Communications, Electronics and Satellites Chronology
Historic events relevant to the W/T branch 1687-1969
| Possibility of artificial earth satellite | Newton | 1687 |
| Insulated electrical lines | von Guericke | 1720 |
| Capacitor [known as Leyden phial or jar] | Musschenbroek | 1746 |
| Electric conduction | Grey | 1720 |
| Electricity propagated by wire [3km] | Watson | 1747 |
| Static electric telegraph [24 lines to 24 pitch-ball electrometres] | Lesage | 1774 |
| Single line static electric telegraph | Lomond | 1787 |
| Pulse position modulation [timed sparks at end of line] | Chappe | 1790 |
| Primary electric cell [silver zinc] | Volta | 1800 |
| Electro chemical telegraph [decomposed water - one line and electrode per character] | Soemmering | 1809 |
| Electro magnetism | Oersted | 1819 |
| Light as "waves" | Fresnel | 1820 |
| Magnetised needle telegraph [one needle per character] | Ampre | 1820 |
| Single magnetic needle telegraph [coded characters -up to four serial digits per character] | Schiling | 1825 |
| Commercial electric telegraph | Gauss and Weber | 1833 |
| Five needle parallel coded telegraph | Wheatstone and Cooke | 1837 |
| Telegraph using signal relay at distant end to key fresh power source | Davy | 1838 |
| HF oscillations observed at a distance | Henry | 1840 |
| Electromagnetic telegraph | Morse and Vail | 1844 |
| Telegraph printing roman characters instead of code | House | 1846 |
| Automatic telegraph transmitter | Bain and Wheatstone | 1846 |
| Submarine telegraph cable [Connecticut River] | - | 1849 |
| Speaking tube | Wishaw | 1850 |
| Submarine telegraph single wire cable Dover to Calais [operated only one day] | Brett | 1850 |
| Submarine telegraph cable Dover to Calais [permanent - four, separated insulated wires] | - | 1851 |
| Duplex telegraphy | Gintl | 1853 |
| Microphone | Bourseul | 1854 |
| Transient response of a transmission line | Kelvin | 1855 |
| Telegraph polarised relay | Siemens | 1858 |
| Submarine telegraph, Ireland to USA 2630 km [initial cable only lasted for 700 messages] | Field | 1858 |
| Rubber insulation for cables | Hooper | 1859 |
| Submarine telegraph, transatlantic permanent [25 words per minute Morse code] | - | 1866 |
| British telegraph installations taken over by Post Office | - | 1870 |
| Multiplex telegraphy [f.d.m.] - morse code, mechanical resonance | Bell | 1870/1874 |
| Telephone | Bell | 1872 |
| 500 b/s data transmission system | Edison | 1874 |
| Multiplex telegraphy [t.d.m.] five unit code | Baudot | 1875 |
| Electro magnetic microphone - moving iron | Bell | 1876 |
| Carbon microphone | Edison | 1877 |
| Dynamic microphone - moving coil | Cuttris USA. Siemens Germany, then Wente | 1877 1931 |
| Piezo-electric effect | Curie | 1880 |
| Condenser microphone | Dolbear then Wente |
1881 1917 |
| Thermionic emission | Edison | 1883 |
| Spark transmitter | Hertz | 1886 |
| Frequency division multiplex speech using mechanical resonance | Leblanc | 1886 |
| Parametric oscillation | Rayleigh | 1887 |
| Wireless telegraph [morse code] | Lodge | 1887 |
| Equalised line | Heaviside | 1887 |
| Metallic valve filaments [platinum] | Fleming | 1890 |
| Submarine four core telephone cable Dover to Calais | - | 1891 |
| Standard primary cell - mercury-cadmium | Weston | 1892 |
| Electrical resonance and f.d.m. telephone system | Autin and Leblance | 1892 |
| Revised five unit telegraph alphabet [now called ITA No 2. | Murray | 1895 |
| Wireless telegraphy ship to ship | Jackson | 1895 |
| Commercial common-battery telephone exchange - Worcester Massachusetts | - | 1896 |
| Quarter wave antenna | Marconi | 1896 |
| Frequency tuning [called syntonic wireless] | Lodge | 1897 |
| Rectifier as a.m. detector | Pupin | 1898 |
| Coupling circuits | Braun | 1898 |
| Radio controlled model boat | Tesla | 1898 |
| Wireless telegraphy across English Channel | Marconi | 1899 |
| Thermionic emission consisting of electrons | Thomson | 1899 |
| Magnetic tape recording | Poulsen | 1899 |
| Radio telephony [2km with 10 kHz rotary spark gap] | Fessenden | 1900 |
| Amplitude modulated radio | Fessenden | 1901 |
| Wireless telegraphy Cornwall to Newfoundland | [Receiver at St John-Marconi transmitter at Poldhu-Fleming] | 1901 |
| British telephone systems taken over by Post Office | - | 1901/2 |
| Loaded transmission line [New York to Newark New Jersey] | Pupin | 1902 |
| Upper atmosphere reflection of radio | Heaviside | 1902 |
| Frequency modulation | Ehret then Armstrong |
1902 1924 |
| Time division multiplex speech | Miner | 1903 |
| Arc transmitter with frequency shift keying [f.s.k.] | Poulsen | 1903 |
| Directional antennae | Marconi | 1905 |
| Quenched spark transmitter | Wien | 1906 |
| C.W. Oscillations | Poulsen | 1906 |
| 320 km radio telephony | Fessenden | 1906 |
| Triode amplifier valve [called "audion"] | de Forest | 1907 |
| Transatlantic radio telephony Arlington to Paris [transmitter with many paralleled triodes] | [USA] | 1915 |
| Sidebands in electrical communications | Carson | 1915 |
| Filters | Campbell | 1915 |
| Modulo-2 addition circuits [used for message encryption] | [Great Britain] | 1915 |
| Telephone New York - San Francisco [5200km over open wires] | - | 1915 |
| Condenser microphone | Wente | 1917 |
| FM infinite sidebands and 'Carson's Rule' | Carson | 1922 |
| Ribbon microphone principle | Schottky then Olsen |
1923 1931 |
| FM practical development | Armstrong after Ehret |
1924 1902 |
| Radio facsimile cheque London to New York | Ranger | 1923 |
| Commercial radio facsimile transatlantic | - | 1926 |
| Tetrode [S625 valve] | Round | 1926 |
| Mu-metal used for loading submarine cables [telegraph speed 2500 word per minute instead of 25] | - | 1926 |
| Rugby [UK] HF transmitter | - | 1927 |
| 12 channel f.d.m. 400 word/min telegraph on single line pair [Western Electric] | [USA] | 1929 |
| Superhet receiver | Armstrong | 1930 |
| Improved dynamic [moving coil] microphone | Wente | 1931 |
| Improved ribbon microphone | Olsen | 1931 |
| Underground telephone cables in Britain | - | 1931 |
| Radio telescope | Jansky | 1931 |
| Microwave [20cm] telephone link Dover to Calais [56km] | - | 1931 |
| FM 104km New York to Westhampton on 41 Mhz | Armstrong | 1933 |
| FM feedback demodulator | Chaffee | 1933 |
| Coaxial telephone cable London - Birmingham [4 core, 280 circuit, 0.5 to 2.1 MHz, repeaters every 8 miles] | - | 1937 |
| Parabolic antenna | Reber | 1937 |
| Pulse code modulation | Reeves | 1937 |
| I am born in July [future user of little sparks] | Harry and Dorothy [my parents] | 1938 |
| FSK data link for picture transmission [Antarctic] | Byrd | 1939 |
| Analogue vocoder | Dudley | 1939 |
| Delta modulation | Deloraine | 1945 |
| Synchronous global communication satellite system proposal | Clarke | 1945 |
| Travelling wave tube | Kompfner | 1945 |
| Atomic clock | Libby | 1946 |
| Moon bounce communications | [USA] | 1946 |
| Printed wiring component board | Sargrove | 1947 |
| Transistor | Shockley | 1948 |
| Experimental p.c.m. link of normal telephone quality | Meacham and Peterson | 1948 |
| Companding suggested for p.c.m. links | Reiling | 1948 |
| Bell tropospheric scatter communications ' beyond the horizon' | [USA] | 1952 |
| Low altitude passive communication satellite proposal | Pierce | 1955 |
| Transatlantic telephone cable TAT1 Oban, Scotland to Clarenville Newfoundland 51 repeaters 144 Mhz [ 2 separate single core cables - one go and one return- providing 35 duplex 4khz telephone circuits plus 1 telegraph channel] | - | 1956 |
| Artificial earth satellite SPUTNIK 1 [84kg, perigee 230km, apogee 950km] | [USSR] | 1957 |
| Store-and-forward communications satellite SCORE [3969kg, taped voice and teletype] | [USA] | 1958 |
| VHF ship to shore public radio telephone in Britain | - | 1958 |
| Transatlantic moon bounce communication, Joddrell Bank [with 33m diameter dish 200 Mhz at 1 kW] | [UK] | 1959 |
| Inflated passive communications satellite ECHO 1 [68kg, perigee 1400km, apogee 1800km] | [USA] | 1960 |
| Active, delayed-repeater communications satellite COURIER [227kg, perigee 970km, apogee 1240km, provided 16 duplex high speed teletype circuits] | [USA] | 1960 |
| WOSTOCK manned satellite [4115kg, perigee 175km, apogee 302km] | Gagarin [USSR] | 1961 |
| Spin-stabilised communication satellite TELESTAR for experimental television | [USA] | 1962 |
| Duplex 12-circuit NASA satellite communication telephone experiment RELAY [with redundant transponders] | [USA] | 1962 |
| Synchronous communications satellite SYNCOM | [USA] | 1963 |
| Commercial geostationary communications satellite EARLY BIRD [INTELSAT 1] [240 telephone channels, or 1 TV channel via 2 single-access transponders] | [USA] | 1965 |
| INTELSAT II [240 telephone circuits or 1 TV channel via 1 multiple access transponder] | [USA] | 1969 |
| Military geostationary communications satellite SKYNET [launch USA] | [UK] | 1969 |