[GeronL]

I’ve heard that Hitler made an early TV broadcast, and that is probably the earliest radio signal to depart the earth

Radio was around for decades before TV I think, so probably not the earliest radio signal.

;)

[Tallguy]

Radio was around for decades before TV I think, so probably not the earliest radio signal.

Early broadcast radio was AM. I think AM transmissions just sort of rattle around the ionosphere.