<prompt> Ikomidi leNational Television System Committee lasungulwa ngo-1940 yi-United States Federal Communications Commission FCC ukuze kuxazululwe izingxabano phakathi kwezinkampani mayelana nokwethulwa kohlelo lwe-analogue lwe-TV kuzwelonke e-United States. NgoMashi 1941, ikomidi lakhipha indinganiso yezobuchwepheshe yethelevishini emnyama nomhlophe eyakhelwe esinconyweni sango-1936 esenziwe yiRadio Manufacturers Association RMA. Intuthuko yezobuchwepheshe yendlela ye-vestigial side band yavumela ithuba lokukhulisa isinqumo sesithombe. I-NTSC yakhetha imigqa engu-525 njengokuvumelana phakathi kwe-RCAs 441-scan line standard esivele isetshenziswa yi-RCAs NBC TV network kanye nesifiso sikaPhilco noDuMont sokwandisa inani lemigqa yokuskena ukukhetha phakathi kuka-605 no-800 okujwayelekile. Isilinganiso sefreyimu izithombe ngomzuzwana, esakhiwa yimigqa emibili ehlanganisiwe emikhakheni emnyama nomhlophe eyayakhiwe ngesincomo sango-1936 esenziwe yi-Radio Manufacturers Association  <response>: 525 izinkulungwane 