RX12874 , also known as the Passive Detection System ( PDS ) and by its nickname " Winkle ", was a radar detector system used as part of the Royal Air Force 's Linesman/Mediator radar network until the early 1980s. Winkle passed out of service along with the rest of the Linesman system as the IUKADGE network replaced it.
104-501: Winkle was developed in the late 1950s to counter the carcinotron , a radar jammer so effective that it was initially believed it would render all long-range radars useless. Winkle used a network of stations to listen for carcinotron broadcasts, and combined the information from them to track the jammer aircraft as effectively as a radar could. The system was based on a series of High Speed Aerial ( HSA ) installations and AMES Type 85 ("Blue Yeoman") radars. Both were used as receivers;
208-470: A turboprop design developed at the Royal Aircraft Establishment (RAE) under the direction of Hayne Constant . It is somewhat ironic that BTH, its erstwhile partners, were at the same time working with Frank Whittle on his pioneering jet designs. In mid-1938, MV was awarded a contract to build Avro Manchester twin-engined heavy bombers under licence from A.V. Roe . As this type of work
312-521: A complete 360 degree scan at 4 RPM, or alternately a sector scan at the same angular speed of 24 degrees per second. This meant the radar and PDS both had the same "data rate". During normal operations, the associated Type 85 was continually scanning. When the Type 85 scanned past a jammer, the jammer signal would briefly reach the correlator. As long as the HSA was pointed in the same general direction it would send
416-471: A correlator for every feed horn, the system used a smaller number arranged in a loop, and as soon as one correlation was complete, its measurement was stored in the computer and then it was used to perform the correlation on the next feed horn. When the scan was complete, this data was sent to a unique "theta-phi" display. The display was drawn by scanning vertically, as opposed to horizontally as in conventional analogue television . Each vertical scan displayed
520-410: A heterodyne local oscillator. The frequency–voltage sensitivity, is given by the relation The oscillation frequency is also sensitive to the beam current (called "frequency pushing"). The current fluctuations at low frequencies are mainly due to the anode voltage supply, and the sensitivity to the anode voltage is given by This sensitivity as compared to the cathode voltage sensitivity, is reduced by
624-589: A hindrance to gaining government contracts during the First World War . In 1917 a holding company was formed to try to find financing to buy the company's properties. In May 1917, control of the holding company was obtained jointly by the Metropolitan Carriage, Wagon and Finance Company , of Birmingham , chaired by Dudley Docker , and Vickers Limited , of Barrow-in-Furness . On 15 March 1919, Docker agreed terms with Vickers, for Vickers to purchase all
728-453: A hole through a rectangular waveguide and shooting the beam through the hole. The waveguide then goes through two right angle turns, forming a C-shape and crossing the beam again. This basic pattern is repeated along the length of the tube so the waveguide passes across the beam several times, forming a series of S-shapes. The original RF signal enters from what would be the far end of the TWT, where
832-509: A magnetic field in any nearby conductor. This allows the now-amplified signal to be extracted. In systems like the magnetron or klystron, this is accomplished with another resonant cavity. In the helical designs, this process occurs along the entire length of the tube, reinforcing the original signal in the helical conductor. The "problem" with traditional designs is that they have relatively narrow bandwidths; designs based on resonators will work with signals within 10% or 20% of their design, as this
936-720: A massive expansion of electrical distribution, installations, and appliance purchases. Sales shot up, and 1927 marked the company's best year to date. On 15 November 1922 the BBC was registered and the BBC's Manchester station, 2ZY , was officially opened on 375 metres transmitting from the Metropolitan Vickers Electricity works in Old Trafford. In 1921, they bought a 9-acre (3.6 ha) site at Attercliffe Common in Sheffield , which
1040-411: A nationwide system known as Improved UKADGE , replacing the entire Linesman system by 1984. The High Speed Aerial (HSA) was designed to have partial vertical focussing to allow it to scan to high elevation angles. During normal reception, a series of feed horns allowed signals from anywhere across the front of the antenna to be received in a pattern that was about 70 degrees wide. This lack of focusing
1144-441: A normal radar return, distinguished only by its small circle icon instead of a single dot. Operators could decrease the Type 85 receiver sensitivity while the radar passed that location, so that the jamming did not obscure the display at nearby angles. Combined with identification friend or foe (IFF) signals, this allowed a fighter aircraft 's signal to remain visible and interceptions could proceed as normal. In 1950, engineers at
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#17330856184001248-579: A number of turbines built by the company in and for the Soviet Union proved to be faulty. The British government intervened; the engineers were released and trade with Russia was resumed after a brief embargo. During the 1930s Metropolitan Vickers produced two dozen very large diameter (3m/10 ft) three-phase AC traction motors for the Hungarian railway's V40 and V60 electric locomotives. The 1640 kW rated power machinery, designed by Kálmán Kandó ,
1352-748: A place in history as the builders of the first commercial transistor computer , the Metrovick 950 , and the first British axial-flow jet engine , the Metropolitan-Vickers F.2 . Its factory in Trafford Park , Manchester , was for most of the 20th century one of the biggest and most important heavy engineering facilities in Britain and the world. Metrovick started as a way to separate the existing British Westinghouse Electrical and Manufacturing Company factories from United States control, which had proven to be
1456-581: A previously diverse group of efforts. Several engineers from the RRDE were sent to the RAE at Farnborough Airport to aid the design of the tracking and guidance systems. Among the group was George Clarke, who had worked on the LOPGAP missile guidance system but was more interested in advanced radar development. In 1949 Clarke invented a novel sort of identification friend or foe (IFF) system that did not have to be triggered by
1560-458: A pulse sent from the ground. Instead, each airborne IFF would broadcast signals at random times. This avoided a problem seen in densely trafficked areas where the interrogation pulse from the ground IFF transceiver would generate so many transponder replies that they would overlap in time and interfere with each other. In Clarke's system the transponders naturally sent out replies spread out in time, making it much less likely they would overlap. In
1664-452: A purely real number in a passband of a lossless structure, varies with frequency. According to Floquet's theorem (see Floquet theory ), the RF electric field E(z,t) can be described at an angular frequency ω, by a sum of an infinity of "spatial or space harmonics" E n where the wave number or propagation constant k n of each harmonic is expressed as z being the direction of propagation, p
1768-473: A short time to perform its work, longer than the ideal scanning rate during the angle measurement. This could be solved with separate correlators at every measured angle, but the cost would be prohibitive. A new system was designed that used a small number of correlators and a computer as a memory system that allowed the detection of potential correlations to take place over the period of the scan. The correlators would make their measurement, store their results in
1872-472: A single IFF broadcast could be picked out of the many possible returns. By delaying the signals until they lined up in time, the difference in time that it took the signal to reach each of the antennas was extracted. The difference between any two antennas results in a continuum of possible locations along a hyperbola . By making similar measurements between all the stations, A-B, B-C and C-A, three such hyperbolas are constructed, which theoretically intersect at
1976-496: A single dot but a "constellation" of closely spaced dots. The operator could control the gain to make the weaker spots disappear, and then estimate the location of the aircraft in the remaining set. They would then use a normal voice telephone link to an operator at the L1 station, who would manually enter the location into the main displays. To aid the conversion from X-Y to a map location, the display added additional vertical lines to divide
2080-418: A single frequency defined by the physical dimensions of their resonators, and while the klystron amplified an external signal, it only did so efficiently within a small range of frequencies. Previously, jamming a radar was a complex and time-consuming operation. Operators had to listen for potential frequencies being used, set up one of a bank of amplifiers on that frequency, and then begin broadcasting. When
2184-410: A single point, but more typically form a small triangle due to inherent inaccuracies. The idea was not picked up for development. Later that year, Clarke proposed a new missile tracking and guidance system based on the same basic technique. Due to short flight times, a missile tracking system would want to detect the target as rapidly as possible, but as radars of the era were mechanically rotated, there
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#17330856184002288-434: A system able to deal with mass raids, so this solution was not appropriate. Correlators avoid this problem because they are extremely sensitive to the details of the signal pulses, to the point where pulses received from two different aircraft will not produce an output signal. Only when the correlator is fed the signals from the same jammer will a result be returned, thereby removing the ambiguity. Using correlation systems as
2392-404: A traditional IFF, the time between sending the interrogation pulse and its reception allowed the range to the transponder to be determined. In Clarke's system, the receiver did not know when the signal was sent, and could no longer use this method. Instead, the signal would be received by three antennas, and using a device known as a "correlator", better known today as a matched filter , pulses from
2496-575: A unique receiver design and responded to this need by introducing the Marconi Martello series of passive electronically scanned array (PESA) radars. For a variety of reasons, these were far less susceptible to jamming than radars that had to scan mechanically, and for most uses, these rendered the carcinotron much less effective. Martello's entered service with the RAF as the AMES Type 90 and Type 91 as part of
2600-518: Is a voltage tunable oscillator, whose voltage tuning rate is directly related to the propagation characteristics of the circuit. The oscillation starts at a frequency where the wave propagating on the circuit is synchronous with the slow space charge wave of the beam. Inherently the BWO is more sensitive than other oscillators to external fluctuations. Nevertheless, its ability to be phase- or frequency-locked has been demonstrated, leading to successful operation as
2704-517: Is a voltage-controlled non-resonant extrapolation of magnetron interaction. Both types are tunable over a wide range of frequencies by varying the accelerating voltage . They can be swept through the band fast enough to be appearing to radiate over all the band at once, which makes them suitable for effective radar jamming , quickly tuning into the radar frequency. Carcinotrons allowed airborne radar jammers to be highly effective. However, frequency-agile radars can hop frequencies fast enough to force
2808-421: Is dependent on a steady stream of electrons from an electron gun that travel down the center of the tube (see adjacent concept diagram ). Surrounding the electron beam is some sort of radio frequency source signal; in the case of the traditional klystron this is a resonant cavity fed with an external signal, whereas in more modern devices there are a series of these cavities or a helical metal wire fed with
2912-401: Is more negative than the cathode, in order to avoid collecting those electrons having gained energy while interacting with the slow-wave space harmonic. The O-type carcinotron , or O-type backward wave oscillator , uses an electron beam longitudinally focused by a magnetic field, and a slow-wave circuit interacting with the beam. A collector collects the beam at the end of the tube. The BWO
3016-451: Is not the case in the BWO, where the electrons pass the signal at right angles and their speed of propagation is independent of that of the input signal. The complex serpentine waveguide places strict limits on the bandwidth of the input signal, such that a standing wave is formed within the guide. But the velocity of the electrons is limited only by the allowable voltages applied to the electron gun, which can be easily and rapidly changed. Thus
3120-412: Is physically built into the resonator design, while the helix designs have a much wider bandwidth , perhaps 100% on either side of the design peak. The BWO is built in a fashion similar to the helical TWT. However, instead of the RF signal propagating in the same (or similar) direction as the electron beam, the original signal travels at right angles to the beam. This is normally accomplished by drilling
3224-430: Is received by the radar station. However, at long range the amount of energy from the original radar broadcast that reaches the aircraft is only a few watts at most, so the carcinotron can overpower them. The system was so powerful that it was found that a carcinotron operating on an aircraft would begin to be effective even before it rose above the radar horizon . As it swept through the frequencies it would broadcast on
RX12874 - Misplaced Pages Continue
3328-587: The AMES Type 85 . As these still had long range, only nine were needed to cover most of the UK. Over time these plans were repeatedly scaled back, eventually producing a system known as Linesman with three stations covering only the southern portions of England, protecting Bomber Command 's bases and the BMEWS radar. In 1947, the Royal Aircraft Establishment (RAE) was handed the task of developing guided missiles , taking over from
3432-595: The Ballistic Missile Early Warning System (BMEWS) radars by flying aircraft far offshore and using a carcinotron against the relatively narrow band of the BMEWS. They might mask a bomber attack on the V-force bases the same way by jamming the ROTOR radars. Such jamming would require the launch of the V-force while the nature of the threat was determined, and repeated spoofing of this sort could quickly wear out
3536-635: The British Rail Class 303 electric multiple units . In the 1950s, the company built a large power transformer works at Wythenshawe , Manchester. The factory opened in 1957, and was closed by GEC in 1971, after which it was sold to the American compressor manufacturer Ingersoll Rand . In 1961, the Russian cosmonaut Yuri Gagarin was invited to the company's factory at Trafford Park as part of his tour of Manchester. The rivalry between Metrovick and BTH
3640-454: The Metrovick F.2 and eventually flew in 1943 on a Gloster Meteor . Considered to be too complex to bother with, Metrovick then re-engineered the design once again to produce roughly double the power, while at the same time starting work on a much larger design, the Metrovick F.9 Sapphire . Although the F.9 proved to be a winner, the Ministry of Supply nevertheless forced the company to sell
3744-450: The ROTOR system, a comprehensive radar and control network covering the entire British Isles . The Catherine tests suggested that the system would be rendered impotent before it was even fully installed. The Royal Aircraft Establishment (RAE) immediately began developing their own carcinotrons for the V Bomber force under the name Indigo Bracket , while solutions to the jamming problem for
3848-621: The Western Australian Government Railways X class 2-Do-2 locomotive and in 1958 the type 2 Co-Bo, later re-classified under the TOPS system as the British Rail Class 28 . This diesel-electric locomotive was unusual on two counts; its Co-Bo wheel arrangement and its Crossley 2-Stroke diesel engine (evolved from a World War II marine engine). Intended as part the British Railways Modernisation Plan ,
3952-591: The electrification of the Woodhead Line in the early 1950s. Larger but broadly similar locomotives were also supplied to the New South Wales Government Railways as its 46 class . The company also designed the British Rail Class 82 , 25 kV AC locomotives built by Beyer, Peacock & Company in Manchester using Metrovick electrical equipment. The company also supplied electrical equipment for
4056-401: The phase velocity of one space harmonic of the wave is equal to the electron velocity. Both E z and E y components of the RF field are involved in the interaction (E y parallel to the static E field). Electrons which are in a decelerating E z electric field of the slow-wave, lose the potential energy they have in the static electric field E and reach the circuit. The sole electrode
4160-673: The shares of the Metropolitan Carriage, Wagon and Finance Company for almost £13 million. On 8 September 1919, Vickers changed the name of the British Westinghouse Electrical and Manufacturing Company to Metropolitan Vickers Electrical Company . The immediate post-war era was marked by low investment and continued labour unrest. Fortunes changed in 1926 with the formation of the Central Electricity Board which standardized electrical supply and led to
4264-402: The terahertz range. Belonging to the traveling-wave tube family, it is an oscillator with a wide electronic tuning range. An electron gun generates an electron beam that interacts with a slow-wave structure. It sustains the oscillations by propagating a traveling wave backwards against the beam. The generated electromagnetic wave power has its group velocity directed oppositely to
RX12874 - Misplaced Pages Continue
4368-465: The BWO takes a single input frequency and produces a wide range of output frequencies. The device was originally given the name "carcinotron", after the Greek name for the crayfish , which swim backwards. By simply changing the supply voltage, the device could produce any required frequency across a band that was much larger than any existing microwave amplifier could match - the cavity magnetron worked at
4472-521: The Chief of the Air Staff had concluded that close defence was useless, and began plans to remove anti-aircraft artillery from the defence. By December, planners believed the only practical role for air defence was to protect the V-force while it was launching. In keeping with this role, over the next few years the number of radar stations and fighters continued to be reduced as the protected area contracted around
4576-516: The French company CSF (now part of Thales Group ) introduced the carcinotron , a microwave -producing vacuum tube that could be tuned across a wide range of frequencies by changing a single input voltage. By continually sweeping through the frequencies of known radars , it would overpower the radar's own reflections, and blind them. Its extremely wide bandwidth meant that a single carcinotron could be used to send jamming signals against any radar it
4680-465: The Linesman system was extremely vulnerable. Worse, the carcinotron might be used against the microwave links between the stations, rendering the system useless. Even before it reached its Phase 1 availability, it was decided to abandon further improvements to the system and use those funds to design and purchase its replacement as soon as possible. Marconi had already been developing new radar systems using
4784-508: The Midlands. The 1957 Defence White Paper shifted priorities from manned bombers to missiles. The only way to defend against a missile attack was deterrence, so it was absolutely vital that the V-force survive. This meant that any attack, whether by aircraft or missiles, would require the V-force to launch immediately; the interceptor defence could not guarantee their survival even in the case of an all-bomber attack, and could do nothing at all in
4888-414: The RAF's radars were studied. The first consideration was that the carcinotron provided a relatively weak signal, on the order of 5 kW. When used in barrage mode, this was diluted to perhaps 5 to 10 W per MHz of bandwidth. Due to the radar equation , at long range this was still much stronger than the reflection of the multi-megawatt signal from the radar itself. As the jamming aircraft approached
4992-461: The Soviets could bomb the shore-side radars or even L1 with conventional weapons without fear of sparking a nuclear war. They would then have unfettered access to the UK's airspace. Since the Linesman system was designed primarily for early warning and anti-jamming during a short all-out nuclear war, it did not have the capability needed to deal with follow-up attacks. This shift in perceived threat implied
5096-443: The Type 85 was used primarily to measure the time of arrival of the signal, while the HSA rapidly scanned horizontally to extract a bearing. Information from HSAs and the Type 85s was combined in a correlator that used triangulation and time-of-flight information to determine the location of the jammer-carrying aircraft. Once the location was determined, it was manually input into the interception controller's displays as if it were
5200-554: The aircraft and their crews. A system for detecting such an attack and countering it was considered valuable. This role would not require the massive Blue Riband and led to the "Blue Yeoman" concept, combining the electronics of the Blue Riband with a smaller 45 by 21.5 foot (13.7 by 6.6 m) antenna originally developed as an upgrade for the Orange Yeoman radar. Associated Electrical Industries took up production of this system as
5304-575: The angle with an accuracy of about one degree. In order for the correlation to work, the signal from the two widely separated antennas had to be combined in the correlator. This was accomplished using a microwave relay between the stations. An experimental version was constructed between Great Baddow and the Royal Radar Establishment 's South Site in Great Malvern , about 100 miles (160 km) apart. A second system with prototype receivers
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#17330856184005408-420: The antenna had a wide acceptance area and its own scanning system, it did not necessarily have to rotate. In some modes, it could be set to one of four fixed angles arranged to cover either side of the baseline between the HSA and its associated Type 85. There were two settings on either side, "near look" and "far look". Alternately, the HSA could rotate in synchronicity with the Type 85 antenna, normally performing
5512-425: The case of missiles. By the end of 1957, the idea of any defence of the deterrent force had been abandoned; a bomber attack simply implied missiles were following. Now the bombers would launch to staging areas after receiving any credible threat. The need for the long-distance coverage of Blue Riband disappeared. One new role did emerge. Since the attack would likely come from missiles, the Soviets might attempt to jam
5616-569: The computer, and then be available for a measurement at another angle. Development went smoothly, and production started in 1962 even while development was ongoing. The first High Speed Aerial was built at Marconi's factory in Bushy Hill and connected to the prototype Blue Yeoman at the RRE in Great Malvern . The system was demonstrated to a NATO delegation in May 1964. The first production site at RAF Neatishead
5720-450: The concept suggested there were too many unknown factors to begin serious development, and Clarke was moved to a group working on radar countermeasures. In 1951, Clarke proposed a yet another system based on the same principles, this time as a way to track aircraft carrying jammers. The RAE considered the concept and suggested there were three possible ways it could be used; the first was the three-station concept of Clarke's missile proposal,
5824-419: The correlator value measured through one of the feed horns, and then it moved slightly to the right to repeat this for the next feed horn value. The result was an X-Y display with the X coordinate being the angle and the Y coordinate the range. Since the signal would likely be visible in several of the feed horns, as their reception patterns overlapped slightly in the horizontal axis, the target did not appear as
5928-504: The development of the PDS went fairly smoothly, the same was not true of the rest of the Linesman system. The Type 85 radars were repeatedly delayed and did not begin operation until 1968. The central control station in the London area was not fully functional until November 1973. By that time any plans to expand Linesman had been abandoned. The central site, known as L1, was not hardened. When Linesman
6032-776: The direction of motion of the electrons. The output power is coupled out near the electron gun. It has two main subtypes, the M-type ( M-BWO ), the most powerful, and the O-type ( O-BWO ). The output power of the O-type is typically in the range of 1 mW at 1000 GHz to 50 mW at 200 GHz . Carcinotrons are used as powerful and stable microwave sources. Due to the good quality wavefront they produce (see below), they find use as illuminators in terahertz imaging. The backward wave oscillators were demonstrated in 1951, M-type by Bernard Epsztein and O-type by Rudolf Kompfner . The M-type BWO
6136-417: The display into "sectors" which could then be looked up on a map. Due to the "stacked" vertical beams of the Type 85, height finding was still possible by examining which beams were receiving the jamming signal and which were clear of it. Carcinotron A backward wave oscillator ( BWO ), also called carcinotron or backward wave tube , is a vacuum tube that is used to generate microwaves up to
6240-429: The energy would be extracted. The effect of the signal on the passing beam causes the same velocity modulation effect, but because of the direction of the RF signal and specifics of the waveguide, this modulation travels backward along the beam, instead of forward. This propagation, the slow-wave , reaches the next hole in the folded waveguide just as the same phase of the RF signal does. This causes amplification just like
6344-523: The firm went on to complete 43 examples. With the design of the much improved four-engined derivative, the Avro Lancaster , MV switched production to that famous type, supplied with Rolls-Royce Merlin engines from the Ford Trafford Park shadow factory . Three hangars were erected on the southside of Manchester's Ringway Airport for assembly and testing of its Lancasters, before a policy switch
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#17330856184006448-411: The hope that they would not be known to the jammer in wartime. The carcinotron could still sweep through the entire band, but then it would be broadcasting on the same frequency as the radar only at random times, reducing its effectiveness. The other solution was to add passive receivers that triangulated on the carcinotron broadcasts, allowing the ground stations to produce accurate tracking information on
6552-446: The jammer to spread out its signal across a wide band, the radar randomly changed frequencies with every pulse, across a 500 MHz bandwidth. Through this period there had been an ongoing debate about the usefulness of air defences. The introduction of the hydrogen bomb meant a single aircraft could destroy any target, and the higher speeds and altitudes of bomber aircraft meant the bombs could be dropped from further away. By 1954,
6656-549: The jammer to use barrage jamming , diluting its output power over a wide band and significantly impairing its efficiency. Carcinotrons are used in research, civilian and military applications. For example, the Czechoslovak Kopac passive sensor and Ramona passive sensor air defense detection systems employed carcinotrons in their receiver systems. All travelling-wave tubes operate in the same general fashion, and differ primarily in details of their construction. The concept
6760-508: The jamming. However, interceptors of the era relied on ground direction to get into range, using ground-based radars. This represented an enormous threat to air defense operations. For ground radars, the threat was eventually solved in two ways. The first was that radars were upgraded to operate on many different frequencies and switch among them randomly from pulse to pulse, a concept now known as frequency agility . Some of these frequencies were never used in peacetime, and highly secret, with
6864-480: The jet division to Armstrong Siddeley in 1947 to reduce the number of companies in the business. In addition to building aircraft, other wartime work included the manufacture of both Dowty and Messier undercarriages, automatic pilot units, searchlights and radar equipment. They also produced electric vans and lorries . The post-war era led to massive demand for electrical systems, leading to additional rivalries between Metrovick and BTH as each attempted to one-up
6968-438: The location of the jammer and allowing them to be attacked. The needed slow-wave structures must support a radio frequency (RF) electric field with a longitudinal component; the structures are periodic in the direction of the beam and behave like microwave filters with passbands and stopbands. Due to the periodicity of the geometry, the fields are identical from cell to cell except for a constant phase shift Φ. This phase shift,
7072-555: The merger was marked by poor communication and intense rivalry, and the two companies generally worked at cross purposes. The next year the combined company was purchased by the Associated Electrical Industries (AEI) holding group, who also owned Edison Swan (Ediswan); and Ferguson, Pailin & Co , manufacturers of electrical switchgear in Openshaw, Manchester. The rivalry between Metrovick and BTH continued, and AEI
7176-408: The name ' Blue Riband '. It was assumed that a jammer could produce as much as 10 W per MHz across the entire S-band . Through the use of twelve 4.5 MW klystron transmitters broadcast through an enormous 75 by 50 foot (23 by 15 m) antenna system, the Blue Riband produced 11.4 W per MHz of reflected signal at 200 miles (320 km), thereby overpowering the assumed threat. To force
7280-454: The new threat of BMEWS-jamming was identified, the concept saw renewed interest. A design study for a system as part of the new radar deployment known as Plan Ahead, which later became Linesman, began in late 1958, followed by a development contract in August 1959. The basic concept required the correlator to be fed the same signal from the two antennas. This presented a problem; the correlator took
7384-493: The only measurement system would work, as Clarke originally proposed, but this would require two or three of correlators, which were very expensive. Thus, the concept using one angle measurement and one correlation was selected as the best compromise. Norman Bailey of the Telecommunications Research Establishment wrote a paper on the topic, which demonstrated the concept was feasible. In 1954, Marconi
7488-413: The order of 100 miles (160 km), the entire radar display would be completely filled with noise, rendering it useless. The concept was so powerful as a jammer that there were serious concerns that ground-based radars were obsolete. Airborne radars had the advantage that they could approach the aircraft carrying the jammer, and, eventually, the huge output from their transmitter would "burn through"
7592-417: The original signal; the density of the electrons in the beam matches the relative amplitude of the RF signal in the induction system. The electron current is a function of the details of the gun, and is generally orders of magnitude more powerful than the input RF signal. The result is a signal in the electron beam that is an amplified version of the original RF signal. As the electrons are moving, they induce
7696-496: The oscillator of only 1000–3000 K. Carcinotrón Metropolitan-Vickers Metropolitan-Vickers , Metrovick , or Metrovicks , was a British heavy electrical engineering company of the early-to-mid 20th century formerly known as British Westinghouse . Highly diversified, it was particularly well known for its industrial electrical equipment such as generators , steam turbines , switchgear , transformers , electronics and railway traction equipment. Metrovick holds
7800-426: The other in delivering ever-larger turbogenerator contracts. Metrovick also expanded its appliance division during this time, becoming a well known supplier of refrigerators and stoves. The design and manufacture of sophisticated scientific instruments, such as electron microscopes , and mass spectrometers , became an important area of scientific research for the company. In 1947, a Metrovick G.1 Gatric gas turbine
7904-400: The pitch of the circuit and n an integer. Two examples of slow-wave circuit characteristics are shown, in the ω-k or Brillouin diagram: A periodic structure can support both forward and backward space harmonics, which are not modes of the field, and cannot exist independently, even if a beam can be coupled to only one of them. As the magnitude of the space harmonics decreases rapidly when
8008-411: The radar display completely unreadable, filled with noise that hid any real targets. Useful jamming was accomplished even when the aircraft was under the radar horizon , in which case other aircraft had to be 20 miles (32 km) to the sides before they were visible outside the jamming signal. The system was so effective that it appeared to render long-range radar useless. The Type 80 was a key part of
8112-415: The radar station realized what was happening, they would change their frequencies and the process would begin again. In contrast, the carcinotron could sweep through all the possible frequencies so rapidly that it appeared to be a constant signal on all of the frequencies at once. Typical designs could generate hundreds or low thousands of watts, so at any one frequency, there might be a few watts of power that
8216-455: The radar's operating frequency at what were effectively random times, filling the display with random dots any time the antenna was pointed near it, perhaps 3 degrees on either side of the target. There were so many dots that the display simply filled with white noise in that area. As it approached the station, the signal would also begin to appear in the antenna's sidelobes , creating further areas that were blanked out by noise. At close range, on
8320-404: The ratio ω q /ω, where ω q is the angular plasma frequency; this ratio is of the order of a few times 10 . Measurements on submillimeter-wave BWO's (de Graauw et al., 1978) have shown that a signal-to-noise ratio of 120 dB per MHz could be expected in this wavelength range. In heterodyne detection using a BWO as a local oscillator, this figure corresponds to a noise temperature added by
8424-504: The receivers both receive the signal and measure its angle relative to their station. When these angles are plotted on a map, they intersect at a single location. If there are two jammer aircraft in the area, both stations will produce two angle measurements, one for each aircraft. When these are plotted on the shared map there will be four intersections; two of these hold aircraft, the other two are "ghosts". A third aircraft increases this to nine points and six ghosts, and so on. The RAF desired
8528-416: The same signal to the correlator, and the correlator would output a "match". When a match was seen, the HSA would then use its organ-pipe scanner to rapidly scan horizontally. The narrow beam of the Type 85 painted any single target for only about 1 ⁄ 50 of a second, and the HSA scanned the entire 70 degree space in front of it during that period. This is the origin of the name "high speed". During
8632-409: The same signal. As the electrons travel down the tube, they interact with the RF signal. The electrons are attracted to areas with maximum positive bias and repelled from negative areas. This causes the electrons to bunch up as they are repelled or attracted along the length of the tube, a process known as velocity modulation . This process makes the electron beam take on the same general structure as
8736-420: The scan, the jammer signal would still be visible to the Type 85, and would also appear in two or three of the feed horns on the HSA. These signals were fed into a bank of correlators. The correlation takes some time, so multiple correlators were needed in order to perform the comparisons in parallel for several of the feed horns at the same time. This was the purpose of storing the outputs in a computer; instead of
8840-409: The second used angular measurements from two widely spaced antennas for simple triangulation , the third used two antennas to find one hyperbola using Clarke's method, and an angular measurement from one of the two stations to intersect with it. While the two-angle solution might appear to be the simplest, it suffers from a problem when there is more than one jammer in an area. Against a single jammer,
8944-446: The station, there was some point where the radar began to overpower the jammer, the "self-screening" or "burn-through" point. A very powerful transmitter would increase the range where this occurred. Further improvement could be gained by tightly focusing the beam to put as much power into the reflected signal as possible. The Royal Radar Establishment (RRE) began development of such a system with Metropolitan-Vickers (Metrovick) under
9048-430: The traditional TWT. In a traditional TWT, the speed of propagation of the signal in the induction system has to be similar to that of the electrons in the beam. This is required so that the phase of the signal lines up with the bunched electrons as they pass the inductors. This places limits on the selection of wavelengths the device can amplify, based on the physical construction of the wires or resonant chambers. This
9152-538: The twenty-strong fleet saw service between Scotland and England before being deemed unsuccessful and withdrawn in the late 1960s. Metrovick also produced the CIE 001 Class (originally 'A' Class) from 1955, the first production mainline diesels in Ireland . Metropolitan Vickers also produced electrical equipment for the British Rail Class 76 (EM1), and British Rail Class 77 (EM2), 1.5 kV DC locomotives, built at Gorton Works for
9256-422: The value of n is large, the interaction can be significant only with the fundamental or the first space harmonic. The M-type carcinotron , or M-type backward wave oscillator , uses crossed static electric field E and magnetic field B, similar to the magnetron , for focussing an electron sheet beam drifting perpendicularly to E and B, along a slow-wave circuit, with a velocity E/B. Strong interaction occurs when
9360-459: Was a limit to their scanning rate. Clarke proposed using a single large "floodlight" transmitter and three receivers placed at the corners of a 15 miles (24 km) baseline triangle. The signal reflecting off of any object in the area would be converted into a location in the same way as the IFF system. All of the targets within the floodlit space could be located simultaneously and continually. A review of
9464-504: Was built in 1956 between RAF Bard Hill in Norfolk and RAF Bempton in Yorkshire . Initial tests were carried out with a jammer placed on a tower between the two stations, and this was used to further develop the correlator system. They eventually moved to aircraft tests. In one test, four aircraft, all carrying jammers, were correctly plotted. When Blue Riband was cancelled in early 1958, and
9568-400: Was deliberate, as it meant the two antennas on a baseline did not have to be pointing at the same target at the same time, something that would only be possible if the rough location was already known. Instead, the antennas simply had to be pointing in the same general point on the compass rose , and if a target was anywhere in front of either, their signals would line up in the correlator. As
9672-524: Was designed in the late 1950s, it was assumed that any war would quickly turn nuclear, and if H-bombs were going off there was no point in trying to prevent L1's destruction. However, as the USSR began to reach strategic parity with NATO in the late 1960s, this thinking changed. Now the idea of nuclear exchanges early in the war was no longer credible. It appeared that a lengthy conventional war would precede any nuclear one, or never become nuclear. In this setting,
9776-465: Was eventually ended in an unconvincing fashion when the AEI management eventually decided to rid themselves of both brands and be known as AEI universally, a change they made on 1 January 1960. This move was almost universally resented within both companies. Worse, the new brand name was utterly unknown to its customers, leading to a noticeable fall-off in sales and AEI's stock price. When AEI attempted to remove
9880-548: Was fitted to the Motor Gun Boat MGB 2009 , making it the world's first gas turbine powered naval vessel. A subsequent marine gas turbine engine was the G.2 of 4,500 shp fitted to the Royal Navy Bold-class fast patrol boats Bold Pioneer and Bold Pathfinder , which were built in 1953. The Bluebird K7 jet-propelled 3-point hydroplane in which Donald Campbell broke the 200 mph water speed barrier
9984-564: Was given a contract with the RAE to produce an experimental system under the code-name "Winkle". Most of the development work was carried out at the Marconi Research Centre in Great Baddow . They designed a system that used an antenna with a relatively wide acceptance angle, around 70 degrees horizontally, that was used while measuring the correlation. When a correlation was detected, an electronic scanning system would rapidly measure
10088-501: Was likely to meet, and the rapid tuning meant it could do so against multiple radars at the same time, or sweep through all potential frequencies to produce barrage jamming . The carcinotron was revealed publicly in November 1953. The Admiralty Signals and Radar Establishment purchased one and fit it to a Handley Page Hastings named Catherine , testing it against the latest AMES Type 80 radar late that year. As they feared, it rendered
10192-458: Was made to assembling them in a hangar at Avro's Woodford airfield. By the end of the war, MV had built 1,080 Lancasters. These were followed by 79 Avro Lincoln derivatives before remaining orders were cancelled and MV's aircraft production ceased in December 1945. In 1940 the turboprop effort was re-engineered as a pure jet engine after the successful run of Whittle's designs. The new design became
10296-619: Was never able to exert effective control over the two competing subsidiary companies. Problems worsened in 1929 with the start of the Great Depression , but Metrovick's overseas sales were able to pick up some of the slack, notably a major railway electrification project in Brazil . By 1933 world trade was growing again, but growth was nearly upset when six Metrovick engineers were arrested and found guilty of espionage and " wrecking " in Moscow after
10400-633: Was paid for by British government economic aid. In 1935 the company built a 105 MW steam turbogenerator , the largest in Europe at that time, for the Battersea Power Station . In 1936 Metrovick started work with the Air Ministry on automatic pilot systems, eventually branching out to gunlaying systems and building radars the next year. In 1938 they reached an agreement with the Ministry to build
10504-694: Was planned to start testing in October 1965, and the two following stations at RAF Staxton Wold and RAF Boulmer were completed ahead of schedule in early 1966. The first baseline using these three stations began testing in March 1966. After considerable testing and some minor corrections, the Staxton Wold site passed its acceptance trials in May/June 1968, and was handed to the RAF in October. Boulmer and Dundonald followed in November, and Neatishead in December. Although
10608-519: Was powered with a Metropolitan-Vickers Beryl jet engine producing 3,500 lbf (16 kN) of thrust. The K7 was unveiled in late 1954. Campbell succeeded on Ullswater on 23 July 1955, where he set a record of 202.15 mph (325.33 km/h), beating the previous record by some 24 mph (39 km/h) held by Stanley Sayres. Another major area of expansion was in the diesel locomotive market, where they combined their own generators and traction motors with third-party diesel engines to develop in 1950
10712-411: Was used to manufacture traction motors. By 1923, it had its own engineering department, and was making complete locomotives and electric delivery vehicles . In 1928 Metrovick merged with the rival British Thomson-Houston (BTH), a company of similar size and product lineup. Combined, they would be one of the few companies able to compete with Marconi or English Electric on an equal footing. In fact
10816-492: Was very different from its traditional heavy engineering activities, a new factory was built on the western side of Mosley Road and this was completed in stages through 1940. There were significant problems producing this aircraft, not least being the unreliability of the Rolls-Royce Vulture engine and that the first 13 Manchesters were destroyed in a Luftwaffe bombing raid on Trafford Park on 23 December. Despite this
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