DOCSLIB.ORG

Jan. 17, 1961 R. C. A. ELAND 2,968,742 HIGH EFFICIENCY TRIODE WACUUM TUBE Filed July 25, 1958 3

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Jan. 17, 1961 R. C. A. ELAND 2,968,742 HIGH EFFICIENCY TRIODE WACUUM TUBE Filed July 25, 1958 3 Jan. 17, 1961 R. C. A. ELAND 2,968,742 HIGH EFFICIENCY TRIODE WACUUM TUBE Filed July 25, 1958 3. Sheets-Sheet 1 2. NIT "it NTT I It TT A. 7? 173 -2 \ze INVENTOR. M26a767 a.4.222W2 BY / ?%ael Jan. 17, 1961 R. C. A. ELAND 2,968,742 HIGH EFFICIENCY TRIODE WACUUM TUBE Filed July 25, 1958 3. Sheets-Sheet 2 INVENTOR. Mezaa27.2 AZ1/WA BY 22-62-4-2 2T241772-ezar 2,968,742 United States Patent Office Patented Jan. 17, 1961 2 tube in conjunction with a high efficiency output circuit 2,968,742 thereacross more efficient, as is fully described herein after. This advantageous gain is acomplished in the HIGH EFFICIENCY TRODEVACUUM TUBE present invention without increasing the noise factor, or Robert C. A. Eland, Arcadia, Calif., assignor to Standard 5 degrading other advantageous characteristics of the triode Coil Products Co., Inc., Melrose Park, Ill., a corpora vaccum tube. tion of Illinois As is well known in the art, a triode vacuum tube is essentially a diode to which a third or control electrode Filed July 25, 1958, Ser. No. 750,956 is added between the cathode and the plate electrodes for 5 Claims. (C. 313-293) 10 the purpose of controlling the flow of electrons to the plate. The control grid electrode is in the form of a screen or lattice, serving as an imperfect electrostatic shield. The control grid is usually operated at a negative This invention relates generally to triode vacuum potential with respect to the cathode, thereby controlling tubes, and more particularly relates to novel triode con 5 the number of electrons that pass between the grid wires struction that increases its overall gain performance and on their way to the plate electrode. efficiency in high frequency amplifier circuits. Under such negative bias arrangement substantially Practical and commercial triode vacuum tubes have no grid current flows, and accordingly the amplification substantially lower dynamic plate resistances than those by the triode is with relatively low noise figure as com of tetrode and pentode vacuum tubes. The addition of 20 pared to any tube with a screen grid electrode. The the screen grid electrode in tetrode and pentode vacuum amount of electrons reaching the plate electrode under tubes substantially increases their dynamic plate resist usual charge-limited conditions is determined practically ance so that a typical RF output circuit connected to its by the electrostatic field in the cathode-to-grid space. output operates at optimum. - Once the electrons pass the grid electrode, they travel The susbtantially large dynamic plate resistance of 25 rapidly to the plate electrode, wherein space-charge screen grid tubes does not reduce the efficiency or over effects in the grid-to-plate space may be neglected. all Q of high frequency output circuits. The amplification factor of a triode is designated by The dynamic plate resistance of tetrodes and pentodes the constant mu. Mu is a measure of the relative effec is of the order of several hundred thousand ohms. On tiveness of the grid and plate voltages in introducing the other hand, the corresponding dynamic plate resistance 30 of triodes is of the order of thousands of ohms in typical electrotatic fields at the surface of the cathode, and is constructions, and at best, of the order of tens of thou accordingly a measure of the screening effect of the con sands of ohms. Thus a highly efficient or high Q output trol grid. The constant mu is determined by the geome circuit of a triode RF stage cannot attain optimum per try of the tube construction, and is generally independent formance due to the loading down effect thereon by the 35 of the voltages applied to the grid and the plate elec internal impedance of the triode tube connected there trodes. aCOSS The amplification factor depends primarily upon the In a given triode tube electrode configuration, the dy grid structure and construction, and is increased by what namic plate resistance may be increased by reducing the ever causes the grid electrode to more completely shield capacity between the plate and control grid electrodes. 40 the cathode from te plate. Closer spacing of the grid This correspondingly increases the amplification factor wires, or larger diameter grid wires, accordingly result in or mu of the triode tube. In tetrodes and pentodes such a higher mu factor. Also, an increase in the distance be interelectrode capacity reduction is accomplished by the tween the grid and plate electrodes produces a higher added screen grid electrode. In cascode circuitry of the amplification factor mu. For RF amplifiers, commercial type shown in the Nelson Patent 2,775,659, the second ly available triode vacuum tubes of prior constructions triode stage is connected as a grounded grid amplifier 45 have mu factors ranging from about five to about one to accomplish equivalent results. hundred. In the case of pentode and tetrode tubes, current In accordance with the present invention, I incorporate drawn by the screen grid increases the noise figure of the one or more shielding elements in the vicinity between tube, and accordingly Such tubes are inferior to triodes the control grid structure and the plate electrode. The where noise performance is important, as in television 50 shielding elements are made independent electrically of reception. In the case of television tuners in VHF range, the grid and plate electrodes, and arranged in a novel namely from 54 to 216 megacycles, the high dynamic manner to substantially lower the electrostatic control plate resistance of tetrodes and pentodes cannot all be effect that the plate exerts upon the cathode surface, with utilized in the RF stage due to the band width require out changing the effect that the grid has at the same point. ments. In the case of a single triode RF amplifier stage, 55 In other words, a larger change in plate voltage is there the available dynamic plate resistance in such tubes con upon required to exert a given electrostatic change at the structed heretofore is approximately 72 to /3 lower than cathode surface that the same triode requires without is requisite for optimum gain performance. such shield elements. The result is a higher amplifica In accordance with the present invention, the capacity tion factor, or mu, for the tube as will be hereinafter between the plate and control grid electrodes of a triode 60 set forth in detail. The dynamic plate resistance of the vacuum tube is reduced in a novel manner by a factor triode is correspondingly increased by these shield of two to three, to one. The dynamic plate resistance of elements. the resultant triode of the invention is thereby made suf In accordance with the present invention, the total ficiently high to perform in an amplifier stage to yield plate electrode structure is made larger than requisite for an overall gain comparable to that of tetrode, pentode 65 conducting the electron current of the triode. The active and cascode amplifier stages, i.e. where the transconduct portion of the plate structure is placed opposite the cath ance of the tubes is of the same order. ode and control grid electrodes, as heretofore, but with The interellectrode capacitance reduction between the the inactive plate portions extending therefrom. The plate and control grid electrodes correspondingly in shield elements are interposed between the grid electrode creases the dynamic plate resistance of the triode vacuum 70 and the inactive plate portions to electrostatically shield tube and renders the overall amplification action of the themreferred to accomplishto above. the increased mu and plate resistance 2,968,742 3 4. Such large plate structure is utilized to provide Figure 8 is an enlarged perspective view showing the ruggedness thereto, and prevent microphonics in the triode internal components of the triode of Figure 7. operation. Further, the larger or heavier plate structure Figures 9 through 14 are diagrammatic illustrations hereof, additionally affords adequate heat radiation to of several other forms which the triode of the present maintain a practical dissipation for the tube in operation. invention may assume in practice. There is no increase in the tube volume. The principles Figure 15 is a schematic electrical diagram of an RF of the present invention are applicable to triode structures amplifier circuit incorporating a triode vacuum tube of of various types, configurations, and sizes, as will be here the present invention. inafter set forth. Figure 16 is a diagrammatic representation of the tuned 0. output circuit of the RF amplifier stage of Figure 15. The added shield elements within the triode of the In Figure 1 is illustrated one embodiment of a triode present invention increases the electrostatic isolation be vacuum tube incorporating the principles of my invention tween the control grid and plate electrodes. This results herein. The triode vacuum tube 20 comprises an evacu in a substantially lower amount of oscillator voltage ap ated glass envelope 21. Mounted within envelope 21 is pearing on the grid electrode in a superheterodyne tuner a generally cylindrical plate structure 22, a central tu incorporating such triode in the input RF amplifier stage. bular cathode 23, and a helical grid structure 24 between Accordingly, when used in an RF or television tuner, ra plate structure 22 and cathode 23. The triode electrodes diation of oscillator signal from the antenna is reduced namely plate 22, cathode 23 and control grid 24, are significantly, particularly at the higher frequencies. anchored within the vacuum tube 20 in any suitable well The triode vacuum tube of the present invention is 20 known manner. accordingly eminently suited for use in high frequency The plate structure 22 comprises two active plate elec amplifiers, and in tuner circuitry such as for FM and trode surface portions 25, 26 exposed to control grid 24 television receivers in the first RF stage thereof.
Load more

Recommended publications
  • El156 Audio Power
    EL156 AUDIO POWER Gerhard Haas Thanks to its robustness, the legendary EL156 audio power pentode has found its way into many professional amplifier units. Its attraction derives not just from its appealing shape, but also from its impressive audio characteristics. We therefore bring you this classical circuit, updated using high- quality modern components. 28 elektor electronics - 3/2005 AMPLIFIER Return of a legend The EL156 was manufactured in the enough to give adequate sensitivity, electrolytic capacitor: this voltage is legendary Telefunken valve factory in even before allowing any margin for further filtered on the amplifier board. Ulm, near the river Danube in Ger- negative feedback. The ECC81 many. The EL156 made amplifiers with (12AT7), however, which has an open- It is not possible to build an ultra-lin- an output power of up to 130 W possi- loop gain of 60 and which can be oper- ear amplifier using the EL156 with a ble, using just two valves in the output ated with anode currents of up to high anode voltage. The same goes for stage and one driver valve. Genuine 10 mA, can be used to build a suitably the EL34. The output transformer is EL156s are no longer available new at low-impedance circuit. therefore connected in such a way that realistic prices, and hardly any are Two EL156s can be used to produce an the impedance of the grid connection available second-hand. The original output power of 130 W with only 6 % to the output valve is much lower than devices used a metal valve base which distortion.
    [Show full text]
  • Valve Biasing
    VALVE AMP BIASING Biased information How have valve amps survived over 30 years of change? Derek Rocco explains why they are still a vital ingredient in music making, and talks you through the mysteries of biasing N THE LAST DECADE WE HAVE a signal to the grid it causes a water as an electrical current, you alter the negative grid voltage by seen huge advances in current to flow from the cathode to will never be confused again. When replacing the resistor I technology which have the plate. The grid is also known as your tap is turned off you get no to gain the current draw required. profoundly changed the way we the control grid, as by varying the water flowing through. With your Cathode bias amplifiers have work. Despite the rise in voltage on the grid you can control amp if you have too much negative become very sought after. They solid-state and digital modelling how much current is passed from voltage on the grid you will stop have a sweet organic sound that technology, virtually every high- the cathode to the plate. This is the electrical current from flowing. has a rich harmonic sustain and profile guitarist and even recording known as the grid bias of your amp This is known as they produce a powerful studios still rely on good ol’ – the correct bias level is vital to the ’over-biased’ soundstage. Examples of these fashioned valves. operation and tone of the amplifier. and the amp are most of the original 1950’s By varying the negative grid will produce Fender tweed amps such as the What is a valve? bias the technician can correctly an unbearable Deluxe and, of course, the Hopefully, a brief explanation will set up your amp for maximum distortion at all legendary Vox AC30.
    [Show full text]
  • P1-Extreme Amplifier by David Sorlien, Revised and Updated by Stephen Keller
    Introduction to Tube Amplifier Theory: 10.02.15 Featuring the AX84 P1-eXtreme Amplifier by David Sorlien, revised and updated by Stephen Keller The P1-eX amplifier is a simple three-stage vacuum tube electric guitar amplifier. As outlined in Fig. 1, it consists of two preamp stages driving a power amp stage. Depending on the choice of output tube, this amp is can deliver between 7 and 15 watts into a 4-, 8-, or 16-ohm load. Fig. 1: P1-eX block diagram Placed between the two preamp stages is a preamp volume control. In a similar manner, the bass, middle, and treble tone controls and a master volume control are placed between the preamp and the final power amp stage. The guitar amplifier performs two primary functions: One, it amplifies the small voltages and currents produced by the guitar pickup into a signal powerful enough to drive a speaker. Two, it shapes the frequency response, tonality, and distortion characteristics of the raw guitar signal into a form pleasing to the musician. To better grasp how a guitar amplifier accomplishes these functions, let©s take a walk through the inner workings of the AX84 P1-eXtreme amp (P1-eX). For reference, there is copy of revision 06.03.16 of the schematic provided in Appendix 1 at the end of this document. To fully understand how a guitar amp works, even a simple one like the P1-eX, you must know how to read schematic diagrams, and understand what things like resistors and capacitors are. You also need some knowledge of basic algebra and electronic theory.
    [Show full text]
  • The Development of the Vacuum Tube Creators
    The Knowledge Bank at The Ohio State University Ohio State Engineer Title: The Development of the Vacuum Tube Creators: Jeffrey, Richard B. Issue Date: May-1928 Publisher: Ohio State University, College of Engineering Citation: Ohio State Engineer, vol. 11, no. 7 (May, 1928), 9-10. URI: http://hdl.handle.net/1811/34260 Appears in Collections: Ohio State Engineer: Volume 11, no. 7 (May, 1928) THE OHIO STATE ENGINEER The Development of the Vacuum Tube By RICHARD B. JEFFREY, '31 The history of the vacuum tube began with the discovery of the Edison Effect. This, like a great many other important discoveries, was an acci- dent. Edison, while experimenting with his in- candescent lamps, had placed more than one fila- output ment in the same bulb, and he noticed that if one of the filaments was held positive with respect to the other a current would flow through the bulb. He also found that this positive element, or, as it is now called, plate, did not have to be hot to sustain this current flow. This phenomenon li—- H was known for some time as a curiosity, but noth- 1 +90 to \35 ing more. Then Fleming, an English experiment- +4-5 er, noticed that if an alternating current were The screen-qrid tube (tetrode). applied to this plate the current would flow only plicated system by making use of the rectifying when the plate was positive. In other words, the properties of a crystal, notably galena. When tube acted as a rectifier, allowing the current to signals were received in this way it was the signal flow in only one direction.
    [Show full text]
  • The Beginner's Handbook of Amateur Radio
    FM_Laster 9/25/01 12:46 PM Page i THE BEGINNER’S HANDBOOK OF AMATEUR RADIO This page intentionally left blank. FM_Laster 9/25/01 12:46 PM Page iii THE BEGINNER’S HANDBOOK OF AMATEUR RADIO Clay Laster, W5ZPV FOURTH EDITION McGraw-Hill New York San Francisco Washington, D.C. Auckland Bogotá Caracas Lisbon London Madrid Mexico City Milan Montreal New Delhi San Juan Singapore Sydney Tokyo Toronto McGraw-Hill abc Copyright © 2001 by The McGraw-Hill Companies. All rights reserved. Manufactured in the United States of America. Except as per- mitted under the United States Copyright Act of 1976, no part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written permission of the publisher. 0-07-139550-4 The material in this eBook also appears in the print version of this title: 0-07-136187-1. All trademarks are trademarks of their respective owners. Rather than put a trademark symbol after every occurrence of a trade- marked name, we use names in an editorial fashion only, and to the benefit of the trademark owner, with no intention of infringe- ment of the trademark. Where such designations appear in this book, they have been printed with initial caps. McGraw-Hill eBooks are available at special quantity discounts to use as premiums and sales promotions, or for use in corporate training programs. For more information, please contact George Hoare, Special Sales, at [email protected] or (212) 904-4069. TERMS OF USE This is a copyrighted work and The McGraw-Hill Companies, Inc.
    [Show full text]
  • Operation, Tetrode, Pentode in the Single-Ended, Class-A
    10-76 10. Guitar Amplifiers 10.5.1 Single-ended (class A)-operation, tetrode, pentode In the single-ended, class-A power-stage, one (single) power-tube operates in common- cathode configuration with the output transformer being part of the plate circuit (transformer- coupling). Without AC-drive (“quiescent state”), a stable balance appears – it is called the operating point (OPP). The characteristics shown in Fig. 10.5.2 yield an OPP at 250 V and 48 mA, if a voltage of -7.5 V between (control) grid (g1) and cathode is chosen. This can be done e.g. by using a cathode-resistor of 142 Ω. The cathode-current (the sum of the 48-mA- plate-current and the 5-mA-screen-grid-current) will then generate a positive cathode-voltage of + 7.5 V (relative to ground). With the control-grid at ground-potential (Ug1 = 0) a control- grid-to-cathode-voltage of -7.5 V results (i.e. the control grid is negative vs. the cathode). Fig. 10.5.2: Output characteristics of the EL84, power-stage circuit (single-ended class-A operation). AP = OPP As a drive signal appears (Ug1 ≠ 0), plate-voltage and –current change. As a first approach, it will be sufficient to consider the transformer in the plate-circuit as a large inductance connected in parallel with an ohmic resistor (Chapter 10.6). In this model we have only pure DC flowing through the inductance, and only pure AC flowing through the resistor. With a drive-signal present, the Ua/Ia-point will move along the load-line given in Fig.
    [Show full text]
  • 6\ M?L/ K7 Gmwy 4 I ' + /‘4 I- E 7 4-‘1 :"I'yl’‘‘‘‘ ‘N I ‘ 7'0 LP 2: J- = ' '
    Oct.’ 8, 1940. s. HUNT £2,217,277 ' ‘ DEGENERATIVE PLATE cmcun: DETECTOR Filed Sept. '28, 19:8 DEGENERAT/VE PLATE __———_C/RCU/T DETECTOR | /2 6\ M?l/ k7 gmwy 4 i ' + /‘4 i- E 7 4-‘1 :"I'Yl’‘‘‘‘ ‘n I ‘ 7'0 LP 2: J- = ' ' a . °~ I ?|__' I ~ 70 A. E AMPLIFIER INVENTOR. Ilse MOUR HUNT BY ATTORNEY. Patented Oct. 8, 1940 2,2l7,277 UNITED STATES F ICE 2,217,277 DEGENERAT'IVE PLATE CIRCUIT DETECTOR Seymour Hunt, Jackson Heights, Long llsland, N. Y., assignor to Radio Corporation of Amer ica, a corporation of Delaware Application September 28, 1938, Serial No. 232,075 6 Claims. (Cl. 256-4237) My present invention relates to detector cir art are fully acquainted with the construction of cuits, and more particularly to degenerative plate superheterodyne receivers, it is not believed nec circuit detectors capable of substantially ampli essary to explain the construction thereof at any fying the audio voltage output thereof. greater length. The output electrode for the 5 One of the main objects of this invention is to detector circuit includes electrode 4. Preferably, provide a detector of the in?nite impedance type this electrode is a wound grid. The latter is con which includes an electronic section having a nected through load resistor 52 to the plus B negative mutual conductance characteristic terminal of any desired direct current source, which functions to amplify the audio output of such as the usual direct current energizing source 10 the detector. of a radio receiver. The coupling condenser l3 Another important object is to provide in a transmits the audio voltage, in ampli?ed form, biased plate circuit detector of the degenerative to the following audio ampli?er for ?nal repro type a negative mutual conductance section duction.
    [Show full text]
  • Electrostatic Design and Characterization of a 200 Kev Photogun and Wien Spin Rotator
    Old Dominion University ODU Digital Commons Electrical & Computer Engineering Theses & Dissertations Electrical & Computer Engineering Spring 2021 Electrostatic Design and Characterization of a 200 keV Photogun and Wien Spin Rotator Gabriel G. Palacios Serrano Old Dominion University, [email protected] Follow this and additional works at: https://digitalcommons.odu.edu/ece_etds Part of the Computer Engineering Commons, Electrical and Computer Engineering Commons, and the Physics Commons Recommended Citation Palacios Serrano, Gabriel G.. "Electrostatic Design and Characterization of a 200 keV Photogun and Wien Spin Rotator" (2021). Doctor of Philosophy (PhD), Dissertation, Electrical & Computer Engineering, Old Dominion University, DOI: 10.25777/mf9f-r453 https://digitalcommons.odu.edu/ece_etds/224 This Dissertation is brought to you for free and open access by the Electrical & Computer Engineering at ODU Digital Commons. It has been accepted for inclusion in Electrical & Computer Engineering Theses & Dissertations by an authorized administrator of ODU Digital Commons. For more information, please contact [email protected]. ELECTROSTATIC DESIGN AND CHARACTERIZATION OF A 200 keV PHOTOGUN AND WIEN SPIN ROTATOR by Gabriel G. Palacios Serrano B.S. August 2014, Universidad Autónoma Metropolitana, Mexico M.S. May 2017, Old Dominion University A Dissertation Submitted to the Faculty of Old Dominion University in Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY ELECTRICAL AND COMPUTER ENGINEERING OLD DOMINION UNIVERSITY May 2021 Approved by: Helmut Baumgart (Director) Carlos Hernández (Member) Linda Vahala (Member) Mohammad Obeid (Member) Gon Namkoong (Member) ABSTRACT ELECTROSTATIC DESIGN AND CHARACTERIZATION OF A 200 keV PHOTOGUN AND WIEN SPIN ROTATOR Gabriel G. Palacios Serrano Old Dominion University, 2021 Director: Dr.
    [Show full text]
  • Cre|4|L-Feuhis ATTORNEYS Nov
    Nov. 28, 1961 M. V. SULLIVAN 3,011,018 HIGHLIGHT APERTURE CORRECTION SYSTEM Filed Sept. 26, 1956 3 Sheets-Sheet 1 NVENTOR MICHAEL V.SULL VAN cre|4|l-feuHIS ATTORNEYS Nov. 28, 1961 M. W. SULLIVAN 3,011,018 HIGHLIGHT APERTURE CORRECTION SYSTEM Filed Sept. 26, 1956 3 Sheets-Sheet 2 aa- ?-s? ? O ???? S I INVENTOR MICHAEL V. SULLIVAN -a?.--77. ? ????? ??? HIS AT TORNEYS Nov. 28, 1961 M. V. SULLIVAN 3,011,018 HIGHLIGHT APERTURE CORRECTION SYSTEM Filed Sept. 26, 1956 3 Sheets-Sheet 3 NVENTOR MiCHAEL V. SULLIVAN Y Cit...!!* His A ?????? la? 3,011,018 United States Patent Office Patented Nov. 28, 1961 3,011,018 FIG. 2 illustrates the waveform of the television pic HIGHLIGHT APERTURE CORRECTION SYSTEM ture signal at various points in the aperture equalization Michael V. Sullivan, Florham Park, N.J., assignor to system shown in FIG. 1; Columbia Broadcasting System, Inc., New York, N.Y., FIG. 3 is a circuit diagram of the input and white a corporation of New York clipper portions of the system shown in FIG. 1; Filed Sept. 26, 1956, Ser. No. 612,221 FIG. 4 is ? circuit diagram of the difference ampli 7 Claims. (Cl. 178-6) fier portion of the system shown in FIG. 1; and FIG. 5 is a circuit diagram of the summing amplifier This invention relates to television, and more particu and output portions of the system shown in FIG.1. larly to a new and improved aperture equalization O Referring first to the block diagram of FIG. 1 and method and means for correcting aperture distortion in the graphic representations of the signal waveform of the highlight regions of the television picture, without FIG.2, a television picture information signal as illus increasing the high frequency noise which is inherent in trated in FIG.
    [Show full text]
  • Tutorial: Adding a Control Grid to a High-Current Electron Gun
    Tutorial: adding a control grid to a high-current electron gun Stanley Humphries, Copyright 2012 Field Precision PO Box 13595, Albuquerque, NM 87192 U.S.A. Telephone: +1-505-220-3975 Fax: +1-617-752-9077 E mail: techinfo@fieldp.com Internet: http://www.fieldp.com 1 Recently, I was asked to consider whether a control grid consisting of parallel or crossed wires could be added to an existing space-charge-limited electron gun for beam modulation. I identified two main questions: • Because considerable effort had been invested in the gun design, would it possible to add the grid without significantly changing the macro- scopic beam optics? • What was the contribution to the angular divergence of the beam rel- ative to the focal requirements? With regard to first question, the best approach would be to locate the wire grid at the former position of the cathode surface and to move the cathode a short distance upstream. The grid would be attached to the focus electrode bounding the former cathode surface. Figure 1 is a schematic view of the cathode-grid region. The values of D and Vc should be chosen to generate an electron current density je equal to the space-charge limited design value in the main acceleration gap. In this way, the grid surface would act almost like the original cathode, preserving the gun optics. There are two options to fabricate a grid: 1) parallel wires with spacing W or 2) a crossed grid with square openings with side length W . For a rough estimate, I did not consider the effect of the wire width.
    [Show full text]
  • BY 7% É Arrórney Patent-Ed Nov
    Nov. 24, 1942. s. HUNT 2,302,867 COMÈINED MIXER AND INTERMEDIATE FREQUENCY STAGE l Filed Oct. 25, 1941 Q/ T - l INVENToR ’ SEYMOUR BY 7% é ArróRNEY Patent-ed Nov. 24, 1942 2,302,867 . UNITED STATES PATENT OFFICE tratas@r COMBINED MIXER AND INTÉRMEDIATE FREQUENCY STAGE Seymour Hunt, Flushing, N. Y., assîgnor to Radio Corporation of America, a corporation of Dela Ware Application october 25, 1941, serial No. 416,438 8 Claims. (>Cl. 250-20) This invention is concerned with an improve ` accelerate the electron stream and to shield elec ment in radio receivers of the superheterodyne trostatically the signal control grid G4 from volt type and more particularly with a combined first age fluctuations on the oscillator anode-grid G2 detector-oscillator or mixer and intermediate fre and the output anode P. quency stage that may be used with advantage in Cl According to my invention the functions of such receivers. the several electrodes and the connections there In the present state of the art it isknown to tol of the circuit elements are modified somewhat use in superheterodyne circuits a multi-electrode ~ as will now be pointed out more particularly. In type of tube designed to perform simultaneously the circuit of Fig. 1 the grid G1 serves as the the functions of a mixer tube and of an oscillator signal control grid as well as the oscillator grid. tube. According to my present invention the ` Connected between the signal grid G1 and cath same or equivalent multi-electrode tube is made ode 'is the circuit L1-C1 which is tuned to the to perform in addition the function of interme received signal oscillations.
    [Show full text]
  • Pentodes Connected As Triodes
    Pentodes connected as Triodes by Tom Schlangen Pentodes connected as Triodes About the author Tom Schlangen Born 1962 in Cologne / Germany Studied mechanical engineering at RWTH Aachen / Germany Employments as „safety engineering“ specialist and CIO / IT-head in middle-sized companies, now owning and running an IT- consultant business aimed at middle-sized companies Hobby: Electron valve technology in audio Private homepage: www.tubes.mynetcologne.de Private email address: [email protected] Tom Schlangen – ETF 06 2 Pentodes connected as Triodes Reasons for connecting and using pentodes as triodes Why using pentodes as triodes at all? many pentodes, especially small signal radio/TV ones, are still available from huge stock cheap as dirt, because nobody cares about them (especially “TV”-valves), some of them, connected as triodes, can rival even the best real triodes for linearity, some of them, connected as triodes, show interesting characteristics regarding µ, gm and anode resistance, that have no expression among readily available “real” triodes, because it is fun to try and find out. Tom Schlangen – ETF 06 3 Pentodes connected as Triodes How to make a triode out of a tetrode or pentode again? Or, what to do with the “superfluous” grids? All additional grids serve a certain purpose and function – they were added to a basic triode system to improve the system behaviour in certain ways, for example efficiency. We must “disable” the functions of those additional grids in a defined and controlled manner to regain triode characteristics. Just letting them “dangle in vacuum unconnected” will not work – they would charge up uncontrolled in the electron stream, leading to unpredictable behaviour.
    [Show full text]