All but one analog television system began as black-and-white systems. Each country, faced with local political, technical, and economic issues, adopted a color television system which was grafted onto an existing monochrome system, using gaps in the video spectrum to allow color transmission information to fit in the existing channels allotted.1
Different countries use different technical systems for recording and playing back video signals. A list of TV standard by geographical location can be found here: TV standards by country.
Each video standard requires a different playback system (VTR, monitor and any attached video processing equipment). Some manufacturers of video equipment make multi-standard video equipment, where a television standard can be manually or automatically selected. If an attempt is made to play a tape recorded in one standard with equipment meant for playback of another standard, different types of video signal distortion can occur.
Attempting to play an NTSC recording in PAL player will result in the tape playing too slowly, and the image will be distorted beyond recognition with the audio pitched too low. If attempting playback of a PAL recording in an NTSC machine, the tape will play too fast and the audio will be pitched too high.2
Can it be fixed?
If a program is recorded in PAL standard, a PAL standard (or multi-standard) playback machine and monitor are required to display the image properly. The same is required for programs recorded with NTSC or SECAM signals. All equipment in a given signal chain must have an identical standard, so any TBC or other signal processing equipment must match standards with the playback VTR, video monitor and sync or signal generator, if present. Some monitors automatically detect the appropriate standard, so no adjustment is required.
References
1. Wikipedia, Broadcast television systems. ↩
2. Johannes Gfeller, Agathe Jarczyk, and Joanna Phillips, “Incompatibility Between Television Standards” in Compendium of Image Errors in Analogue Video (edited by Swiss Institute for Art Research, Zürich: Scheidegger & Spiess, 2012), p.72, videos 19-24. ↩