SECAM

Long ago, TV was black and white.

Then, people found a way to show color. This was called SECAM. It was used in France and Russia.

SECAM sends two things at once. It sends a black and white picture. It also sends color information. These two parts travel together as one signal.

This system helped people see color on their screens. It worked well for long distances. Some countries used it for a long time. Now, most people use new digital TV. It is still amazing how we see color!

Long ago, most TV shows were only black and white.

Then, scientists found a way to add color. One major way was called SECAM. This name is French for an electronic color system with memory. It was used in France, Russia, and many parts of Africa.

SECAM works by sending two parts in one signal. The first part is called luminance. This is the black and white image. The second part is called chrominance. This is the color information. SECAM puts the color on top of the black and white image. This allowed old black and white TVs to still work. They would just show the luminance part.

SECAM was very helpful for long distances. In Russia, TV signals had to travel very far. Long cables can sometimes change a signal. This can make the picture look wrong. However, SECAM signals did not have this problem. It was also used in East Germany. Some TV sets there could use both SECAM and another system called PAL. Most countries have now moved to digital TV. But SECAM was a big part of TV history.

SECAM is a special way to send color images through a television. The name is French for an electronic color system with memory. It was one of three main ways to show color on old analog TVs. Other systems were called PAL and NTSC. SECAM was used in France, Russia, and many countries in Africa. It was also used in parts of Europe and the Middle East.

To make a color picture, the system sends two parts together. The first part is called luminance, or luma. This part carries the black and white image. The second part is called chrominance, or chroma. This part carries the color information. The color is added on top of the black and white image. This way, old black and white TVs could still work. They would only show the luma part of the signal.

A team led by Henri de France began working on SECAM in 1956. They worked at a company called Compagnie Française de Télévision. Later, this company was bought by Thomson. The first version, called SECAM I, was proposed in 1961. Scientists made improvements called SECAM II and SECAM III. The SECAM III B version was finally used for general use in 1967.

France officially launched the SECAM standard on October 1, 1967. On that day, a presenter named Georges Gorse said, "Et voici la couleur!" This means "And here is color!" At that time, a color TV set cost 5,000 French new francs. This was a lot of money compared to a pocket book. Only about 1,500 people watched the very first color program. By 1968, only 200,000 sets had been sold in the country.

SECAM was very useful for countries with long distances. In the Soviet Union, TV signals traveled through very long cables. These long paths can sometimes change a signal's strength or shape. This can make a picture look wrong, but SECAM signals do not have this problem. Some TVs, like the RFT Chromat from East Germany, could even use two systems. They had a decoder that worked for both SECAM and PAL.

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.

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.

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.

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.

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.

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.

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.