Communications, Electronics and Satellite Chronologyfrom a bit before my time, 500BC to 1970
Written by Godfrey Dykes
© RN Communications Branch Museum/Library
| Solar System | Pythagoras | 500 BC |
| Golden year (nineteen-year astronomical cycle) | Meton | 432 BC |
| Helio-centric (sun centered) universe | Aristarchus (then Copernicus) | Respectively 350BC then 1543 AD |
| Speaking Trumpet | Alexander the Great | 335 BC |
| Oldest written description of data transmission system (alphabet characters represented by code of up to five torch positions on two walls) | Polybius | 300BC |
| Length of tropical year (accuracy 12 seconds) | Hipparchus | 145BC |
| Julian Calendar (prepared for Julius Ceasar) | Sosigenes | 45BC |
| Decimal notation | India | 900 |
| Magnetic compass (used 24 points, reckoned from south) | China | 12th century |
| Rockets in warfare | China | 1232 |
| Decimal notation introduced to Britain | - | 1253 |
| Difference between geographic and magnetic north pole | Columbus | 1492 |
| Helio-centric (sun centered) universe | Copernicus (after Aristarchus) | 1543 |
| Mercator's map projection (Latinised form of name) | Kremer | 1560 |
| Calendar reform (not adopted by England until 1752) | Gregory | 1582 |
| Static electric forces described | Gilbert | 1600 |
| Telescope | Galileo | 1608 |
| First law - elliptical orbit | Kepler | 1609 |
| Second law - constant angular momentum (i.e., equal swept areas in orbital plane in equal time periods) | Kepler | 1609 |
| Third law - (orbital period)² (semi-major axis)³ | Kepler | 1618 |
| Calculating machine | Pascal | 1642 |
| Law of universal gravitation | Newton | 1666 |
| Semaphore with telescope | Hooke | 1684 |
| First law - inertia (Galileo's law of inertia). Second law - force, mass and acceleration. Third law - direct reaction | Newton | 1687 |
| Possibility of artificial earth satellite | Newton | 1687 |
| Insulated electrical lines | von Guericke | 1720 |
| Marine chronometer | Lloyd | 1735 |
| Gyroscope | Setson | 1744 |
| Capacitor (known as Leyden phial or jar) | Musschenbroek | 1746 |
| Electric conduction | Grey | 1720 |
| Electricity propagated by wire {3km) | Watson | 1747 |
| Gregorian calendar adopted by England | - | 1752 |
| 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 |
| Semaphore with mechanical arms | Chappe | 1794 |
| Six shutter optical telegraph | Murray | 1795 |
| Gravitational constant, G | Cavendish | 1797 |
| Electrolysis | Pearson | 1797 |
| Negative numbers | India | 1797 |
| Primary electric cell (silver zinc) | Volta | 1800 |
| Cloud formation classification | Howard | 1803 |
| Arc light | Davy | 1808 |
| Electro chemical telegraph {decomposed water - one line and electrode per character) | Soemmering | 1809 |
| Mechanical computing "engine" | Babbage | 1812 |
| Electro magnetism | Oersted | 1819 |
| Light as "waves" | Fresnel | 1820 |
| Magnetisation of soft iron | Arago and Faraday | 1820 |
| Multi turn coil as electro magnet "multiplier" | Schweigger | 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 |
| Transformer (induction coil) | Faraday | 1831 |
| Commercial electric telegraph | Gauss and Weber | 1833 |
| Rectifier - asymmetric electric conduction | Munk | 1834 |
| Refrigeration | Perkins | 1834 |
| 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 |
| Frequency effects of relative motion (light from stars) | Doeppler | 1843 |
| Electromagnetic telegraph | Morse and Vail | 1844 |
| Incandescent lamp (carbon in vacuum) | Starr | 1845 |
| Telegraph printing roman characters instead of code | House | 1846 |
| Automatic telegraph transmitter | Bain and Wheatstone | 1846 |
| Gutta percha for submarine cables | Faraday | 1849 |
| 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 |
| Fundamental system of electrical and magnetic measurements | Weber | 1851 |
| Duplex telegraphy | Gintl | 1853 |
| Microphone | Bourseul | 1854 |
| Transient response of a transmission line | Kelvin | 1855 |
| Electric lighthouse illumination (South Foreland) - arc with clockwork spacing control | Foucault-Dubosq | 1858 |
| 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 |
| Angstrom unit of length | Angstroem | 1868 |
| Gyro stabiliser | Watt - Boulton | 1868 |
| Navigational satellite proposal {a novel) | Hale | 1869 |
| 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 |
| Vacuum carbon filament dockyard lamps | Lodyguine | 1874 |
| First parallel connection of electric lamps (42 arcs) | Farmer | 1875 |
| Multiplex telegraphy (t.d.m.) five unit code | Baudot | 1875 |
| Sidebands demonstrated in acoustics | Mayer | 1875 |
| Electro magnetic microphone - moving iron | Bell | 1876 |
| Carbon microphone | Edison | 1877 |
| Dynamic microphone - moving coil | Cuttris USA. Siemens Germany, then Wente | 1877 1931 |
| Magneto telephone exchange with drop indicators (New Haven Connecticut) | Jones | 1878 |
| Laser | Bell and Tainer then Townes and Schawlow |
1878 1958 |
| First telephone exchange switchboard in Britain | - | 1879 |
| 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 |
| Radar | Hertz then Watson-Watt) |
1888 1937 |
| Ratchet-and-pawl telephone selector | Strowger | 1889 |
| 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 |
| Coherer detector | Branley | 1892 |
| Revised five unit telegraph alphabet (now called ITA No 2. | Murray | 1895 |
| Cathode ray tube | Crookes | 1895 |
| X-rays (discovered from c.r.t. experiments) | Roentgen | 1895 |
| Wireless telegraphy ship to ship | Jackson | 1895 |
| Commercial common-battery telephone exchange - Worcester Massachusetts | - | 1896 |
| Automatic telephone exchange Augusta New York | - | 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 |
| Telephone line repeaters | Lyons | 1900 |
| 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 |
| Multi stage rocket theory defined | Tsiolkovsky | 1903 |
| Time division multiplex speech | Miner | 1903 |
| Arc transmitter with frequency shift keying (f.s.k.) | Poulsen | 1903 |
| Two electrode vacuum tube rectifier | Fleming | 1904 |
| Directional antennae | Marconi | 1905 |
| Quenched spark transmitter | Wien | 1906 |
| C.W. Oscillations | Poulsen | 1906 |
| 320 km radio telephony | Fessenden | 1906 |
| High frequency alternators | Alexanderson | 1907 |
| Triode amplifier valve (called "audion") | de Forest | 1907 |
| Cathode ray oscillograph | Ryan | 1911 |
| Crystal microphone (led to ASDIC) | Langevin | 1914-1918 |
| 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 |
| Maser | Einstein then Gordon, Zerger and Thomas |
1917 1954 |
| 'Relay' automatic exchange telephone co-ordinate selector | Betulander | 1917 |
| 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 |
| Liquid propellant rocket | Goddard | 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 |
| Cosmic noise discovered | Jansky | 1932 |
| FM 104km New York to Westhampton on 41 MHz | Armstrong | 1933 |
| FM feedback demodulator | Chaffee | 1933 |
| Experimental crossbar telephone exchange Ericsson | (Sweden) | 1933 |
| Klystron | Varian | 1934 |
| Negative feedback amplifier (called inverse feedback | Black | 1934 |
| 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 |
| Radar | Watson-Watt | 1937 |
| Gas discharge lamp | - | 1938 |
| Crossbar telephone exchange Bell laboratories | (USA) | 1938 |
| 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 |
| Bell complex-number computer model 1 | Stibitz | 1940 |
| Submerged repeater (Holyhead and Isle of Man) | - | 1943 |
| Havard Mk1 electronic computer (used 3304 electromagnetic relays) | Lake | 1944 |
| Multi stage combat rocket (Rheinbote) | (Germany) | 1944 |
| 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 |
| Backward-wave-oscillator or carcinotron | (France) | 1952 |
| Cyclic binary code (e.g., for shaft encoders) | Gray | 1953 |
| Maser | Gordon Zerger and Townes | 1954 |
| 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 |
| Tunnel diode | Esaki | 1957 |
| Low noise microwave amplifier (synthetic ruby maser cooled to 2 Kelvins) | Bloembergen | 1957 |
| Artificial earth satellite SPUTNIK 1 (84kg, perigee 230km, apogee 950km) | (USSR) | 1957 |
| Laser (known then as 'optical maser' | Townes and Schawlow | 1958 |
| 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 |
| Navigation satellite TRANSIT 1B | (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 |