CCT109H5 Lecture Notes - At&T Corporation, Wireless Telegraphy, Lee De Forest
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Chapter 6 – RADIO
Titanic: Wireless Telegraphy
Italian inventor Marconi created a wireless telegraph that used radio waves
to carry messages in Morse code. He established his company the Marconi
Wireless Telegraph Company, setting up shore-based radio stations to
receive and send telegraph signals to ocean going ships where telegraph
wires can’t reach. The wireless telegraph played a pivotal role in the Titanic
disaster. It helped save the lives of many passengers and this incident got the
attention of the public. The Congress put radio licensing under the
supervision of the Department of Commerce in the Radio Act of 1912.
During WWW1, the US Navy increased radio technology by giving Marconi
exclusive rights to his invention. After a settlement, he set up a new
company called American Telephone & Telegraph (AT &T).
The vacuum tube was invented by Lee De Forest and was used for radio
transmission and reception of sound, voice and music.
O & O – are stations owned and operated by networks.
1996 Telecommunications Act- deregulated radio ownership limits. This
allowed many radio stations to acquire more stations and grow much larger.
These regulations lifted caps on how many stations a group could own.
Podcasting- Internet based radio lies in this feature. It allows people to create
audio programs that can be downloaded onto computers or even directly to
AM- Amplitude modulation
FM- Frequency modulation
Webcast- Internet radio stations use different technologies for ‘streaming’
continuous transmission over the Internet.
Ratings- measure how many people are listening to a station. It breaks down
the audience by key demographics that are important to advertisers so they
know if their ad is reaching the old/young, male or female, Latino or Asian
Chapter Seven – Film & Home Video