Reply #3: I can attest to the radio broadcasting part

[Canuckistanian]

FM radio was available, technically, in the 1940s.

But because David Sarnof, owner of RCA and HEAVILY invested in the AM format, basically bought FM and threw up so many roadblocks to Edwin Armstrong's invention that he kept it off the air or marginalized until it finally died out in 1949.

Radio and TV are legendary for these series of lawsuits and counter-lawsuits that HELD BACK innovation and progress in the name of the almighty patent protection (and the protection of profits).