<prompt> Translate the following text to SwahiliPublic broadcastings big transformation came in the mid-70s, Ledbetter finds, when U.S. corporations stepped in to fill the financial gap for the underfunded network.  <response>: Mabadiliko makubwa ya utangazaji wa umma yalitokea katikati ya miaka ya 1970, wakati mashirika ya Marekani yalipoingilia kati kujaza pengo la kifedha kwa mtandao wa chini wa fedha. 