The earliest radio stations were simply radiotelegraphy systems and did not carry audio. For audio broadcasts to be possible electronic detection and amplification devices had to be incorporated.
The thermionic valve was invented in 1904 by the English physicist John Ambrose Fleming. He developed a device he called an "oscillation valve" (because it passes current in only one direction). The heated filament, or cathode, was capable of thermionic emission of electrons that would flow to the plate (or anode) when it was at a higher voltage. Electrons, however, could not pass in the reverse direction because the plate was not heated and thus not capable of thermionic emission of electrons. Later known as the Fleming valve, it could be used as a rectifier of alternating current and as a radio wave detector. This greatly improved the crystal set which rectified the radio signal using an early solid-state diode based on a crystal and a so-called cat's whisker. However, what was still required was an amplifier.
The triode (mercury-vapor filled with a control grid) was patented on March 4, 1906 by the Austrian Robert von Lieben independent from that, on October 25, 1906 Lee De Forest patented his three-element Audion. It wasn't put to practical use until 1912, when its amplifying ability became recognized by researchers.
By about 1920, valve technology had matured to the point where radio broadcasting was fast becoming viable. However, an early audio transmission that could be termed a broadcast may have occurred on Christmas Eve in 1906 by Reginald Fessenden, although this is disputed. While many early experimenters attempted to create systems similar to radiotelephone devices by which only two parties were meant to communicate, there were others who intended to transmit to larger audiences. Charles Herrold started broadcasting in California in 1909 and was carrying audio by the next year. (Herrold's station eventually became KCBS).
In The Hague, the Netherlands, PCGG started broadcasting on November 6, 1919, making it, arguably the first commercial broadcasting station. In 1916, Frank Conrad, an employee for the Westinghouse Electric Corporation, began broadcasting from his Wilkinsburg, Pennsylvania garage with the call letters 8XK. Later, the station was moved to the top of the Westinghouse factory building in East Pittsburgh, Pennsylvania. Westinghouse relaunched the station as KDKA on November 2, 1920, as the first commercially licensed radio station in America. The commercial broadcasting designation came from the type of broadcast license; advertisements did not air until years later. The first licensed broadcast in the United States came from KDKA itself: the results of the Harding/Cox Presidential Election. The Montreal station that became CFCF began broadcast programming on May 20, 1920, and the Detroit station that became WWJ began program broadcasts beginning on August 20, 1920, although neither held a license at the time.
American Centurion Radio - 06/29/14 - FPRN Radio by fprnradio
In 1920 wireless broadcasts for entertainment began in the UK from the Marconi Research Centre 2MT at Writtle near Chelmsford, England. A famous broadcast from Marconi's New Street Works factory in Chelmsford was made by the famous soprano Dame Nellie Melba on 15 June 1920, where she sang two arias and her famous trill. She was the first artist of international renown to participate in direct radio broadcasts. The 2MT station began to broadcast regular entertainment in 1922. The BBC was amalgamated in 1922 and received a Royal Charter in 1926, making it the first national broadcaster in the world.
Radio Argentina began regularly scheduled transmissions from the Teatro Coliseo in Buenos Aires on August 27, 1920, making its own priority claim. The station got its license on November 19, 1923. The delay was due to the lack of official Argentine licensing procedures before that date. This station continued regular broadcasting of entertainment and cultural fare for several decades.
Radio in education soon followed and colleges across the U.S. began adding radio broadcasting courses to their curricula. Curry College in Milton, Massachusetts introduced one of the first broadcasting majors in 1932 when the college teamed up with WLOE in Boston to have students broadcast programs.
Failure: prohibition doesn't help. The third major reason that marijuana should be legal is because prohibition does not help the country in any way, and causes a lot of problems. There is no good evidence that prohibition decreases drug use, and there are several theories that suggest prohibition might actually increase drug use (i.e. the "forbidden fruit" effect, and easier accessibility for youth). One unintended effect of marijuana prohibition is that marijuana is very popular in American high schools. Why? Because it is available. You don't have to be 21 to buy marijuana -- marijuana dealers usually don't care how old you are as long as you have money. It is actually easier for many high school students to obtain marijuana than it is for them to obtain alcohol, because alcohol is legal and therefore regulated to keep it away from kids. If our goal is to reduce drug consumption, then we should focus on open and honest programs to educate youth, regulation to keep drugs away from kids, and treatment programs for people with drug problems. But the current prohibition scheme does not allow such reasonable approaches to marijuana; instead we are stuck with 'DARE' police officers spreading lies about drugs in schools, and policies that result in jail time rather than treatment for people with drug problems. We tried prohibition with alcohol, and that failed miserably. We should be able to learn our lesson and stop repeating the same mistake.
Prohibition does not work. Education and treatment are better ways to address the drug problem.
There are plenty of other reasons why marijuana should be legal. Just to name a few: Medicinal use: Marijuana can be used as medicine because it helps to stimulate apetite and relieve nausea in cancer and AIDS patients.
Hemp: The hemp plant is a valuable natural resource. Legalizing marijuana would eliminate the confusion surrounding hemp and allow us to take advantage of hemp's agricultural and industrial uses.
:Religious use: Some religions instruct their followers to use marijuana. Just like Christianity and Judaism instruct their followers to drink wine on certain occaisions, some Hindus, Buddhists, Rastafarians, and members of other religions use marijuana as part of their spiritual and religious ceremonies. These people deserve the freedom to practice their religion as they see fit. The First Amendment to the U.S. Constitution says that the government cannot 'prohibit the free exercise' of religion, and so marijuana should be legal.