電子技術(shù)興起與應(yīng)用

1、電子技術(shù)的興起與應(yīng)用人、技術(shù)、經(jīng)濟(jì)、政治、歷史、文化的綜合作用1廣播（broadcasting)的技術(shù)特點(diǎn)無(wú)線廣播和電視的聲音、圖像、文字信號(hào)被加載在電磁波（electro-magnetic wave)上傳播。只要擁有發(fā)射器、電動(dòng)機(jī)和接收裝置，就可以進(jìn)行最簡(jiǎn)單的無(wú)線電信號(hào)的傳播了。電磁波在空氣中以直線向四面八方輻射：地球的地貌和動(dòng)力的限度決定了無(wú)線廣播只能達(dá)到有限的距離。要想向更遠(yuǎn)的距離傳輸信號(hào)，需要其他技術(shù)的幫助（e.g. 微波轉(zhuǎn)播站，電纜，光纜，衛(wèi)星）2廣播（broadcasting)的技術(shù)特點(diǎn)直線傳播的電磁波，尤其是高頻電波，很容易被固體物所阻擋發(fā)射裝置一般都放置在當(dāng)?shù)剌^高的地方。無(wú)線電

2、信號(hào)的傳送需要一定頻率區(qū)間的電磁波，而電磁波的容量是有限的。使用相同或相鄰波段會(huì)產(chǎn)生干擾。對(duì)電磁波的大量需求使其成為稀缺資源，這成為許多國(guó)家對(duì)無(wú)線電使用進(jìn)行立法的基礎(chǔ)。國(guó)家一般都會(huì)規(guī)定不同部門(mén)使用電磁波的波段和合法覆蓋區(qū)域，以防止干擾。國(guó)際間也需要電信協(xié)議來(lái)防止電磁波的跨境干擾。至今無(wú)線電仍舊是最普遍、最經(jīng)濟(jì)、最可靠的遠(yuǎn)距離傳送音像信號(hào)的方式。3Invention of Telegraph: New Era of Communication1844First telegraph line between Washington, D.C., and Baltimore, Maryland1861

3、Lines ran from coast to coast1866The first transatlantic cable ran between Newfoundland and Ireland along the ocean floor.4電報(bào)的局限性不能傳輸人的聲音（Morse Code局限于專業(yè)人員）無(wú)法解決海上船只之間，以及船只與陸地上的通訊（海上運(yùn)輸?shù)陌l(fā)展，現(xiàn)代海戰(zhàn)的需要，商業(yè)與殖民擴(kuò)張）5Development of Wireless Communication19世紀(jì)殖民活動(dòng)和商業(yè)的擴(kuò)張推動(dòng)了交通、通訊技術(shù)的迅速發(fā)展。1860sJames Maxwell (Scottish)

4、 Theorizing electromagnetic phenomenon（從理論上闡釋電磁現(xiàn)象）1880sHeinrich Hertz (German) 實(shí)驗(yàn)證實(shí)了電磁波的存在6Guglielmo Marconi 1894 sending Morse codes over distance 1896 無(wú)線電報(bào)的英國(guó)專利 1897 Marconi Wireless Telegraph Company 1899 Branch opened in US (American Marconi), first wireless Morse code signal across the English

5、Channel to France.1900 First wireless signal across the Atlantic Ocean7De Forest and Radio發(fā)明三極管1901 First case of signal intervention and noise (De Forest Vs. Maconi )1902 Wireless Telephony company (De Forest), direct competition with Marconi1907&1908 Broadcasting experiment 8無(wú)線電技術(shù)發(fā)明早期美國(guó)對(duì)相關(guān)立法的態(tài)度190

6、3：first international conference on wireless communication (signal interference, wireless requirements for ships at sea)1910 US Wireless Ship ActRadio Act of 1912: licensing from the Commerce Department; definition of wireless frequencies as natural resources; formal adoption of SOS Morse-code)9戰(zhàn)爭(zhēng)、國(guó)

7、家戰(zhàn)略、技術(shù)壟斷1914 WWI, issue of national security raised by the navy （GE, AT&T taking advantage over Marconi)1917 美國(guó)參戰(zhàn)，海軍對(duì)無(wú)線電技術(shù)的壟斷和控制1919 國(guó)家擴(kuò)張戰(zhàn)略：保證美國(guó)在無(wú)線電技術(shù)和設(shè)備的國(guó)際壟斷地位（shipping, oil, and communication elements for world power President Wilson）1919 RCA成立, 美國(guó)傳播技術(shù)全球擴(kuò)張的工具10美國(guó)商業(yè)廣播的發(fā)展Early 1920s 商業(yè)廣播實(shí)驗(yàn)迅速發(fā)展，多數(shù)電臺(tái)由

8、大公司建立，但也有許多個(gè)人、教育機(jī)構(gòu)、社會(huì)組織運(yùn)作的非營(yíng)利性電臺(tái)。1922-1924 AT&T, GE, Westinghouse, RCA之間的競(jìng)爭(zhēng) (telephone group Vs. radio group)1925 政府仲裁下的利益重新分配（AT&T monopoly on providing the wires; not to re-enter broadcasting for eight years (actually extended into the mid-1990)Radio Act of 1927，頻率干擾制造的混亂影響了收音機(jī)的銷量，新興工業(yè)的前景受到威脅。27年法

9、案規(guī)定：電臺(tái)不擁有播出頻道，它們只是擁有播出執(zhí)照；電波是公共財(cái)產(chǎn)，廣播機(jī)構(gòu)要從中獲取商業(yè)利益就必須符合公共服務(wù)的規(guī)定（public interest, convenience, or necessity）；成立FRC作為管理廣播的政府機(jī)構(gòu)，廣播執(zhí)照不再由商務(wù)部頒發(fā)。Federal Communication Act of 1934，將FRC改為FCC，其管理權(quán)限涉及廣播、電話、電報(bào)（后來(lái)包括電視、有線服務(wù)和互聯(lián)網(wǎng)）11David Sarnoff 與NBC1926：Creation of NBC NBC-Red (telephone group), NBC-blue (radio group)

10、RCA (50)，GE (30)，Westinghouse (20%).Late 20s：System of affiliate stations gradually establishedEconomic rationales behind the network system 1932：在政府反壟斷壓力下重組, RCA 收購(gòu)了GE、Westinghouse的收音機(jī)生產(chǎn)部門(mén)，以增加這個(gè)領(lǐng)域的競(jìng)爭(zhēng)（mid eighties, GE bought back RCA and NBC）。1941：FCC demanding RCA to sell one of its two networks, a

11、nd NBC-blue became ABC later.Limited frequency space made it difficult for smaller networks to compete with established ones, and the market can only sustain a few national networks.12William Paley與CBS1927： NBC出現(xiàn)競(jìng)爭(zhēng)者 (UIB Columbia Phonograph Company) C(P)BS1928： Paley買(mǎi)下CBS，為父親公司的雪茄作宣傳30s & 40s： Pione

12、er in news programs, soap operas and comedy-variety series, luring talents and stations away from NBC13The Golden Age of Radio(1920s-1950s) Radio sets the precedence for television in America.Weather forecast, farm reports and news analysisVariety shows （綜藝節(jié)目）Live or recorded musicQuiz showsSoap ope

13、ra: Clara, Lu, and Em (1931)Situation comedy: Amos n Andy (1925)Drama serials （系列廣播劇）: War of the Worlds（廣播的形式與內(nèi)容）14早期電視的發(fā)展與實(shí)驗(yàn)1883：Practical system for transmitting image (Paul Nipkow German)1920s： Laboratory improvement of Mechanical television (GE, AT&T, RCA, John L. Baird and Charles Francis Jenk

14、ins)1929：Fifteen experimental television stations in the US 1929: Depression and radios hostility slowed down televisions development, mechanical system not reliable15Development of Electronic Television 1939：New York Worlds Fair first appearance of television, first televised presidential address F

15、ranklin Roosevelts opening speech at the on April 301940: RCA began daily broadcasts to NY area Formation of the National Television System Committee (NTSC) under FCC 16技術(shù)標(biāo)準(zhǔn)的制定對(duì)電視發(fā)展的影響1941: 525-line picture；6MHz of spectrum space, video transmission use AM, audio FM 1942: FCC granting commercial license 1950-1952：Failure of CBS color system, an example of commercial interest blocking the development of technology1953: RCAs color system adopted by FCC to be industrial standard17彩色電視的緩慢發(fā)展1955：Color TV $500; black and white $138 1959: NBC 700 ho