Broadcast Radio Turns 100

GraWil writes "On Christmas eve 1906, a Canadian physicist named Reginald Fessenden presented the world's first wireless radio broadcast from his transmitter at Brant Rock, MA. The transmission included Christmas music and was heard by radio operators on board US Navy and United Fruit Company ships equipped with Fessenden's wireless receivers at various distances over the South and North Atlantic, and in the West Indies. Fessenden was a key rival of Marconi in the early 1900s who, using morse-code, succeeded in passing signals across the Atlantic in 1901. Fessenden's work was the first real departure from Marconi's damped-wave-coherer system for telegraphy and represent the first pioneering steps toward radio communications and radio broadcasting. He later became embroiled in a long-running legal dispute over the control of his radio-related patents, which were eventually acquired by RCA."

Comments

Thank god the RIAA wasn't around back then.

[aix tom]

They would have killed it off pretty quick.

Re:Super heterodyne?

[NateTech]

Ahh, but KOA doesn't broadcast from the top of a mountain at all. In fact, their tower is located slightly south and east of Centennial Airport in the southern suburbs of Denver. In fact, it's one of the prominent landmarks for finding the APA practice areas for pilots doing training work.

http://en.wikipedia.org/wiki/KOA_(AM)

The key to KOA's monster signal is two-fold:
1. They're a 50KW ND station... 50,000W all day, every day. Standard AM Broadcast physics going on here... at night, the sun goes down and the MUF (maximum usable frequency) goes up, and the F layers of the ionosphere do a great job of bouncing KOA to far-distant places. (They claim on-air 38 states, Canada & Mexico, but DX SWL's report them from far further away fairly reqularly.)

2. They specifically designed the 5/8 wave tower to sit in a (relatively) low-lying area that is slightly "wetter" (to put it simply - there's an underground layer of clay and an aquifer) than the surrounding dry high-plains around Denver. Their "built in" RF ground-plane is therefore much more effective underneath their tower (which is the antenna, like most AM stations) than many others around the area.