't want to build all new FM broadcast stations for NBC for FM radio. Before this, RCA asked Armstrong to develop a noise free radio system, and came up with FM. I suspect Sarnoff wanted a noise free AM radio receiver, that would receive existing AM broadcast stations. If Armstrong mentioned that FM would make an excellent sound channel for television, helping make it the killer app it did become, maybe Sarnoff would have thought it a great idea...

Intercarrier AM would really sound bad, but maybe an independent sound IF and detector would have sounded not as bad. You could build as wide an AM audio bandwidth as you'd want, the video is really just very wideband AM modulation. But you'd also hear residual high freq video with AM, which FM's capture effect would ignore.