European color television standards-the secam system

The creation of European color television standards from the American NTSC system was outlined in an article published in the preceding issue and brief descriptions of the NTSC and PAL systems were given. Both these systems use subcarrier quadrature-amplitude modulation. The present article is concerned with the SECAM system, which utilizes frequency modulation. A number of improvements have been incorporated in the Oceanic-Radio color receiver including a new technique for combining the red and blue chrominance signals to produce green that prevents variations in supply voltage from affecting the ratios of the chrominance signals during the process.