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SECAM

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SECAM is an analog color television standard used for broadcasting. The name is an acronym for the French phrase "Système Électronique Couleur Avec Mémoire," which means electronic color system with memory. It was one of three major analog color standards used globally. The other two were NTSC and PAL. SECAM was primarily used in France, Russia, and various territories across Europe and Africa. It served as a vital way to transmit color images before the world moved to digital broadcasting.

Spectre SECAM NICAM
Spectre SECAM NICAM

To understand how SECAM works, you must look at how it handles different types of information. The system uses composite video, which means it transmits different parts of an image together as one signal. This signal includes luminance, also called luma, which carries the monochrome or black-and-white image. It also includes chrominance, or chroma, which provides the color information applied to that monochrome image. By combining these, the system allows color to be added to the brightness. This method also ensures that older black-and-white television sets can still receive the signal and display the luma part.

Spectre SECAM NICAM
Spectre SECAM NICAM

The technical process involves specific frequencies to keep signals from interfering with each other. In an 8 MHz standard, the signal is split into video and audio. The luma carrier is located 1.25 MHz above the channel's frequency. The audio carrier is located 6 MHz above the luma carrier. To add color, SECAM places a chroma carrier 4.4336 MHz above the luma carrier. This specific frequency is chosen so that the harmonics of the signals stay apart. This helps minimize crosstalk, which is when one signal accidentally interferes with another. Because the human eye is more sensitive to green light, the system focuses on sending red and blue color difference signals. This saves bandwidth while maintaining high perceived image quality.

Spectre SECAM NICAM
Spectre SECAM NICAM

The history of SECAM began in 1956. A team led by Henri de France started development at the Compagnie Française de Télévision. This company was later acquired by Thomson. One reason for developing SECAM was to solve the "tint problem" found in the NTSC system. In Europe, some also believed the goal was to protect French equipment manufacturers. The first version, SECAM I, was proposed in 1961. After several studies to improve image quality, versions called SECAM II and SECAM III were developed. The SECAM III B version was eventually adopted for general use in 1967.

Chromat-2062 Farbfernseher 6400dpi 1979
Chromat-2062 Farbfernseher 6400dpi 1979

France officially launched the SECAM standard on October 1, 1967. During the launch on the second national network, France 2, a presenter named Georges Gorse declared, "Et voici la couleur!" This translates to "And here is color!" At the time, color television was very expensive. A single set cost 5,000 French new francs, while a pocket book cost only about 1 NF. Because of the high cost, popularity grew slowly. Only about 1,500 people watched the first color program. By 1968, only 200,000 sets had been sold, which was much lower than the expected million.

Chromat-2062 Farbfernseher 6400dpi 1979
Chromat-2062 Farbfernseher 6400dpi 1979

SECAM was particularly useful for the Soviet Union due to its geography. Soviet technicians at Moscow's Telecentrum worked on the standard. They even created an incompatible variant called NIIR, or SECAM IV. The Soviet Union had extremely long distribution lines between stations and transmitters. These long cables or microwave links can cause variations in amplitude and phase. These variations can distort other signals, but they do not affect SECAM signals. In East Germany, the government adopted SECAM III B in 1969. This was partly due to political tensions during the Cold War.

Chromat-2062 Farbfernseher 6400dpi 1979
Chromat-2062 Farbfernseher 6400dpi 1979

As technology changed, SECAM began to decline. In East Germany, people often bought PAL decoders to watch different signals. Later, East German manufacturers produced dual-standard sets like the RFT Chromat. These sets could decode both PAL and SECAM. Eventually, most countries switched to Digital Video Broadcasting (DVB). This is the modern pan-European standard for digital television. However, the principles of SECAM live on. The idea of transmitting color components sequentially was used in the MAC standards. Even modern digital video uses 4:2:0 sampling, which relates to how color resolution is handled.

Chromat-2062 Farbfernseher 6400dpi 1979
Chromat-2062 Farbfernseher 6400dpi 1979
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File:Chromat-2062 Farbfernseher 6400dpi 1979.jpg
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File:Spectre SECAM NICAM.png
Spectre SECAM NICAM.png
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