Porsche 911

The 997 was nominated for the World Car of the Year award for 2005. The first marketable products in this field have been developed by EnOcean. In addition, the 911 was voted Number 2 on Automobile Magazine's List of the 100 Coolest Cars. The energy necessary for transmission is taken from the environment (push of a button, temperature differences, light, vibrations, etc.). In 2004, Sports Car International named the 911 number three on the list of Top Sports Cars of the 1960s, the Carrera RS number seven on the list of Top Sports Cars of the 1970s, and the 911 Carrera number seven on the list of Top Sports Cars of the 1980s. in the frame of the ZigBee alliance. ... Energy autarkic radio technology has already been applied in the field of interconnection of different devices, too, e.g.

This won the prestigious Paris-Dakar Rally of 1986.). A novel development of radio technology has been enabled by extremely power-saving miniaturization: battery-less and wireless radio sensors and switches. (In the 1980s Porsche developed the Porsche 959, a four-wheel-drive twin-turbo development of the 911 to compete in the FIA's Group B category. Radio-frequency energy generated for heating of objects is generally not intended to radiate outside of the generating equipment, to prevent interferance with other radio signals. (The Porsche 953, sometimes called the 911 Carrera 4x4, used the 4x4 drivetrain of the 959, which was still being developed.). There are a number of uses of radio:. Here are a few of its more significant rallying achievements. For more, see radio programming.

The rear engine means that the car has inherently good traction. Radio was unique among dramatic presentation that it used only sound. The Porsche 911 showed great promise in rallying from the start. Before the advent of television, commercial radio broadcasts included not only news and music, but dramas, comedies, variety shows, and many other forms of entertainment. Previous Porsche press releases said that for the 911 they would never deviate from the flat-6 rear engine rear drive platform although apparently there are some Porsche engineers who would like a mid-engined platform for future 911s. Read more about radio's history. This is just a rumour, and a very doubtful one at that. Today, radio takes many forms, including wireless networks, mobile communications of all types, as well as radio broadcasting.

The 998 is rumoured to have an entirely new 3.8 litre or 4.0 litre flat eight engine, still hanging over the rear axle. Another use of radio in the pre-war years was the development of detecting and locating aircraft and ships by the use of radar (RAdio Detection And Ranging). Porsche is expected to debut its next entirely new 911, the Type 998, in 2009. Besides broadcasting, point-to-point broadcasting, including telephone messages and relays of radio programs, became widespread in the 1920s and 1930s. It's 0-60 acceleration for the Carrera S was noted to be as fast as 3.9 seconds, in a recent Motor Trend comparison. Broadcasting began to become feasible in the 1920s, with the widespread introduction of radio receivers, particularly in Europe and the United States. Type 997 versions of the GT2 and GT3 have yet to enter production (as of December, 2005). The United States passed on President Woodrow Wilson's Fourteen Points to Germany via radio during the war.

The 997 shares about 30% of its parts with the outgoing 996, but is still technically very similar to it. Radio was used to pass on orders and communications between armies and navies on both sides in World War I; Germany used radio communications for diplomatic messages once its submarine cables were cut by the British. It's interior is also similarly revised, with strong links to older 911 interiors while at the same time looking fresh and modern. One of the most memorable uses of marine telegraphy was during the sinking of the RMS Titanic in 1912, including communications between operators on the sinking ship and nearby vessels, and communications to shore stations listing the survivors. In addition, the new front fascia is reminiscant of the older generation "bug eye" headlights. One of the earliest users included the Japanese Navy scouting the Russian fleet during the Battle of Tsushima in 1905. The 997 keeps the basic profile of the 996, bringing the drag coefficient down to 0.28, but draws on the 993 for detailing. Many of radio's early uses were maritime, for sending telegraphic messages using Morse code between ships and land.

Porsche debuted the 996's replacement, the Type 997, in July 2004. Developments in the latter half of the 20th century (1960-1999):. The Turbo, four-wheel-drive and twin-turbo, often made appearances in magazines' lists of the best cars on sale. Developments in the early 20th century (1900-1959):. The Type 996 spawned over a dozen variations, including all wheel drive Carrera 4 and Carrera 4S models, the club racing-oriented GT3, and the forced-induction 996 Turbo and GT2. The world's first regular wireless broadcasts for entertainment commenced in 1922 from the Marconi Research Centre at Writtle near Chelmsford, England. The Type 996 underwent revisions in late 2002, receiving revised headlamps (now differentiating it from the Boxster), a revised front fascia and an increase in both displacement and power to 3.6 litres and 320 PS (235 kW). The world's first radio news program was broadcast August 31, 1920 by station 8MK in Detroit, Michigan.

The interior was further criticized for its plainness and its lack of relationship to prior 911 interiors, although this came largely from owners of older 911s. Ships at sea heard a broadcast that included Fessenden playing O Holy Night on the violin and reading a passage from the Bible. Otherwise, the Pinky Lai-penned shape followed the original Butzi Porsche design very closely. On Christmas Eve, 1906, Reginald Fessenden (using his heterodyne principle) transmitted the first radio audio broadcast in history from Brant Rock, Massachusetts. The 996 had been on the drawing board first and was a more advanced car in some respects, but the cost-cutting seemed inappropriate for an expensive car. The next great invention was the vacuum tube detector, invented by a team of Westinghouse engineers. Pundits criticized the 996's styling a great deal, largely because it shared its headlamps—indeed much of its front end, mechanically—with the less expensive Boxster. Tesla claimed that Wardenclyffe, as part of a World System of transmitters, would have allowed secure multichannel transceiving of information, universal navigation, time synchronization, and a global location system.

Suspension was by MacPherson struts at the front, as before, with a new coil-sprung multilink system at the rear. Various theories exist on how Tesla intended to achieve the goals of this wireless system (reportedly, a 200 kW system). Its mechanical layout stayed the same however, with the six-cylinder boxer engine mounted longitudinally beyond the rear axle. By 1903, the tower structure neared completion. The 996 became the first 911 in the model's history to utilize an entirely water-cooled engine, an all-new unit of 3.4 litres, developing 296 PS (218 kW). Around 1900, Tesla opened the Wardenclyffe Tower facility and advertised services. The new shape and flush glass bring the drag coefficient down to 0.30. Marconi opened the world's first "wireless" factory in Hall Street, Chelmsford, England in 1898, employing around 50 people.

An all-new bodyshell offered a dramatic 45% increase in torsional rigidity over the 993. government to avoid having to pay damages that were being claimed by the Marconi Company for use of its patents during World War I. For the first time in the evolution of the 911 the car shared no major mechanical components with its predecessor. Some believe the decision was also made for financial reasons, to allow the U.S. The Type 996, introduced as a 1999 model, was a major leap for Porsche. This decision was based on the fact that prior art existed before the establishment of Marconi's patent. The Targa and wide-body versions remained in production in model year 1998, when the entirely new Porsche 996 was launched, the 993´s ultimate successor. Supreme Court, shortly after his death.

The 993 was the last 911 family model to feature an air-cooled engine and the classic silhouette of the 911. However, Tesla's patent (number 645576) was reinstated in 1943 by the U.S. The Targa open-topped model also made a return, this time with a large glass roof that slid under the rear window. In 1909, Marconi, with Karl Ferdinand Braun, was also awarded the Nobel Prize in Physics for "contributions to the development of wireless telegraphy". Non-turbo models appeared that used the Turbo's wide bodyshell and some other components (the Carrera 4S and later the Carrera S). government to avoid having to pay the royalties that were being claimed by Tesla for use of his patents. 63). Some believe this was made for financial reasons, allowing the U.S.

Car and Driver, July 1997, p. Patent Office reversed its decision in 1904, awarding Marconi a patent for the invention of radio, possibly influenced by Marconi's financial backers in the States, who included Thomas Edison and Andrew Carnegie. The similarity in specification and in performance levels inspired several comparison road tests with the Porsche 959 (f.e. The U.S. The turbo version became the first standard production Porsche with twin turbochargers and the first 911 Turbo equipped with all-wheel-drive (in order to delete the 4WD, one had to refer to the turbocharged GT2). The same year in the U.S., some key developments in radio's early history were created and patented by Tesla. The RS version had rear-wheel drive only. In 1897 he established the world's first radio station on the Isle of Wight, England.

A lightweight RS version saw capacity rise to 3.8 litres, with power reaching 300 PS (221 kW). In 1896 Marconi was awarded what is sometimes recognised as the world's first patent for radio with British Patent 12039, Improvements in transmitting electrical impulses and signals and in apparatus there-for. A new four-wheel-drive made a return as an option. The commercial development of wireless technology was thus left for Guglielmo Marconi. Engine capacity remained at 3.6 litres, but power rose to 272 PS (200 kW) thanks to better engine management and exhaust design, and beginning with model year 1996 to 285 PS (210 kW). Thomson quickly realised that Rutherford was a researcher of exceptional ability and invited him to join in a study of the electrical conduction of gases. Chassis refinements enabled the car to keep up dynamically with the competition. Sensing fame and fortune, Rutherford increased the sensitivity of his apparatus until he could detect electromagnetic waves over a distance of several hundred metres.

Mechanically and structurally it is an evolution of the previous car, having the same roof and front bonnet and many mechanical components. Rutherford was encouraged in his work by Sir Robert Ball, who had been scientific adviser to the body maintaining lighthouses on the Irish coastline; he wished to solve the difficult problem of a ship’s inability to detect a lighthouse in fog. The redesign was widely seen as highly successful, and compares for elegance with the models of the early 1970s before the impact-absorbing bumpers disturbed the design. He arrived in England with a reputation as an innovator and inventor, and distinguished himself in several fields, initially by divining the electrical properties of solids and then using wireless waves as a method of signalling. Styling was by Englishman Tony Hatter under the supervision of design chief Harm Lagaay. In 1895 he was awarded an Exhibition of 1851 Science Research Scholarship to Cambridge. The bodywork was smoother, having a noticeably more aerodynamic front end somewhat reminiscent of the Porsche 959. The New Zealander Ernest Rutherford, 1st Baron Rutherford of Nelson was instrumental in the development of radio.

The 964 was replaced in late 1994 by the Type 993. [5] In November 1894, Bose ignited gunpowder and rang a bell at a distance using electromagnetic waves, confirming that communication signals could be sent without using wires, but he too was not interested in patenting his work. Appeals from American customers resulted in Porsche developing the RS America of which 278 were built. Between 1894 and 1900 the Indian physicist Jagdish Chandra Bose performed pioneering research on radio waves and created waves as short as 5 mm. In 1992, Porsche re-introduced a limited-edition RS model, inspired by the 1973 Carrera RS and emissions-legal in Europe only. In March 1896, he transmitted radio waves between different campus buildings in Saint Petersburg, but did not bother to apply for a patent. The 964 was one of the first cars in the world offered with dual airbags standard (from 1991). In 1894 he built a coherer and presented it to the Russian Physical and Chemical Society on May 7, 1895 [4].

Porsche introduced the ahead-of-its-time 'Tiptronic' automatic transmission in the 964 Carrera 2, featuring adaptive electronic management and full manual control. Alexander Popov, who was the first to develop a practical communication system based on the coherer, is sometimes considered to have been the inventor of radio. It is possible to purchase a 911 Turbo from this generation with AWD. Edouard Branly of France and Popov of Russia later produced improved versions of the coherer. The 964 incarnation of the 911 Turbo returned in 1990 after an absence from the price lists, using a refined 3.3-litre engine of the previous Turbo, but only two years later a turbo engine based in the 3.6 litre engine of the other models was introduced. On 19 August 1894, British physicist Sir Oliver Lodge demonstrated the reception of Morse code signalling using radio waves using a detecting device called a coherer, a tube filled with iron filings which had been invented by Temistocle Calzecchi-Onesti at Fermo in Italy in 1884. The rear-wheel-drive version, the Carrera 2, arrived a year later. Tesla is usually considered the first to apply the mechanism of electrical conduction to wireless practices.

The car was more refined, but thought by some journalists to have lost some purity of the 911's concept. [3]. The engine was increased in size to 3600 cc and developed 250 PS (184 kW). He initially experimented with magnetic receivers, unlike the coherers used by Marconi and other early experimenters. Coil springs, ABS brakes and power steering made their debut. [2] They contained all the elements that were later incorporated into radio systems before the development of the vacuum tube. The chassis was redesigned overall. Addressing the Franklin Institute in Philadelphia and the National Electric Light Association, he described and demonstrated in detail the principles of their work.

A rear spoiler deployed at high speed, preserving the purity of line when the vehicle was at rest. Louis, Missouri, Tesla made devices for his experiments with the electricity. Drag coefficient was down to 0.32. In 1893 in St. It was launched as the Carrera 4, the '4' indicating four-wheel-drive, a decision that surprised many but demonstrated the company's commitment to engineering by reminding buyers that race and rally engineering (of the 959) does affect road cars. Claims have been made that Nathan Stubblefield invented radio before either Tesla or Marconi, but his device seems to have worked by induction transmission rather than radio transmission. This would be a very important car for Porsche, since the world economy was undergoing recession and the company could not rely on its image alone. He did not publicize his achievement until 1900.

In late 1989 (for the 1990 model year) the 911 underwent a major evolution with the introduction of the Type 964. Roberto Landell de Moura, a Brazilian priest and scientist, conducted experiments after 1893 (but at least by 1894). Its engine was allowed to rev higher, and the engine developed a little more power. Patent 129971 on July 30, 1872. It was stripped of electric windows, electric seats, and radio to save a claimed 50 kg in weight. Mahlon Loomis was issued U.S. The Carrera Club Sport from 1987 (340 produced) is highly collectible. It was Heinrich Rudolf Hertz who, between 1886 and 1888, first validated Maxwell's theory through experiment, demonstrating that radio radiation had all the properties of waves (now called Hertzian waves), and discovering that the electromagnetic equations could be reformulated into a partial differential equation called the wave equation.

Limited editions: The 911 Speedster, a low-roof version of the Cabriolet, evocative of the Porsche 356 Speedster of the 1950s, was produced in limited numbers. He demonstrated his discovery to the Royal Society in 1880 but was told it was merely induction. This included a hydraulic clutch for those drivers that did not want a leg workout while driving. Hughes was the first to transmit and receive radio waves when he noticed that his induction balance caused noise in the receiver of his homemade telephone. In 1987, the Carrera got a new and better five-speed gearbox sourced from Getrag, model number G50. In 1878 David E. Buyers eagerly paid the increased prices. The theoretical basis of the propagation of electromagnetic waves was first described in 1873 by James Clerk Maxwell in his paper to the Royal Society A dynamical theory of the electromagnetic field, which followed his work between 1861 and 1865.

The non-Turbo models became available as 'Turbo-look', a style that aped the Turbo with wide wheel-arches and the 'whale-tail', but did not reflect any mechanical changes. In the 1920s, amplifying vacuum tubes revolutionized both radio receivers and transmitters. Power was increased, brakes were better, the fuel injection was upgraded to enhance everyday reliability, and the car was more refined. While some early radios used some type of amplification through electric current or battery, through the mid 1920s the most common type of receiver was the crystal set. It was called simply '911 Carrera', the first time the sporty label had been applied to the basic 911. Early radios ran the entire power of the transmitter through a carbon microphone. In 1984 a new 3.2-litre car replaced the 3.0-litre SC model. The controversy over who invented the radio, with the benefit of hindsight, can be broken down as follows:.

Still critics and reporters agree, these Type 911’s are some of the finest Porsches ever made. The identity of the original inventor of radio, at the time called wireless telegraphy, is contentious. North Americans would have to wait for the replacement 3.2L 911 Carrera in 1984 before seeing any extra horsepower. (The noun 'broadcasting' itself came from an agricultural term, meaning 'scattering seeds'.) The American term was then adopted by other languages in Europe and Asia, although Britain retained the term 'wireless' until the mid-20th century. Those cars (1981-1983 911 SC's) would be massaged to yield 204 bhp @ 5900 rpm from their 2994cc power plants. The word appears in a 1907 article by Lee de Forest, was adopted by the United States Navy in 1912 and became common by the time of the first commercial broadcasts in the United States in the 1920s. In 1979 Porsche made plans to replace the 911 with the 928, but the 911 still sold so much better than the 928, that Porsche revised it's strategy and inject new life into the Type 911 European editions. 'Radio' as a noun is said to have been coined by advertising expert Waldo Warren (White 1944).

Cabriolet versions of the 911 have been offered ever since. The prefix radio- in the sense of wireless transmission is first recorded in the word radioconductor, coined by the French physicist Edouard Branly in 1897 and based on the verb to radiate. But while the Targa was priced to match the regular car, the cabriolet cost significantly more. Originally, radio technology was called 'wireless telegraphy', which was shortened to 'wireless'. To many, this was a much more attractive car than the Targa, the other open-top 911. Although the word 'radio' is used to describe this phenomenon, the transmissions which we know as television, radio, radar, and cell phone are all classed as radio frequency emissions. In late 1982 (débuting as the 1983 model) the first 911 cabriolet went on sale (the first Porsche cabriolet since the 356). This can be transformed into audio or other signals that carry information.

Not only was the car a drop top, but it also featured four-wheel drive. When radio waves pass an electrical conductor, the oscillating electric or magnetic field (depending on the shape of the conductor) induces an alternating current and voltage in the conductor. In 1981 a cabriolet concept car was shown at the Frankfurt motorshow. Electromagnetic radiation travels (propagates) by means of oscillating electromagnetic fields that pass through the air and the vacuum of space equally well, and does not require a medium of transport (such as the aether). The top three options for the Type 911, as this car was known, were all part of the new Sport Group Package (UK) which added the now loved and hated whaletail, the front air dam and the black Fuchs wheels. Since the energy of an individual photon of radio frequency is too low to remove an electron from an atom, radio waves are classified as non-ionizing radiation. Yet, the weight of the extra equipment on these cars was blunting performance compared with what would have been expected from earlier, lighter cars with the same power output. Other types of electromagnetic radiation, with frequencies above the RF range are infrared, visible light, ultraviolet, X-rays and gamma rays.

This engine was a unit fresh from the factory delivering 180 PS (132 kW) that was still capable of substantial extra tuning, compared with the 2.7 which was almost at its limit. Radio frequencies occupy the range from a few tens of hertz to a few hundred gigahertz. All 911 models standardized on the 2994cc engine for the 1978 model year (introduced in late 1977). In radio, this acceleration is caused by an alternating current in an antenna. The SC stands for "Super Carrera". Radio waves are a form of electromagnetic radiation, created whenever a charged object (e.g., an electron) accelerates with a frequency that lies in the radio frequency (RF) portion of the electromagnetic spectrum. For the 964 generation, four-wheel-drive was optional in later models and was standard from the 993 Generation and on, except for the lightweight turbocharged GT2. .

There have been turbocharged variants of each subsequent generation of 911. Radio is the wireless transmission of signals, by modulation of electromagnetic waves with frequencies below those of light. With the 4-speed gearbox the 930 was capable of exceeding 200 km/h in third gear!. Large industrial remote-controlled equipment such as cranes and switching locomotives now usually use digital radio techniques to ensure safety and reliability. Before, the five-speed gearboxes of the naturally-aspirated cars were not strong enough to cope with the torque of the turbo engines. Radio remote control: Use of radio waves to transmit control data to a remote object as in some early forms of guided missile, some early TV remotes and a range of model boats, cars and aeroplanes. Only in its last production year the 930 was equipped with a five-speed gear box. These schemes include, for example, solar power stations in orbit beaming energy down to terrestrial users.

Although these cars could be sold for extraordinary premiums over the standard models, the company's reluctance to invest in research and development of the entire 911 line at that time turned out to be an almost fatal decision not only for the 911, but for the entire company. (See Microwave power transmission). As demand for the Turbo soared in the late 1980s, Porsche introduced novelty variants including a slant-nosed, cabriolet version, while not improving the range mechanically. Wireless energy transfer: A number of schemes have been proposed that transmit power using microwaves, and the technique has been demonstrated. Private teams continued to compete successfully with the car until well into the 1980s. Similar services exist in other parts of the world. The wilder Porsche 935, a more highly tuned car in FIA Group 5 and evolved from the 2.1-litre RSR Turbo of 1974, was campaigned in 1976 by the factory and won Le Mans in 1979. Personal radio services such as Citizens' Band Radio, Family Radio Service, Multi-Use Radio Service and others exist in North America to provide simple, (usually) short range communication for individuals and small groups, without the overhead of licensing.

Many participated at Le Mans and other races including some epic battles with the BMW 3.0 CSL 'Batmobile'. Several forms of radio were pioneered by radio amateurs and later became commercially important, including FM, single-sideband AM, digital packet radio and satellite repeaters. Production figures of the car soon qualified its racing incarnation for FIA Group 4 competition as the Porsche 934, of 1976. Radio amateurs use all forms of encoding, including obsolete and experimental ones. The early cars are known for extreme turbo lag. Radio amateurs are able to use frequencies in a large number of narrow bands throughout the radio spectrum. Starting out with a 3.0-litre engine (260 PS or 191 kW), it rose to 3.3 litres (300 PS or 221 kW) for the 1978 model year. This has been of great use, saving lives in many instances.

The body shape is distinctive thanks to wide wheel-arches to accommodate the wide tyres, and a large rear spoiler often known as a 'whale tail'. They may also provide an emergency and public-service radio service. Although called simply Porsche 911 Turbo in Europe, it was marketed as Porsche 930 (930 being its internal type number) in North America. Amateur radio is a hobby where enthusiasts who purchase or build their own equipment and use radio for their own enjoyment. In 1975 Porsche introduced the first production turbocharged 911. Since the waves are long, the probe could be a very light metal mesh, and thus achieve higher accelerations than if it were a solar sail. Notably, it achieved little success in racing.. Conceptually, spacecraft propulsion: Radiation pressure from intense radio waves has been proposed as a propulsion method for an interstellar probe called Starwisp.

Throughout its 17 years, despite its capabilities on the road, it never outsold the 911. These are enough to perform station-keeping in microgravity environments. The 928 sold reasonably well, and managed to survive from its introduction in 1977 until 1995. Tractor beams: Radio waves exert small electrostatic and magnetic forces. Larger, with a front-mounted V8 engine that was considerably more powerful than the contemporary 911's, the 928 was not only designed to eclipse its performance, it was designed to be a more comfortable car, a sporty grand tourer rather than a focused sports car. Induction furnaces are used for melting metal for casting. Although Porsche was continuing development of the 911, executives were troubled by its declining sales numbers and in 1971 greenlighted work on the Porsche 928. Diathermy equipment is used in surgery for sealing of blood vessels.

In 1976 the Porsche 924 took this car's place for the 1977 "model year" and beyond. The microwave frequencies used are actually about a factor of 10 below the resonant frequency.). In all, 2099 units were produced. (Note: It is a common misconception that the radio waves are tuned to the resonant frequency of water molecules. It used the I-series chassis and the 2.0 Volkswagen engine from the Porsche 914. Microwave ovens use intense radio waves to heat food. market, was the 912E, a 4-cylinder version of the 911 like the old 912 that had last been produced in 1969. Most new radio systems are digital, see also:Digital TV, Satellite Radio, Digital Audio Broadcasting.

Also produced for the 1976 "model year", for the U.S. COFDM is used for WiFi, some cell phones, Digital Radio Mondiale, Eureka 147, and many other local area network, digital TV and radio standards. However, the engine did have increased drivability. An adaptive system, or one that sends error-correction codes can also resist interference, because most interference can affect only a few of the QAM channels. Therefore the 911S's horsepower decreased from 190 to 165 despite the displacement increase from 2.4 to 2.7L. COFDM resists fading and ghosting because the narrow-channel QAM signals can be sent slowly. While this system was exceedingly reliable, it did not allow the use of as "hot" cams as MFI or carburators allowed. Modern COFDM systems use a small computer to make and decode the signal with digital signal processing, which is more flexible and far less expensive than older systems that implemented separate electronic channels.

This system varied fuel pressure to the injectors dependant on the mass airflow. The digital signal is often sent as QAM on the subchannels. In addition with the 1973.5 engines Porsche moved away from MFI to Bosch K-Jetronic CIS. COFDM breaks a digital signal into as many as several hundred slower subchannels. However, the aluminium case weighed 15 lbs more than the magnesium one. Systems that need reliability, or that share their frequency with other services, may use "corrected orthogonal frequency-division multiplexing" or COFDM. The move to that engine across the board was welcome for reliability reasons. A special bit pattern is used to locate the beginning of a frame.

The 3.0-litre engine of the Turbo and Carrera had not used magnesium, but rather aluminium, thereby showing equal expansion rates to the cylinders. Usually the bits are sent in "frames" that repeat. In addition, some engines saw problems whereby the cylinder head studs would pull themselves out of the crankcase. Engineers like QAM because it packs the most bits into a radio signal. The engines saw problems, particularly in hot climates, where the different rates of thermal expansion between the magnesium of the crankcase and the aluminium of the cylinder heads contributed to major failure. QAM sends data by changing both the phase and the amplitude of the radio signal. In effect, the 2.4-litre engine had been enlarged with no additional cooling capacity. Microwave dishes on satellites, telephone exchanges and TV stations usually use quadrature amplitude modulation (QAM).

The 2.7 engines proved to be less reliable than the 'bulletproof' 2.4 units. Aircraft use a 1200 Baud radioteletype service over VHF to send their ID, altitude and position, and get gate and connecting-flight data. In 1976 the Carrera model was upgraded to the Turbo's 2992 cc engine, minus the turbocharger, developing 200 PS (147 kW). These are still used by the military and weather services. The Turbo was introduced in 1975 (see below). From about 1925 to 1975, radio teletype was how most commercial messages were sent to less developed countries. The model line-up was now: 911, 911S and 911 Carrera (the latter now a regular production model). Groups of five or seven bits become a character printed by a teletype.

The interior was refreshed too. They send a bit as one of two tones. The cars looked rather different from the previous year's thanks to bulky new bumpers front and rear, to conform with low-speed impact protection requirements of US law. Radio teletypes usually operate on short-wave (HF) and are much loved by the military because they create written information without a skilled operator. From 1974 a detuned version of the 2687cc engine from the Carrera RS was used in the mainstream production cars. Strictly, on-off keying of a carrier should be known as "Interrupted Continuous Wave" or ICW. The large rear spoiler and the 3.0 turbo engine were to be used again in the production 911 Turbo and the 934 racing car. CW is still used, these days primarily by amateur radio operators (hams).

The turbo car came second at Le Mans in 1974, a significant event in that its engine would form the basis of many future Porsche assaults on sportscar racing, and can be regarded as the start of its commitment to turbocharging. CW uses less than 100Hz of bandwidth. The Carrera RSR 3.0 and Carrera RSR Turbo (its 2.1-litre engine due to a 1.4x equivalency formula) were made in tiny numbers for racing. A receiver with a local oscillator would "heterodyne" with the pure radio frequency, creating a whistle-like audio tone. The 3.0-litre cars used standard-gauge steel, and thanks to that extra 180 kg the extra 20 PS (15 kW) did not give it a performance advantage. The next advance was continuous wave telegraphy, or CW, in which a pure radio frequency, produced by a vacuum tube electronic oscillator was switched on and off by a key. A more powerful version, the Carrera RS 3.0, was also made. This is very wasteful of both radio frequencies and power.

In total 1636 were made, comfortably exceeding the 500 that had to be made to qualify for the vital FIA Group 4 class. Spark gap transmitters are now illegal, because their transmissions span several hundred megahertz. Compared with a standard 911S, the Carrera RS had a larger engine (2687cc) developing 210 PS (154 kW), revised and stiffened suspension, a 'ducktail' rear spoiler, larger brakes, larger wheels & wheel-arches, and was about 150 kg lighter—most of the saving coming from the thin-gauge steel used for the bodyshell. The rotating commutator produced a tone in the receiver, where a simple spark gap would produce a hiss, indistinguishable from static. It was built so that Porsche could enter racing formulae that demanded that a certain minimum number of production cars were made. By pressing the key, the operator could send messages in Morse code by energizing a rotating commutating spark gap. This model, much prized by collectors, is one of the all-time classic 911s. The oldest form of digital broadcast was spark gap telegraphy, used by pioneers such as Marconi.

The cars had success at the Daytona 6 Hours, the Sebring 12 Hours, the Nurburgring 1000 km and the Targa Florio. There are several types, with widely-varying performance. Weight was down to 960 kg. Their purpose is to help rescue people in the first day, when survival is most likely. The cars were available with engines of either 2466cc or 2492cc, producing 270 bhp at 8000 rpm. Emergency position-indicating rescue beacons (EPIRBs), emergency locating transmitters or personal locator beacons are small radio transmitters that satellites can use to locate a person or vehicle needing rescue. For racing at this time, the 911 ST was made in tiny numbers. Some weather radar use the doppler to measure wind speeds.

With the car's weight only 2314 lb (1050 kg), these are often regarded as the best classic mainstream 911s. Weather radars resemble search radars, but use radio waves with circular polarization and a wavelength to reflect from water droplets. These cars also gained a discreet spoiler under the front bumper to help high-speed stability. Targeting radars use the same principle as search radar but scan a much smaller area far more often, usually several times a second or more. 1972 911s are now one of the most desirable early 911s because of this feature. Sometimes search radars use the doppler effect to separate moving vehicles from clutter. Unfortunately, this unique design was scrapped after only one year, some say because inattentive gas station attendants were putting gas in the oil tank! The oil tank was moved back to its original position for the 1973 model year, and there is stayed until it was moved back within the wheelbase for the 964 models. They usually scan the area two to four times a minute.

To facilitate filling of the oil tank, Porsche installed an oil filler door (much like the fuel filler door on the left front fender) on the right rear quarter panel. Search radars scan a wide area with pulses of short radio waves. This had the effect of moving the weight of almost 9 quarts of oil from outside the wheelbase to inside, improving the handling. Some can superimpose sonar data and map data from GPS position. The biggest thing Porsche did was relocate the oil tank from its position behind the right rear wheel to in front of it. The best general-purpose radars distinguish the rain of heavy storms, as well as land and vehicles. In 1972 tremendous effort was made to improve the handling of the 911. General purpose radars generally use navigational radar frequencies, but modulate and polarize the pulse so the receiver can determine the type of surface of the reflector.

The Sportomatic transmission was still available, but only as a special order. They are common on commercial ships and long-distance commercial aircraft. Some say this was because the dog-leg shift to first was inconvenient for in town driving, other say it was due to Porsche’s desire to put 5th gear outside the main transmission housing where it could easily be changed for different races. They use very short waves that reflect from earth and stone. Derived from the transmission in the Porsche 908 race car, the 915 did away with the 901/911 transmission's 'dog-leg' style first gear arrangement, opting for a traditional H pattern with first gear up to the left, second gear underneath first, etc. Navigational radars scan a wide area two to four times per minute. With the power and torque increases, the 2.4 L cars also got a newer, stronger transmission, identified by its Porsche type number 915. The polarization and frequency of the return can sense the type of surface.

These cars are commonly referred to as 1973.5 models. The direction of the beam determines the direction of the reflection. In January, 1973, US 911Ts were switched to the new K-Jetronic CIS (Continuous Fuel Injection) system from Bosch. The delay caused by the echo measures the distance. 911T also used MFI, while the RoW (rest-of-the-world) 911T was carbureted, which accounts for the 10 hp (7.5 kW) power difference between the two. Radar detects things at a distance by bouncing radio waves off them. The U.S. In some cases they used marine radiolocation beacons, which share a range of frequencies just above AM radio with amateur radio operators.

The 911E and 911S used mechanical fuel injection (MFI) in all markets. Before 1960 navigators used movable loop antennas to locate commercial AM stations near cities. The new power ratings were 130 hp (97 kW), or 140 hp (104 kW) in the U.S., for the T, 165 hp (123 kW) for the E and 190 hp (142 kW) for the S. Radio direction-finding is the oldest form of radio navigation. This is universally known as the "2.4 L" engine, despite its displacement being closer to 2.3 litres — perhaps to emphasize the increase over the 2.2. An aircraft can get readings from two VORs, and locate its position at the intersection of the two beams. However, all models got a new, larger 2341 cc/142 in³ engine. By measuring the difference in phase of these two signals, an aircraft can determine its bearing from the station.

The 1972-1973 model years consisted of the same models of 911—the entry level T, the midrange E and the top of the line S. When the directional signal is facing north, an omnidirectional signal pulses. Despite the lower power output of the 911E (155PS) compared to the 911S (180PS) the 911E was quicker in acceleration up to 100 mph (160kmh). A directional signal rotates like a lighthouse at a fixed rate. The 2.2 litre 911E was called "The secret weapon from Zuffenhausen". VOR systems (used by aircraft), have an antenna array that transmits two signals simultaneously. The 912 was discontinued, thanks to the introduction of the Porsche 914 as an entry model. Loran systems also used time-of-flight radio signals, but from radio stations on the ground.

Power outputs were uprated to 125 (911T), 155 (911E) and 180 PS (911S). A computer in the receiver does the math. For the 1970 model year the engines of all 911s was increased to 2195 cc. The receiver listens to four satellites, and can figure its position as being on a line that is tangent to a spherical shell around each satellite, determined by the time-of-flight of the radio signals from the satellite. A controversial semi-automatic Sportomatic [1] model, composed of a torque converter, an automatic clutch, and the four speed transmission, was added to the product lineup. The satellite transmits its position, and the time of the transmission. Fuel injection arrived for the 911S and for a new middle model, 911E. All satellite navigation systems use satellites with precision clocks.

The overall length of the car did not change: rather, the rear wheels were relocated aft. With all this, it takes only half the bandwidth of an analog TV signal because the video data is compressed. In 1968 the B series was introduced: the wheelbase for all 911 and 912 models was increased from 2211 mm to 2268 mm, an effective remedy to the car's nervous handling at the limit. Although any data could be sent, the standard is to use MPEG-2 for video, and five CD-quality (44.1 kHz) audio channels (center, left, right, left-back and right back). This was a lightweight racing version with thin aluminium doors, a magnesium crankcase, twin-spark cylinder heads, and a power output of 210 PS (154 kW). A Reed-Solomon error correction code lets the receiver detect and correct errors in the data. More excitingly, the 911R was produced in tiny numbers (20 in all). The bits are sent out-of-order to reduce the effect of bursts of radio noise.

The staple 130 PS (96 kW) model was renamed the 911L. Digital television encodes three bits as eight strengths of AM signal. The 110 PS (81 kW) 911T was also launched in 1967 and effectively replaced the 912. Television sends the picture as AM, and the sound as FM, on the same radio signal. (Porsche had, at one point, thought that the NHTSA would outlaw fully open convertibles in the US, an important market for the 911, and introduced the Targa as a 'stop gap' model.) The name 'Targa' came from the Targa Florio road race in Sicily, in which Porsche had notable success: victories in 1956, 1959, 1960, 1963, 1964, 1966, 1967, 1968, 1969, 1970 and 1973. Iridium provides cell phones, except the cells are satellites in orbit. The Targa had a removable roof panel, a removable plastic rear window (although this was soon replaced by a fixed glass item) and a stainless steel roll bar. INMARSAT uses geosynchronous satellites, with aimed high-gain antennas on the vehicles.

In 1967 the Targa version was introduced. Both types provide world-wide coverage. In motorsport at the same time, installed in the mid-engined Porsche 904 and Porsche 906, the engine was developed to 210 PS (154 kW). Satellite phones come in two types: INMARSAT and Iridium. Alloy wheels from Fuchs, in a distinctive 5-leaf design, were offered for the first time. Cell phones originally used FM, but now most use various digital encodings. In 1966 Porsche introduced the more powerful 911S, the engine's power raised to 160 PS (118 kW). When the phone leaves the cell radio's area, the central computer switches the phone to a new cell.

It used the 356's 4-cylinder, 1600cc 90 PS (66 kW) engine but wore the 911 bodywork and was in most respects a 911. Cell phones transmit to a local cell transmitter/receiver site, which connects to the public service telephone network through an optic fiber or microwave radio. The Porsche 912, introduced the same year, served as a direct replacement. Commercial services such as XM and Sirius offer encrypted digital Satellite radio. The 356 came to the end of its life in 1965, but there was still a market for a 4-cylinder car, particularly in the USA. TETRA, Terrestrial Trunked Radio is a digital cell phone system for military, police and ambulances. Erwin Komenda, the leader of the Porsche car body construction department, was also involved in the design. This also makes the transmitter about three times more powerful, because it doesn't need to transmit the unused carrier and sideband.

The styling was largely by Ferdinand "Butzi" Porsche, son of the company founder Ferdinand "Ferry" Porsche. SSB cuts the bandwidth in half by suppressing the carrier and (usually) lower sideband. It was mated to a five speed manual 'Type 901' transmission. Viewed as a graph of frequency versus power, an AM signal shows power where the frequencies of the voice add and subtract with the main radio frequency. The car had four seats although the rear seats are very small, and the car is usually called a 2+2 rather than a four-seater (the 356 was also a 2+2). SSB sounds like ducks quacking on an AM radio. Its 130 PS¹ (96 kW) six-cylinder engine, in the 'boxer' configuration like the 356, air-cooled and rear-mounted, displaced 1991cc compared with the 356's four-cylinder 1600cc unit. Most use single sideband voice (SSB), which uses less bandwidth than AM.

It went on sale in 1964. Civil and military HF (high frequency) voice services use shortwave radio to contact ships at sea, aircraft and isolated settlements. After a legal protest from Peugeot (on the grounds that they owned the trademark to all car names formed by three numbers with a zero in the middle), but before production started, the car had its name changed to 911. Fidelity is sacrificed to use a smaller range of radio frequencies, usually five kilohertz of deviation (5 thousand cycles per second), rather than the 75 used by FM broadcasts and 25 used by TV sound. The car made its public debut as the 'Porsche 901' (901 being its internal project number) at the 1963 Internationale Automobil-Ausstellung, better known to English speakers as the Frankfurt motor show. Government, police, fire and commercial voice services use narrowband FM on special frequencies. The 911 was developed as a more powerful, larger, more comfortable replacement for the Porsche 356, the company's first model, and essentially a sporting evolution of the Volkswagen Beetle. Marine voice radios can use AM in the shortwave High Frequency (HF—3 MHz to 30 MHz) radio spectrum for very long ranges or narrowband FM in the VHF spectrum for much shorter ranges.

The first 911 models are the 'A series', the first 993 cars are the 'R series'.). Aircraft fly high enough that their transmitters can be received hundreds of miles (kilometres) away, even though they are using VHF. It often changes annually to reflect changes for the new model year. (Use of FM would result in stronger stations blocking out reception of weaker stations due to FM's capture effect). A note on designations: the series letter (A, B, C, etc.) is used by Porsche to indicate the revision for production cars. AM is used so that multiple stations on the same channel can be received. . Aviation voice radios use VHF AM.