Editing Composite video (section)

== Modulators ==
{{Unreferenced section|date=August 2023}}
Some devices, such as [[videocassette recorder]]s (VCRs), [[video game console]]s, and [[home computer]]s output composite video. This may then be converted to FM RF with an [[RF modulator]] that generates the proper carrier (often for channel 3 or 4 in [[North America]], channel 36 in [[Europe]]). Sometimes this modulator is built into the product (such as video game consoles, VCRs, or the [[Atari]], [[Commodore 64]], or [[TRS-80 CoCo]] home-computers), is an external unit powered by the computer ([[TI-99/4A]]), or with an independent power supply.{{efn|In the United States, using an external RF modulator frees the manufacturer from obtaining FCC approval for each variation of a device. Through the early 1980s, electronics that output a television channel signal were required to meet the same shielding requirements as broadcast television equipment, thus forcing manufacturers such as Apple to omit an RF modulator, and [[Texas Instruments]] to have their RF modulator as an external unit, which they had certified by the FCC without mentioning they were planning to sell it with a computer. In Europe, while most countries used the same broadcast standard, there were different modulation standards (PAL-G versus PAL-I, for example), and using an external modulator allowed manufacturers to make a single product and easily sell it to different countries by changing the modulator.}}

Because of the [[digital television transition]] most television sets no longer have analog television tuners but DVB-T and ATSC digital ones. They therefore cannot accept a signal from an analog modulator. However, composite video has an established market for both devices that convert it to [[channel 3/4 output]]s, as well as devices that convert standards like [[VGA]] to composite, therefore it has offered opportunities to [[repurpose]] older [[composite monitor]]s for newer devices.

=== Demodulation loss ===
The process of modulating RF with the original video signal, and then demodulating the original signal again in the TV, introduces losses including added noise or interference. For these reasons, it is best to use composite connections instead of RF connections if possible for live signals and sample the source FM RF signal for recorded formats. Some video equipment and modern televisions have only RF input.