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	Cavity magnetron - Wikipedia, the free encyclopedia
		A cavity magnetron is a high-powered vacuum tube that generates coherent microwaves.
		Simple two-pole magnetrons were developed in the 1920s by Albert Hull at General Electric, as an outgrowth of his work on the magnetic control of vacuum tubes in an attempt to work around the patents held by Lee DeForest on electrostatic control.
		The cavity magnetron was widely used during World War II in microwave radar equipment, and is often credited with giving Allied radar a considerable performance advantage over German and Japanese radars, thus directly influencing the outcome of the war.
	en.wikipedia.org /wiki/Magnetron (1494 words)

	[No title] (Site not responding. Last check: 2007-10-09)
		Provided therein is an apparatus that includes a microwave resonant cavity, a magnetron for generating microwaves and a means for continuously controlling the power of the magnetron, with the means comprising a temperature control system, specifically an optical fibre pyrometry system, and a solid state control circuit.
		The cavity resonator 22 is configured such that a mass of ceramic 66 is capable of continuously passing though the inside of the resonator as it is heated and dried; i.
		Since energy radiated by the adjustable microwave power source 11, or magnetron, is converted indirectly to reflected power of the ceramic mass within the cavity 11, a change in energy generated by the magnetron causes an instantaneous change in the reflected power generated by the mass of ceramic 66 within the cavity 22.
	www.wipo.int /cgi-pct/guest/getbykey5?KEY=01/05191.010118&ELEMENT_SET=DECL (2794 words)

	MAGNETRON (Site not responding. Last check: 2007-10-09)
		A magnetron is a high-powered vacuum tube that generates coherent microwaves.
		A magnetron consists of a hot filament kept at or pulsed to a high negative potential by a high voltage direct current power supply.
		Since then, many millions of cavity magnetrons have been manufactured; some for radar, but the vast majority for another application that was completely unanticipated at the time - the microwave oven.
	www.yotor.org /wiki/en/ma/Magnetron.htm (720 words)

	Microwave oven with adaptable power module - Patent 4956531
		A microwave oven as claimed in claim 4, wherein the air channel is formed by a cooling plate extending between the air inlet and the air outlet within the envelope and separating a part of the interior of the envelope from the rest of the interior of the envelope.
		A microwave oven as claimed in claim 1, wherein the air channel is formed by a cooling plate extending between the air inlet and the air outlet within the envelope and separating a part of the inner interior of the envelope from the rest of the interior of the envelope.
		The magnetron 12 is in this case mounted in such a way on the envelope 10 that its antenna 36 projects perpendicular to the broad-side of the envelope and extends through the said opening 35 into the groove shaped recess 33.
	www.freepatentsonline.com /4956531.html (2566 words)

	Miscellanea
		It is not generally realised that the cathode of a magnetron is very quickly stripped of its coating and after passing current for a total time of only a few hours a magnetron is quite useless.
		Magnetron cathodes are made to give as long a life as possible by special surface treatments but the life is still short only a few hours.
		Since the life of a magnetron is limited it is important to have a convenient way of testing magnetrons in use.
	www.radarpages.co.uk /mob/misc/misc7.htm (403 words)

	CPI / BMD Products Including Receiver Protectors, Switches, Pressure Windows, Magnetrons, Traveling Wave Tubes, Crossed ...
		The resonant frequency of a microwave cavity is thereby determined by the physical dimension of the resonator together with the reactive effect of any perturbations to the inductive or capacitive portion of the equivalent circuit.
		Operating the cavity in the TE011 mode, and slot coupling alternate anode resonators to the cavity, produces anode control of such intensity as to permit the construction of coaxial magnetrons with many times the number of resonators that can be employed in a conventional type magnetron.
		When estimating magnetron frequency change due to temperature coefficient, keep in mind that the temperature coefficient relates magnetron frequency to body temperature and there is not necessarily a 1:1 relation between body temperature and, for example, ambient air temperature.
	www.cpii.com /bmd/mag1.htm (3154 words)

	Magnetron Operation (Site not responding. Last check: 2007-10-09)
		The microwave radiation of microwave ovens and some radar applications is produced by a device called a magnetron.
		The magnetron is called a "crossed-field" device in the industry because both magnetic and electric fields are employed in its operation, and they are produced in perpendicular directions so that they cross.
		As these electrons sweep toward a point where there is excess negative charge, that charge tends to be pushed back around the cavity, imparting energy to the oscillation at the natural frequency of the cavity.
	hyperphysics.phy-astr.gsu.edu /hbase/waves/magnetron.html (234 words)

	[3.0] Microwave Radar & The MIT Rad Lab (Site not responding. Last check: 2007-10-09)
		The core of the cavity magnetron was a thick copper cylinder, with a large central tunnel bored through it.
		Similarly, the frequency output of the cavity magnetron was dependent on the size of the cavities.
		The cavity magnetron was so promising that Oliphant's group abandoned their work on the klystron to work with the new device.
	www.vectorsite.net /ttwiz3.html (6628 words)

	Talk:Cavity magnetron - Wikipedia, the free encyclopedia
		It was not my intent to write the killer historical article on the magnetron, and without the preceding authors I would have had no basis to start from and would probably not have attempted to write an article from scratch.
		Gleaned from the reference [1] was a mention of early "two pole" and more later "six pole" magnetrons, incapable of producing significant power.
		As the "cavity magnetron" is what is most commonly thought of when "magentron" is mentioned, I think that it stands best as it is. Leonard G. 02:47, 10 Mar 2005 (UTC)
	en.wikipedia.org /wiki/Talk:Magnetron (1185 words)

	Privateline.com Telephone History: Radar History by Buderi Page 2
		It was this overriding concern--not just in regards to the cavity magnetron but extended to all the devices in the fl box--that brought Bowen to the Euston platform that August morning.
		Besides the crucial cavity magnetron, nearly everything about radar could be found in the fl box; and several containers of working sets and components apparently had been sent through separate channels to supplement its contents.
		Today cavity magnetrons are used in microwave cookers as well as for detecting radio waves reflected from a flying aircraft.
	www.privateline.com /TelephoneHistory3/radarhistorybuderi.html (4533 words)

	session 6-3
		It was a single magnetron oven, weighing 86 lb, operating at 2450 Mc, and providing approximately 1200 W of power in the oven cavity.
		The E-30 airline microwave oven is a double magnetron unit weighing 110 lb, operating at 2450 Mc, and providing approximately 2400 W of power in the enlarged oven cavity.
		Advancement in the general state of the art of all types of microwave ovens and the old cliche that "necessity is the mother of invention" explain the drastic changes that took place in the evolution of the E-30 sensing devices.
	history.nasa.gov /SP-202/sess6.3.htm (1704 words)

	The Magnetron - an overly simplistic explanation (Site not responding. Last check: 2007-10-09)
		The earlier primitive magnetron consisted of an evacuated glass envelope containing a thin vertical cathode surrounded by four anode segments connected to external resonating circuits.
		When a high voltage was applied to the anodes, the large magnetic field from the coil of an electromagnet surrounding the envelope caused electrons emitted from the hot cathode to spin in circles across the surfaces of the anodes, exciting oscillations in the external resonating circuits.
		Almost as soon as it was created one of the prototype cavity magnetrons was taken to the USA together with a plea for help in developing an anti-U boat device.
	www.westwight.clara.co.uk /Mag.htm (1232 words)

	[No title] (Site not responding. Last check: 2007-10-09)
		The initiator is disposed in the antinodes of the resonator and the discharge chamber and is oriented with respect to the electric vector oscillations in the resonator.
		The initiator is disposed in the resonator cavity and in the discharge chamber.
		Usually when a cavity resonator is used to achieve a microwave breakdown level, a gas discharge which forms when intensity reaches a breakdown level, spreads over the whole resonator volume.
	www.wipo.int /cgi-pct/guest/getbykey5?KEY=00/60910.001012&ELEMENT_SET=DECL (3107 words)

	Sci.Electronics.Repair FAQ: Notes on the Troubleshooting and Repair of Microwave Ovens (Site not responding. Last check: 2007-10-09)
		Since the oven chamber cavity is a good reflector of microwaves, nearly all the energy generated by the oven is available to heat the food and heating speed is thus only dependent on the available power and how much food is being cooked.
		The magnetron is most often box shaped with cooling fins in its midsection, the filament/HV connections on the bottom section, and the antenna (hidden by the waveguide) on top.
		The gap between the cathode and anode, and the resonant cavities, are all in a vacuum.
	www.eio.com /repairfaq/REPAIR/F_micfaq2.html (4385 words)

	radar
		The cavity magnetron had a substantial increase in performance over other magnetrons of its time and it played a substantial role in the history of radar.
		Because Randall and Boot built a cavity magnetron, the claim that the British invented radar is made.
		Habann is generally given the credit of being the inventor of the magnetron from which the cavity magnetron evolved.
	www.radarworld.org /england.html (986 words)

	IEEEVM: The Cavity Magnetron
		The cavity magnetron was the first practical device for producing microwaves.
		The cavity magnetron was invented in England under wartime pressures.
		By May, other researchers were using the cavity magnetron in a radar set that could detect a submarine periscope six miles away.
	www.ieee-virtual-museum.org /collection/tech.php?id=2345892&lid=1 (727 words)

	E639/10 @ The National Valve Museum (Site not responding. Last check: 2007-10-09)
		The E639/10 magnetron is a development of the original magnetrons.
		A major secret of the second world war was the development of the cavity magnetron for radar.
		These early magnetrons were not particularly stable and they did not find widespread use, unlike the cavity magnetron.
	www.r-type.org /exhib/aab0126.htm (120 words)

	IFC - Acquisition Radars
		This was the multi-cavity magnetron The arrival of the
		For instance, after the cathode was heated by the filament current, and the magnetron was pulsed with the high voltage pulses, there were so many electrons that would gain energy then come crashing back to the cathode that the cathode would over heat unless the cathode heater current was reduce or eliminated.
		This describes a microwave oven magnetron, which does not have the pulse width and tunability requirements of a radar magnetron, but the principle is identical.
	ed-thelen.org /ifc_acq.html (9158 words)

	MICROWAVE OVENS (Site not responding. Last check: 2007-10-09)
		When it is active, the magnetron's cavity has electric charge sloshing back and forth along its tines.
		The charge moves at a frequency determined by the shape and size of the cavity and these are carefully controlled so that the cavity's natural resonance frequency is 2.45 GHz.
		A small wire connected inside the magnetron extracts some of the energy in the magnetron and converts it into microwaves outside the magnetron.
	landau1.phys.virginia.edu /classes/106N/1995/omp/032095.html (1736 words)

	H2S radar - TheBestLinks.com - January 30, Luftwaffe, World War II, 1943, ... (Site not responding. Last check: 2007-10-09)
		This develoment was possible thans to the development of the cavity magnetron.
		The H2S team also protested that it would take the Germans two years to develop a centimetric radar once the cavity magnetron fell into their hands, and that there was no reason to believe they weren't working on the technology already.
		The first concern would prove correct; the second would fortunately be proven wrong, though given the widespread parallel development of the cavity magnetron, in hindsight it wasn't an unreasonable assumption.
	www.thebestlinks.com /H2S_radar.html (1438 words)

	Search Results for magnetron - Encyclopædia Britannica
		Magnetrons are primarily used to generate power at microwave frequencies for radar systems, microwave ovens, plasmas, linear accelerators, and the creation of plasmas used for such applications as...
		The opening of higher frequencies (those of the microwave region) to radar, with its attendant advantages, came about in late 1939 when the cavity magnetron oscillator was invented by British...
		American physicist who independently discovered the powder method of X-ray analysis of crystals, which permits the study of crystalline materials in a finely divided microcrystalline, or powder,...
	www.britannica.com /search?query=magnetron&submit=Find&source=MWTAB (321 words)

	How a tube and a slide rule helped win WWII \| csmonitor.com
		Lab assistants were sent on a succession of errands to the local garage for higher and higher wattage bulbs to connect to the output, but each was burned to a crisp.
		The resonant cavity magnetron was generating so much power it was burning up everything they connected to it.
		Resembling a tin of tuna fish with protruding spines, the resonant cavity magnetron was small enough to fit in the palm of a man's hand.
	www.csmonitor.com /2004/0603/p14s02-stct.htm (1636 words)

	REL3D / NT98
		It was the first magnetron suitable for use as a radar transmitter.
		The serial number of this magnetron is Q24136 and it has the number 8827 written on the anode block.
		The output port is on the right but this magnetron was damaged and the output loop has been distorted.
	www.tubecollector.org /rel3d.htm (215 words)

	TESLA, Inc. (a non profit corporation) Proposal: PROJECT TESLA The Demonstration of Artifi
		The electromagnetic techniques to be used to transmit power in the Schumann Cavity are similar to microwave signal generation in a magnetron cavity and propagation in a waveguide.
		If the same amount of power is put into the cavity on each cycle of oscillation of the transmitter, there will be a net energy gain which will result in a net voltage, or amplitude increase.
		As long as energy is delivered to the cavity, the process will continue until the energy is removed by heating, lightning discharges, or as is proposed by this project, loading by tuned circuits at distant locations for power distribution.
	www.skepticfiles.org /mys4/prjtesla.htm (3402 words)

	Nat' Academies Press, In War and Peace: My Life in Science and Technology (2002)
		The cavity magnetron did that, a claim the Americans confirmed in tests a few weeks after the Washington meeting.
		But as remarkable as the cavity magnetron was, microwave radar also needed further development of its components—receiver, detector, and so forth—to be a workable device.
		A few weeks after the cavity magnetron came to the United States, a major laboratory to exploit it was up and running.
	www.nap.edu /openbook.php?record_id=10374&page=26 (601 words)

	AMT - Industrial Microwave Heating Technology
		Energy entering the cavity is then absorbed deep into the wool bale(s) causing an increase in temperature.
		The generator is a stand alone device containing the magnetron, power supply, circulator and all control functions associated with the system operation.
		The chain conveyor inside the cavity will oscillate the bale during the heating cycle to ensure heating is homogeneous throughout.
	www.amtmicrowave.com /wool.html (705 words)

	WebPosition Detail Report (Site not responding. Last check: 2007-10-09)
		Magnetrons for all types of microwave oven, Capacitors, Diodes, Transformers, Turntable motors, and other items are...
		Damaging of the magnetrons is mainly caused by lack of...
		Magnetron heads from 300 to 2000 watts (2 kW) are...
	www.footedgestage.com /stats/cobermuegge-2/Detail-MSN-2.htm (4359 words)

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