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Topic: Beam tetrode

	loadmatch4-pp-beamtetrodes
		But tetrodes were twice as efficient as triodes, and a loop of NFB was cheap, the tetrode voltage gain was high, so they were easy to drive, so the beam tetrode was here to stay.
		In beam tetrode mode the screen is kept at fixed voltage to prevent the the anode voltage signal change from affecting the electron flow which occurs in triodes where the grid voltage changes AND the anode voltage changes BOTH have a net mutual effect on the electron current flow, due to electrostatic field effect action.
		If 6550 beam tetrodes are set up with a fixed screen voltage with CFB or not, then regardless of gain the Miller input capacitance is low and the output tubes are very easily driven at high frequencies, so little drive current is required in the driver amp.
	www.turneraudio.com.au /loadmatch4-pp-beamtetrodes.html (4653 words)

	Vacuum tube - Encyclopedia.WorldSearch (Site not responding. Last check: 2007-10-20)
		The beam power tube is usually a tetrode with the addition of "beam forming electrodes", which take the place of the suppressor grid.
		The positioning of the elements in a beam power tube uses a design called "critical-distance geometry", which minimizes the "tetrode kink", plate-grid capacitance, screen-grid current, and secondary emission effects from the anode, thus increasing power-conversion efficiency.
		The chief reliability problem of a tube is that the filament or cathode is slowly "poisoned" by atoms from other elements in the tube, which damage its ability to emit electrons.
	encyclopedia.worldsearch.com /thermionic_valve.htm (3111 words)

	Eimac Care and Feeding of Power Grid Tubes
		The additional grid serves as a shield, or screen, between the input circuit and the output circuits of the tetrode, and is called a "screen grid." In addition to serving as a shield, the screen is the accelerating element attracting the electrons from the cathode.
		Tetrodes permit the design of amplifier stages which can operate with driving power less than one per cent of the output power in most cases, and with negligible driving power in many audio applications.
		Tetrodes operate efficiently and with good life at audio and radio frequencies, including the VHF region (30 to 300 MHz) and in some cases into the UHF region (300 to 3000 MHz).
	www.cpii.com /eimac/sec2-2.htm (1379 words)

	Beam Tetrode
		The beam tetrode was developed as manufacturers were looking for a way to make audio output valves that would not infringe the Mullard (Philips) patent for the pentode.
		A beam tetrode employs principles not found in other types of valves in that the electron stream from the cathode is focused towards the anode.
		Beam valves were originally developed for use as audio-frequency output valves, but the principle was also applied to many types of radio-frequency tetrodes both for receiving and transmitting.
	www.r-type.org /static/grid14.htm (518 words)

	Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 13
		In the beam power tube, the basic four-element structure of the tetrode was maintained, but the grid and screen wires were carefully arranged along with a pair of auxiliary plates to create an interesting effect: focused beams or "sheets" of electrons traveling from cathode to plate.
		The oscillating electric and magnetic fields associated with the beam "echoed" inside the cavity, in a manner similar to the sounds of traveling automobiles echoing in a roadside canyon, allowing radio-frequency energy to be transferred from the beam to a waveguide or coaxial cable connected to the resonator with a coupling loop.
		This "velocity modulation" of the beam translated into the same sort of amplitude variation at the output resonator, where energy was extracted from the beam.
	www.ibiblio.org /obp/electricCircuits/Semi/SEMI_13.html (7356 words)

	loadmatching1sebeamtetrodes
		This beam forming action prevents secondary emissions from the anode and gives the wanted predictable beam tetrode characteristic curves which are very much like those of a pentode.
		The beam tetrode was invented to overcome the necessity of using power pentode tubes which were first patented in Europe.
		The advantages of the beam tetrode and power pentode allow for about twice the audio or RF output power compared to triodes which have a similar anode dissipation.
	www.turneraudio.com.au /loadmatch2-se-beamtetrodes.html (3516 words)

	Screen grid - Wikipedia, the free encyclopedia
		Indeed, as the secondary emission increases, the actual anode current can decrease, giving the tetrode valve a distinctive negative resistance characteristic, sometimes called "tetrode kink".
		This is more often than not unwanted, but can be exploited as in the dynatron oscillator.
		The secondary emission can be overcome by adding a suppressor grid or even beam plates to make repectively, a pentode or a beam tetrode.
	en.wikipedia.org /wiki/Screen_grid (329 words)

	Electron Beam Power Supply - Tetrode Tube - Theory of Operation
		The positive output is connected to the plate of a high-power tetrode tube.
		A power tetrode is used as the control element in a conventional series tube regulator configuration and is connected between the power supply positive output and ground.
		The tetrode also provides a means of interrupting the short-circuit, which results from high-voltage arcs to ground.
	www.thermionics.com /egun/ebeam_ps.htm (805 words)

	How Vacuum Tubes Work
		Large ceramic tetrodes are often called "radial beam tetrodes" or simply "beam tetrodes", because their electron emission forms a disc-shaped beam.
		This is a special kind of beam tetrode, with a pair of "beam plates" to constrain the electron beam to a narrow ribbon on either side of the cathode.
		Beam tetrodes still made today include the SV6L6GC and SV6550C; the former is most popular in guitar amplifiers, while the latter is the most common power tube in modern high-end audio amplifiers for the home.
	www.vacuumtubes.net /How_Vacuum_Tubes_Work.htm (6380 words)

	Power and Rectifier Tube Notes (Site not responding. Last check: 2007-10-20)
		Beam Tetrodes such as 6L6-GC, 5881 and 6550/KT88 are known for high efficiency at relatively low voltages, and in particular high peak current carrying capacity.
		The beam tetrode also can have a tendency to oscillate, especially big ones (like 6550's) or if run in multiple pairs.
		Beam tetrodes make very efficient triodes by wiring the screen to the plate (anode), usually via a small 100 ohm resistor.
	www.triodeel.com /ptnotes.htm (1152 words)

	Tubes Direct - The Tube Superstore - PM Guitar Tubes - Golden Dragon - Ei Elites
		This is a rugged version of the 6L6 beam tetrode originally used in industrial and military equipment.
		The 6V6GT small beam power tetrode tube with it’s indirectly heated cathode, designed for low frequency power amplification, is widely used in both audio and guitar applications.
		The Golden Dragon 807 is a beam powered tetrode, often found in older radio equipment and early hi-fi amps.
	www.tubesdirect.com /gd.asp (759 words)

	[No title] (Site not responding. Last check: 2007-10-20)
		The kinkless tetrode is a beam power tube [1].
		It differs from the ordinary tetrode in the same way that other beam tubes do; i.e., it provides a virtual suppressor [2].
		Beam tubes differ from other beam tubes mainly in the manner in which the electron stream is formed; i.e., in the shape and position of the beam formers [3].
	uts.cc.utexas.edu /~mic/info/amps/qanda/What-is-Kinkless-Tetrode (426 words)

	[No title]
		As for the overall effectiveness of the STC circuit, it appears (beam) tetrode and pentode power tubes give a very good result, while triode power tubes are somewhat poor.
		In case of a triode final stage, the bias voltage is higher than that for the tetrode or pentode topology, so some manipulation of the distribution of the supply voltage or the "bulk" voltage is required.
		For most tetrode or pentode STC V1 amplifiers, the screen grid power supply for the 1st stage amplifier is supplied from the cathode voltage of the final stage.
	www2u.biglobe.ne.jp /%7Ehu_amp/amput3e.htm (8095 words)

	The Tetrode - Electron Tubes
		As the name suggests, the tetrode tube contained four elements: cathode (with the implicit filament, or "heater"), grid, plate, and a new element called the screen.
		Similar in construction to the grid, the screen was a wire mesh or coil positioned between the grid and plate, connected to a source of positive DC potential (with respect to the cathode, as usual) equal to a fraction of the plate voltage.
		Two different strategies were developed to address this problem of the tetrode tube: beam power tubes and pentodes.
	www.opamp-electronics.com /tutorials/the_tetrode_3_13_04.htm (342 words)

	Retrovox c20store Beam Tetrodes
		Type 807 is an indirectly heated beam tetrode designed for use in the output stages of audio amplifiers and as an RF amplifier or frequency multiplier in transmitters.
		Pinout differs only in one respect to KT88 / 6550 types: Pin 6 is connected to the beam plates.
		TT21 beam tetrode designed for use in r.f.
	www.retrovox.com.au /c20store/beamtetrodes.html (504 words)

	Proceedings of the I
		All electron beams are now deflected clockwise and thus advanced in the direction of rotation, so that they strike all plate bars ahead of schedule.
		If the magnet field were reversed the deflection would be counterclockwise and would retard the arrival of the beams at the anodes.
		The rotating structure of electrostatic fields which produces the electron beams might well be compared to, the rotating magnetic field generated by the stator of a slow-running three-phase motor.
	www.w9gr.com /adler.html (3810 words)

	Wingfoot 813 Amplifier - Front and Side Views (Site not responding. Last check: 2007-10-20)
		Designed around the popular (in the 1950's) 813 beam power tetrode, the amplifier was unfinished and incomplete.
		There was also a power supply for the amplifier on a separate chassis, but the power supply had defective parts (particularly the filter capacitors) and was not operational.
		The 813 beam power tube, an RCA with a graphite plate, is also nicely shown.
	faculty.frostburg.edu /phys/latta/ee/wing813amp/amplifierpics1.html (1207 words)

	813 Beam Power Tube and Data Sheets (Site not responding. Last check: 2007-10-20)
		The 813 followed on the heels of the famous 6L6 beam power tube, which was the first power tube to use the electron beam principle.
		Forming the electrons into beams increased the space charge near the plate, which then repelled secondary electrons back to the plate, eliminating the need for a surpressor grid.
		Although a pair of 813s was perfect for legal limit operation on CW and AM, the tube was unable to supply the high peak inputs permitted in single sideband operation, and thus the popularity of the tube dropped as SSB became the preferred mode over AM.
	faculty.frostburg.edu /phys/latta/ee/wing813amp/813.html (401 words)

	IEEE Spectrum Select (Site not responding. Last check: 2007-10-20)
		These European tubes were true pentodes, different in electrical behavior from the beam tetrodes used in Fender amps.
		A modern OTL is the Transcendent Sound amplifier, which uses eight EL509 power tetrodes to produce 80 W into an 8-(omega) speaker load and is one of the few modern tube audio devices to be covered by a U.S. patent.
		In the guitar and pro-audio markets, new versions of classic power tetrodes and pentodes include, from the JJ/Teslovak Co., Cadca, Slovakia, the KT88S and E34LS, which are modified and uprated in power dissipation rating from their KT88 and EL34 prototypes.
	www.spectrum.ieee.org /select/0898/tube.html (6538 words)

	The Tube CAD Journal, Electrostatic Headphones Amps -Part 2-
		On the basis of listening tests (definitely not on the basis of measurements) the audio school has been divided into two camps--triodes versus tetrodes.
		When the triode-without-feedback was judged superior to the tetrode-without-feedback, the tetrode school added feedback and reaffirmed the merits of this tube type.
		This was again superseded by the triode-with-feedback, but the beam tetrode still has its followers, presently in the category of a defensive minority among the audio elite.
	www.tubecad.com /Classic_Articles/page2.html (575 words)

	Tetrode - Wikipedia
		Die Tetrode ist eine Vierpolröhre mit zwei Gittern.
		Eine Tetrode besteht aus einer Triode, wobei zwischen das Steuergitter und die Anode noch ein weiteres Gitter eingefügt wird, das Schirmgitter, welches sowohl als zweites Steuergitter, wie auch als eine virtuelle Anode betrachtet werden kann.
		Es vermindert die Rückwirkung der Anode auf das Steuergitter, den sog.
	de.wikipedia.org /wiki/Tetrode (200 words)

	Tubes
		Tetrode and Pentode connected amplifiers always supply the Screen-Grids either from the Plate Supply (B+) or a separate Screen-Grid supply, hence Screen-Grid Current is not usually a major consideration to amplifier designers - simply because Screen-Grid current needs are easily met by the power supply.
		The Screen-Grid voltage for Tetrodes should be obtained from a voltage divider or a potentiometer, rather than through a series resistor from a high-voltage source because of the characteristic Screen-Grid current variations of Tetrodes.
		In the case of tetrode and pentode operation, do not use excessive values of unbypassed (non-decoupled) Screen series resistance, because DC supply to the screen grid is likely to fluctuate substantially with screen current - thereby introducing non-linearity, as well as separating the screen from direct connection to AC ground.
	www.webace.com.au /~electron/tubes/screens.htm (13859 words)

	4CX350A/3821, Radial Beam Power Tetrode (Site not responding. Last check: 2007-10-20)
		The 4CX350A/8321 is a "Radial Beam Power Tetrode", has a 350 watts plate dissipation (max) and is intended for Class AB Audio or RF amplifier service.
		It is externally identical to the 250B model but contains very rugged internal construction features.
		Amplification factor and cathode area have been increased over the basic 250B model to give a higher transconductance and figure of merit.
	www.sentex.ca /~mec1995/4sale/4cx350a.html (63 words)

	FAQ
		807--beam power tetrode, often used in older radio equipment and some early hi-fi.
		7591--small beam power tetrode, common in old hi-fi and some guitar amps.
		8068--a glass beam power tetrode used in high-voltage power supplies, and sometimes in "homebrew" hi-fi amplifiers.
	www.vacuumtube.com /FAQ.htm (3726 words)

	Rec.antiques.radio+phono Radio Technical Questions(FAQ: 7/9)
		While there is no mistaking a 6A7, a T-9 beam power pentode with no markings may be a a 6W6, a 25L6, a 35L6, a 60L6, or a 6V6.
		Horizontal amplifiers on magnetic deflection sets ran with voltage and current levels appropriate for a transmitter, and several postwar sets continued to use the 807 beam tetrode as a horizontal amplifier tube, rather than one of the purpose-built tubes.
		If the ion trap is misadjusted, the electron beam won't be aimed at the phosphor screen properly, so the raster will be dim or nonexistent, or have "neck shadows" at the edges.
	www.faqs.org /faqs/antiques/radio+phono/faq/part7 (11633 words)

	Tube Information (Site not responding. Last check: 2007-10-20)
		L - output tetrode, beam tetrode, or pentode
		Digits indicate the base (first digit) and a code to distiguish valves that would otherwise have identical numbers (e.g.
		42, 52 etc - tetrode with screen grid (1st grid is control grid)
	www.octave-electronics.com /cus_links/tubeinfo.shtml (503 words)

	Virtual Valve Museum
		General categories: diodes, triodes, tetrodes/beam tetrodes, pentodes, hexodes, heptodes, octodes, nonodes, multiples, others (e.g.
		Museum info/Displays/Donations/Sponsorship - please help the museum - see the About section.
		18/06/07 Added CV4034 double triode, VR18 and CV2730 tetrodes, ARPT1 triode/pentode, and CV504 tuning indicator.
	www.tubecollector.org (216 words)

	Tube 6L6
		The 6L6GC is a glass envelope beam-power tetrode intended for high-power audio amplifier service.
		May be operated in inverted position--base fits into socket clamps in Fender guitar amplifiers.
		Grid no. 1 to cathode, heater, grid no. 2, and beam forming plates
	www.tube.be /6l6.html (164 words)

	6-15 kW Electron Beam Power Supply - Tetrode Tube
		It is necessary to install an additional, independent filament controller and transformer for each extra gun.
		Includes 2 ampere current regulated power supplies for positioning the beam anywhere in the crucible.
		For more information about Thermionics Vacuum Products please call our sales engineers at 800-962-2310, fax us at 360-385-6617, or e-mail us at sales@thermionics.com.
	www.thermionics.com /egun/ps_specs.htm (288 words)

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