<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 kuncomo yango-1936 eyenziwe yi-Radio Manufacturers Association RMA. Ukuthuthuka kwezobuchwepheshe kwethekhinikhi ye-vestigial band band kwavumela ithuba lokukhulisa isinqumo sesithombe. I-NTSC yakhetha imigqa yokuskena engama-525 njengokuvumelana phakathi kwe-RCAs 441-scan line standard esivele isetshenziswa yi-RCAs NBC TV network kanye nesifiso sikaPhilco noDuMont sokukhulisa inani lemigqa yokuskena phakathi kuka-605 no-800 okujwayelekile. Izinga lesikrini izithombe ngomzuzwana owodwa, elihlanganisa imigqa emibili emnyama nomhlophe eyakhelwe kuncomo ka-1936 eyenziwe yi-Radio Manufacturers Association  <response>: ukuguquguquka kwemvamisa FM 