TV and Radio By Charli80 Period: Apr 29, 1880 to Apr 29, 2012 Years Apr 29, 1886 Hertz detects eletric waves y Apr 29, 1903 Triode invented Apr 29, 1928 One-way police radio communicatoin Apr 29, 1937 radio have pushbuttons Apr 29, 1946 black and white televisoin in america Apr 29, 1951 colour television in america Apr 29, 1994 internet radio and TV