What technological changes have happened to Broadcasting since it began?

Nope..

well the first would be the beginning in 1936 from alexander palace, where the BBC first broadcast.

the next big change was broadcasting from black & white into Colour.which was done experimentally in the late 50's by the BBC after closedown

also the lines on the picture changed also it started out with 405 scanning lines which made up the picture, this was closed down in January 1985 and 625 line were brought in