Radio: Color for Everyone?

Into the long squabble over color television a husky new contender shouldered its way last week. Chromatic Television Laboratories, an affiliate of Paramount Pictures Corp., brought forth a new, all purpose television tube which can: 1) receive any kind of color television that has been proposed so far, including both the CBS and RCA systems; 2) receive ordinary black & white broadcasts; 3) switch itself automatically from one system to another. The tube’s inventor: Nobel Prizewinner Ernest O. Lawrence, inventor of the cyclotron, who built the first model in his Berkeley (Calif.) workshop.

If the new tube lives up to its sweeping advance notices, the whole color fight may soon be over. Each studio will be able to telecast in any system it prefers, or in black & white. Any set equipped with the new tube can show any program on the air.

Red, Green, Blue. The basic plan of the Lawrence-Paramount tube looks so simple to the experts that—if it really works out—it will have inventors all over the country kicking themselves for not having thought of it first. Just behind the curved face of the tube is a flat glass “viewing plate” on which are printed fine parallel lines of colored phosphors, i.e., materials that glow in red, green or blue when struck by speeding electrons. The lines are arranged in groups, each containing one line of each color, with 450 groups in all. The plate also carries a strong electric charge to attract electrons.

Behind the line-covered viewing screen is a “grid” of fine parallel wires, one wire for each group of phosphor lines. At the narrow rear end of the tube is a single electron gun that shoots a slender beam of electrons through the wire grid at the viewing screen. As in all television tubes, the electron beam scans at a rapid rate, painting an ever-changing picture on the screen of phosphors.

Electron Switching. The trick in color television is to make the electrons that represent red, for example, hit the phosphor that glows in red. In the Lawrence tube, the wire grid does this switching job. It is hooked up, through the proper electronic apparatus, to the signal that comes over the air. When the signal tells it that certain electrons represent red, the wires of the grid are charged with enough electrical potential to focus the electron beam onto a line of red phosphor. When “green” electrons come along, it switches them to green phosphor, etc. So, jumping from phosphor to phosphor, the electron beam paints its picture in full color.

When receiving CBS color television, the tube will presumably paint a whole picture in red, then another in blue, and a third in green—changing from one color to another so quickly that the eye sees all three colors at once. When receiving the RCA color system, the tube will have to work differently, for RCA color television is made up of colored dots that arrive on the screen simultaneously. But the tube’s sponsor says that only simple auxiliary apparatus is needed to make it digest both systems.

Proof to Come. So far, the Lawrence tube has been demonstrated only to a few scientists and newsmen. The tube shows color all right, but the quality is not quite up to the older systems. This may be because the most advanced tube built so far is a hand-built laboratory model that still has bugs in it.

One of the big claims for the new tube is that it can be manufactured both easily and cheaply. Most of its parts are like those of ordinary black & white tubes. The extra parts should not add more than $30 to the cost. Within a few weeks production will start in a Connecticut factory. When professional, factory-made tubes are available, the public will have a chance to decide whether a Nobel-Prizewinner has, in his spare time, licked the whole electronics industry.