DOCSLIB.ORG

TI S4 Audio Frequency Test Apparatus.Pdf

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
TI S4 Audio Frequency Test Apparatus.Pdf TECHNICAL INSTRUCTION S.4 Audio-frequency Test Apparatus BRITISH BROADCASTING , CORPORATION ENGINEERING DlVlSlON - ', : . iv- TECHNICAL INSTRUCTION S.4 Third Issue 1966 instruction S.4 Page reissued May. 1966 CONTENTS Page Section I . Amplifier Detector AD14 . 1.1 Section 2 . Variable Attenuator AT119 . Section 3 . Wheatstone Bridge BG/I . Section 4 . Calibration IJnit CALI1 . Section 5. Harmonic Routine Tester FHP/3 . Section 6 . 0.B. Testing Unit 0BT/2 . Section . 7 . Fixed-frequency Oscillators OS/9. OS/ 10. OS/ IOA . Section 8 . Variable-frequency Oscillators TS/5 .. TS/7 . 1' . TS/8 . TS/9 . TS/ 10. TS/ 1OP . Section 9 . Portable Oscillators PTS/9 . PTS/IO . ... PTS/12 . PTS/13 . PTS/l5 .... PTS/l6 .... Appendix . The Zero Phase-shift Oscillator with Wien-bridge Control Section 10. Transmission Measuring Set TM/I . Section 1 I . Peak Programme Meter Amplifiers PPM/2 ..... PPM/6 . TPM/3 . Section 12 Valve Test Panels VT/4. VT/5 "d . Section 13. Microphone Cable Tester MCT/I . Section 14 . Aural Sensitivity Networks ASN/3. ASN/4 Section 15 . Portable Amplifier Detector PAD19 . Section 16. Portable Intermodulation Tester PIT11 Section 17. A.C. Test Meters ATM/I. ATM/IP . Section 18 . Routine Line Testers RLT/I. RLT/IP . Section 19. Standard Level Panel SLP/3 . Section 20 . A.C. Test Bay AC/55 . Section 21 . Fixed-frequency Oscillators: OS2 Series Standard Level Meter ME1611 . INSTRUCTION S.4 Page reissued May 1966 ... CIRCUIT DIAGRAMS AT END Fig. 1. Amplifier Detector AD14 Fig. 2. Wheatstone Bridge BG/1 Fig. 3. Harmonic Routine Tester FHP/3 Fig. 4. Oscillator OS/9 Fig. 5. Oscillator OS/10 Fig. 6. Oscillator OS/lOA Fig. 7.' Peak Programme Meter Amplifier PPM/2 Fig. 8. Peak Programme Meter Amplifier PPM/6 Fig. 9. Oscillator PTS/9 Fig. 10. Transmission Measuring Set TM/1 Fig. 1I. Test Programme Meter Amplifiers TPM/3 and TPM/3A Fig. 12. Tone Source TS/5 : Amplifier Fig. 12~.Tone Source TS/5: Oscillator and Detector Fig. 13. Tone Source TS/7 Fig. 14. Tone Source TS/8 Fig. 15. Valve Test Panel VT/4: Circuit Fig. 16. Valve Test Panel VT/4: Valve-holder Panel Fig. 16~.Valve Test Panel VT/4 : Adaptor Panel Fig. 17. Valve Test Panel VT/5 Fig. 18. Portable Tone Source PTS/I 3 Fig. 19. Tone Source TS/9 Fig. 20. Portable Tone Source PTS/ 10 Fig. 21. Portable Tone Source PTS/I2 Fig. 22. Portable Amplifier Detector PAD19 Fig. 23. Portable Amplifier Detector PAD/9: Modified for use with P.P.M. Fig. 24. Portable Intermodulation Tester PIT11 . Fig. 25. A.C. Test Meters ATM/l and ATM/lP Fig. 36. Routine Line Tester RLT/1 Fig. 27. Routine Line Tester RLT/lP Fig. 28. Tone Source TS/10 and TS/lOP Fig. 29. Standard Level Panel SLP/3 Fig. 30. AC.. Test Bay AC/55 Fig. 31. Intermodulation Test Oscillator IT011 Fig. 32. Amplifier Test Panel ATPI1 Fig. 33. Telephone Panel TP/12 Fig. 34. Relay and Repeating-coil Panel RRC/1 Fig. 35. Oscillator OS2/4 SECTION 1 AMPLIFIER DETECTOR AD;4 The Amplifier Detector AL)/I' is essentially a anode voltage, a stabiliser, coiisisting of a Metrosil \.alve voltmeter designed to read levels of -+ 10 db disk working in conjunction with R19, is includrtl to - 55 db. Its input impedance is 30 kilohms in the h.t, supply circuit of V.3. which is sufficiently high to permit its connection across most circuits without altering the voltagc Negative Feedback or operating conditions of the sending circuit. 'fhr high gain available from \'1 and 1'2 permits Fig. I. I. Face Panel AD:4 with Simpson Meter Circuit Description (Fig. I) tlw use of a consideraldc ;mount oi feedback. The input to the unit is taken via a11 input \Yitli \'I, serirs feedback of 1"l) is ilcwloprtl transformer, TI, to a 10-kilohm potentiomrtcr, ;moss I<" to compvnsate for high-frequency loss, Pa65P, having 14 studs, calibrated in steps of thc ferdhack is rcdr~cedby abor~t0-1 db at 10 kc-s 5 tlb, with an off position. This is followcd bj. and by about 0.2 dh at 15 kc,s. This recluctior~ two resistance-capacitance coupled stages which is effected by shunting CH and R20 across R2. use high-gain pentodrs. \'arinl)lc series feedback is usrd over V2, V3 and Tl~eoutpr~t stage to the rectificbr AIKI metctr ~xovides;i ready means of ndjusting thc working circuits consists of a triode, workcd at low anodc :rain iinr.l for lining up the meter. Tl~cfecdback \.oltage. This res~iltsin the \xlvc working near \-oltngc is rlevelopetl in thc cathoilt- circr~i.tnf \.I! tlit 01-crload point : to minimisc. instabilit!. of th~~across R1.5 and R8 : 118 is variahlc to provides :LII Instruction S.4 Section 1 adjust-gain control ; its ~~ljustmentvaries the performed carefully ant1 cannot be hurried, sincc output current of V3 which flows throiigh the the mcter movemcnt is rclativcly slow. rectifier-meter circuit. i'C.leas/tri)~,qLevels Gain Controls It should be clearly untlcrstood that the AD/I The calibrated gain controls used for taking was designed primarily for the measurement of tone rneasurcments consist of the two potentiometers level as distinct from programme volume, for 1'/65P and P/64P. The P/65P is variablc in steps of which latter purpose a test programme meter is 5 db over a range of - 50 to + 10 db ; thc P/6?P more suitable. To check a given level, set the is variablc in stel)s of 0.5 dl, over a rangc of calibrated controls to correspond with this level, O to -- ,5 db. wherever possible setting the 0-5 dl) control to zero. Adiust thc fine control until the meter reads as near tb mid-scale deflection as possible. The Meter Circuits level is then obtained by the algebraic sum of the The anodc of the third stage fecds into a 1 mA rcadings of the two controls and the scale reading Westinghousi: bridge-connccted metal rectifier of of the meter. the meter type via a 20-kilohm rcsistor R14 and For cxample, if it be required to measure a level ;I I-microfarad capacitor C6. Thc output of this which slioultl normally be + 10 db, set the coarse recliticr is taken to thc terminals of an appro- control to + 10 tlb and the fine control to zero db. priate tylr of indicating mcter. If the meter ,reads well off mid-scale, adjust the Two typcs of indicating meter can be used, the fine control accordingly. If the nearest adiustmcnt !'limpson type, with normal veriical scale requiring is at - 2 db, on the fine control, and the meter ;L fectl of 1 mA for full scidc tlcflcclio:~, or the reads j--0.4 tlb, then the actual level is + 10 - 2 Elliott edgewise typc as usctl on the Trar~smission + 0.4 =:: -1- 8.4 dl). Measuring Set TM/l. Thc Simpson type meter is coniicctcd direct to thc rectifier output, but thc Elliott typc rcquircs to be shunted by a 30-ohm Supplies rcsistor. The ultcrnativc connections are shnun The unit is designetl to work from a 250-volt or i11 Fig. I. a 300-volt battery or a rcctitied h.t, supply. The Uoth meters arc calibrated for zero at mitl- 1.t. supply may be taken from batteries or from scnlc deflection, the scde being cxtencld to cover the mains, except in cases of iiistruments having a %ll, swing cither side of zcro, the calibration serial numbers below 136. Thcse carlicr models bcbin:y in stcps of 0.2 db. 1-Icnct. it is possiblc to have an unscreenetl input transformcr and arc obtain readings thc accuracy of which can be subject to a certain amount of hum pick-up. nio:lsured to within + 0.2 tlb, provitlcd that the Present practice is for ncw installations to be ii~ctcrreadings be correctly inttqolatcd betwecn provided with a mains unit, Typc MUIIG. thr rcatlings of thc calibrated potcntionctcrs. Valve Data Operation Anode Screen \1'hencvcr possible, the amplifier tlctector should Current Current FiL Fil. I)c switched on for at least ten minutes be for^ use mA . nzA 1,'olfs Amps. in order to ensurc stability. Stage 1, Calibmtion AC /SP3,1 1.2 0.35 4 1 Sct tlic Adj!jr(stGain potentiometcr to its extreme Stage 2, anti-clocl<wisc or minimum-gain position. Conncct ACjSP31i 145 0.4 4 I thc input of the AD/? to the output of a tone Stagc 3, source having a calibrated output level (e.g. AC>HI, 1.6 - 4 1 CBLj1). Sct the AD14 calibrated potentiometcrs Jletrosil Current 6 mA. to zero or +. 10 db, according to the sending level, Total Fccrl, 11 mA. 2nd turn ul) the Adjust Gain potcntiomcter until H.T. Supply, 300 1. or 250 \'. 11lc incter rcatls zero. This operation must be T,.'17. Supply, 4 1' a.c, or 6 1. d.c. Instruction S.4 Section 1 General Data Ampllfier Detectors AD/4A, AD/4B, AD/4C, l'otentinmslsrs AD/4D No. of Loss per All these models use thc samc basic circuit as Tybr' Rssistancs Sl~rds Stud the AD/4, but are moun ted on 9-inch panels instead Coarse of the nornial 64-inch panel. Adjustment P165P 10 kIl I4 .idb. AD[?A is a converted AD/2. Fin, AD/4B is a converted ADIS, with Muirhead Adjust-ment P/64P 100 kt2 I I 0-5dh, potentiometers. Adjust Gain AD/4C is a converted AD13 with fainton potentio- Type, Reliance TW.
Load more

Recommended publications
  • The Absolute Measurement of Capacity
    THE ABSOLUTE MEASUREMENT OF CAPACITY. By Edwakd B. Rosa and Frederick "W. Grover. 1. The Method Employed. The usual method of determining the capacity of a condenser in electromagnetic measure is Maxwell's bridge method, using a tuning fork or a rotating commutator to charge and discharge the condenser, Fig. 1. which is placed in the fourth arm of a Wheatstone bridge. This is a null method, is adapted to measuring large and small capacities equally well, and requires an accurate knowledge only of a resistance and the rate of the fork or commutator. 153 154 BULLETIN OF THE BUREAU OF STANDARDS. [vol.1, no. 2. The formula for the capacity C of the condenser as given by J. J Thomson, is as follows: * i_L a (a+h+d){a+c+g) 0= (1) ncd \} +c{a+l+d))\} + d(a+c+g)) in which <z, c, and d are the resistances of three arms of a Wheatstone bridge, b and g are battery and galvanometer resistances, respectively, and n is the number of times the condenser is charged and discharged per second. When the vibrating arm P touches Q the condenser is charged, and when it touches P it is short circuited and discharged. When Pis not touching Q the arm BD of the bridge is interrupted and a current flows from D to C through the galvanometer; when P touches Q the condenser is charged by a current coming partly through c and partly through g from C to D. Thus the current through the galvanometer is alternately in opposite directions, and when these opposing currents balance each other there is no deflection of the gal- vanometer.
    [Show full text]
  • Equivalent Resistance
    Equivalent Resistance Consider a circuit connected to a current source and a voltmeter as shown in Figure 1. The input to this circuit is the current of the current source and the output is the voltage measured by the voltmeter. Figure 1 Measuring the equivalent resistance of Circuit R. When “Circuit R” consists entirely of resistors, the output of this circuit is proportional to the input. Let’s denote the constant of proportionality as Req. Then VRIoeq= i (1) This is the same equation that we would get by applying Ohm’s law in Figure 2. Figure 2 Interpreting the equivalent circuit. Apparently Circuit R in Figure 1 acts like the single resistor Req in Figure 2. (This observation explains our choice of Req as the name of the constant of proportionality in Equation 1.) The constant Req is called “the equivalent resistance of circuit R as seen looking into the terminals a- b”. This is frequently shortened to “the equivalent resistance of Circuit R” or “the resistance seen looking into a-b”. In some contexts, Req is called the input resistance, the output resistance or the Thevenin resistance (more on this later). Figure 3a illustrates a notation that is sometimes used to indicate Req. This notion indicates that Circuit R is equivalent to a single resistor as shown in Figure 3b. Figure 3 (a) A notion indicating the equivalent resistance and (b) the interpretation of that notation. Figure 1 shows how to calculate or measure the equivalent resistance. We apply a current input, Ii, measure the resulting voltage Vo, and calculate Vo Req = (1) Ii The equivalent resistance can also be measured using and ohmmeter as shown in Figure 4.
    [Show full text]
  • CCIF (Geneva, 1954)
    This electronic version (PDF) was scanned by the International Telecommunication Union (ITU) Library & Archives Service from an original paper document in the ITU Library & Archives collections. La présente version électronique (PDF) a été numérisée par le Service de la bibliothèque et des archives de l'Union internationale des télécommunications (UIT) à partir d'un document papier original des collections de ce service. Esta versión electrónica (PDF) ha sido escaneada por el Servicio de Biblioteca y Archivos de la Unión Internacional de Telecomunicaciones (UIT) a partir de un documento impreso original de las colecciones del Servicio de Biblioteca y Archivos de la UIT. (ITU) ﻟﻼﺗﺼﺎﻻﺕ ﺍﻟﺪﻭﻟﻲ ﺍﻻﺗﺤﺎﺩ ﻓﻲ ﻭﺍﻟﻤﺤﻔﻮﻇﺎﺕ ﺍﻟﻤﻜﺘﺒﺔ ﻗﺴﻢ ﺃﺟﺮﺍﻩ ﺍﻟﻀﻮﺋﻲ ﺑﺎﻟﻤﺴﺢ ﺗﺼﻮﻳﺮ ﻧﺘﺎﺝ (PDF) ﺍﻹﻟﻜﺘﺮﻭﻧﻴﺔ ﺍﻟﻨﺴﺨﺔ ﻫﺬﻩ .ﻭﺍﻟﻤﺤﻔﻮﻇﺎﺕ ﺍﻟﻤﻜﺘﺒﺔ ﻗﺴﻢ ﻓﻲ ﺍﻟﻤﺘﻮﻓﺮﺓ ﺍﻟﻮﺛﺎﺋﻖ ﺿﻤﻦ ﺃﺻﻠﻴﺔ ﻭﺭﻗﻴﺔ ﻭﺛﻴﻘﺔ ﻣﻦ ﻧﻘﻼ ً◌ 此电子版（PDF版本）由国际电信联盟（ITU）图书馆和档案室利用存于该处的纸质文件扫描提供。 Настоящий электронный вариант (PDF) был подготовлен в библиотечно-архивной службе Международного союза электросвязи путем сканирования исходного документа в бумажной форме из библиотечно-архивной службы МСЭ. © International Telecommunication Union INTERNATIONAL TELEPHONE CONSULTATIVE COMMITTEE (C. C. I. F.) XVIIth PLENARY ASSEMBLY GENEVA, 4-12 OCTOBER, 1954 VOLUME III LINE TRANSMISSION MAINTENANCE Published by the International Telecommunication Union Geneva, 1956 INTERNATIONAL TELEPHONE CONSULTATIVE COMMITTEE (C. C. I. F.) XVIIth PLENARY ASSEMBLY GENEVA, 4-12 OCTOBER, 1954 VOLUME III LINE TRANSMISSION MAINTENANCE PAGE INTENTIONALLY LEFT BLANK PAGE LAISSEE EN BLANC INTENTIONNELLEMENT TABLE OF CONTENTS OF VOLUME III OF THE GREEN BOOK OF THE C.C.I.F. Line Transmission Maintenance Page Tables summarising the characteristics of circuits: Telephony (and telegraphy)................................................................................................... 16 Programme transm issions.......................................................................................... 18 T elevision.........................................
    [Show full text]
  • ABBREVIATIONS EBU Technical Review
    ABBREVIATIONS EBU Technical Review AbbreviationsLast updated: January 2012 720i 720 lines, interlaced scan ACATS Advisory Committee on Advanced Television 720p/50 High-definition progressively-scanned TV format Systems (USA) of 1280 x 720 pixels at 50 frames per second ACELP (MPEG-4) A Code-Excited Linear Prediction 1080i/25 High-definition interlaced TV format of ACK ACKnowledgement 1920 x 1080 pixels at 25 frames per second, i.e. ACLR Adjacent Channel Leakage Ratio 50 fields (half frames) every second ACM Adaptive Coding and Modulation 1080p/25 High-definition progressively-scanned TV format ACS Adjacent Channel Selectivity of 1920 x 1080 pixels at 25 frames per second ACT Association of Commercial Television in 1080p/50 High-definition progressively-scanned TV format Europe of 1920 x 1080 pixels at 50 frames per second http://www.acte.be 1080p/60 High-definition progressively-scanned TV format ACTS Advanced Communications Technologies and of 1920 x 1080 pixels at 60 frames per second Services AD Analogue-to-Digital AD Anno Domini (after the birth of Jesus of Nazareth) 21CN BT’s 21st Century Network AD Approved Document 2k COFDM transmission mode with around 2000 AD Audio Description carriers ADC Analogue-to-Digital Converter 3DTV 3-Dimension Television ADIP ADress In Pre-groove 3G 3rd Generation mobile communications ADM (ATM) Add/Drop Multiplexer 4G 4th Generation mobile communications ADPCM Adaptive Differential Pulse Code Modulation 3GPP 3rd Generation Partnership Project ADR Automatic Dialogue Replacement 3GPP2 3rd Generation Partnership
    [Show full text]
  • Part 2 - Condenser Testers and Testing Correctly Part1 Condenser Testers and Testing Correctly.Doc Rev
    Part 2 - Condenser Testers and Testing Correctly Part1_Condenser_Testers_And_Testing_Correctly.doc Rev. 2.0 W. Mohat 16/04/2020 By: Bill Mohat / AOMCI Western Reserve Chapter If you have read Part 1 of this Technical Series on Condensers, you will know that the overwhelming majority of your condenser failures are due to breakdown of the insulating plastic film insulating layers inside the condenser. This allows the high voltages created by the “arcing” across your breaker points to jump through holes in the insulating film, causing your ignition system to short out. These failures, unfortunately, only happen at high voltages (often 200 to 500Volts AC)….which means that the majority of “capacitor testers" and "capacitor test techniques" will NOT find this failure mode, which is the MAJORITY of the condenser failure you are likely to encounter. Bottom line is, to test a condenser COMPLETELY, you must test it in three stages: 1) Check with a ohmmeter, or a capacitance meter, to see if the condenser is shorted or not. 2) Assuming your condenser is not shorted, use a capacitance meter to make sure it has the expected VALUE of capacitance that your motor needs. 3) Assuming you pass these first two step2, you then need to test your condenser on piece of test equipment that SPECIFICALLY tests for insulation breakdown under high voltages. (As mentioned earlier, you ohmmeter and capacitance meter only put about one volt across a capacitor when testing it. You need to put perhaps 300 or 400 times that amount of voltage across the condenser, to see if it’s insulation has failed, allowing electricity to “arc across" between the metal plates when under high voltage stress.
    [Show full text]
  • An Analysis of Inertial Seisometer-Galvanometer
    NBSIR 76-1089 An Analysis of Inertial Seisdmeter-Galvanorneter Combinations D. P. Johnson and H. Matheson Mechanics Division Institute for Basic Standards National Bureau of Standards Washington, D. C. 20234 June 1976 Final U. S. DEPARTMENT OF COMMERCE NATIONAL BUREAU Of STANDARDS • TABLE OF CONTENTS Page SECTION 1 INTRODUCTION ^ 1 . 1 Background 1.2 Scope ^ 1.3 Introductory Details 2 ELECTROMAGNETIC SECTION 2 GENERAL EQUATIONS OF MOTION OF AN INERTIAL SEISMOMETER 3 2.1 Dynaniical Theory 2 2.1.1 Mechanics ^ 2.1.2 Electrodynamics 5 2.2 Choice of Coordinates ^ 2.2.1 The Coordinate of Earth Motion 7 2.2.2 The Coordinate of Bob Motion 7 2.2.3 The Electrical Coordinate 7 2.2.4 The Magnetic Coordinate 3 2.3 Condition of Constraint: Riagnet 3 2.4 The Lagrangian Function • 2.4.1 Mechanical Kinetic Energy 10 2.4.2 Electrokinetic and Electro- potential Energy H 2.4.3 Gravitational Potential Energy 12 2.4.4 Mechanical Potential Energy 13 2.5 Tne General Equations of Motion i4 2.6 The Linearized Equations of Motion 2.7 Philosophical Notes and Interpretations 18 2.8 Extension to Two Coil Systems 18 2.8.1 General 2.8.2 Equations of Motion -^9 2.8.3 Reciprocity Calibration Using the Basic Instrument 21 2.8.4 Reciprocity Calibration Using Auxiliary Calibrating Coils . 23 2.9 Application to Other Electromagnetic Transducers - SECTION 3 RESPONSE CFARACTERISTICS OF A SEISMOMETER WITH A- RESISTIVE LOAD 3.1 Introduction 3.2 Seismometer with Resistive Load II TABLE GF CONTENTS Page 3.2.1 Steady State Response 27 3.
    [Show full text]
  • Electrical & Electronics Measurement Laboratory Manual
    DEPT. OF I&E ENGG. DR, M, C. Tripathy CET, BPUT Electrical & Electronics Measurement Laboratory Manual By Dr. Madhab Chandra Tripathy Assistant Professor DEPARTMENT OF INSTRUMENTAION AND ELECTRONICS ENGINEERING COLLEGE OF ENGINEERING AND TECHNOLOGY BHUBANESWAR-751003 PAGE 1 | EXPT - 1 ELECTRICAL &ELECTRONICS MEASUREMENT LAB DEPT. OF I&E ENGG. DR, M, C. Tripathy CET, BPUT List of Experiments PCEE7204 Electrical and Electronics Measurement Lab Select any 8 experiments from the list of 10 experiments 1. Measurement of Low Resistance by Kelvin’s Double Bridge Method. 2. Measurement of Self Inductance and Capacitance using Bridges. 3. Study of Galvanometer and Determination of Sensitivity and Galvanometer Constants. 4. Calibration of Voltmeters and Ammeters using Potentiometers. 5. Testing of Energy meters (Single phase type). 6. Measurement of Iron Loss from B-H Curve by using CRO. 7. Measurement of R, L, and C using Q-meter. 8. Measurement of Power in a single phase circuit by using CTs and PTs. 9. Measurement of Power and Power Factor in a three phase AC circuit by two-wattmeter method. 10. Study of Spectrum Analyzers. PAGE 2 | EXPT - 1 ELECTRICAL &ELECTRONICS MEASUREMENT LAB DEPT. OF I&E ENGG. DR, M, C. Tripathy CET, BPUT DO’S AND DON’TS IN THE LAB DO’S:- 1. Students should carry observation notes and records completed in all aspects. 2. Correct specifications of the equipment have to be mentioned in the circuit diagram. 3. Students should be aware of the operation of equipments. 4. Students should take care of the laboratory equipments/ Instruments. 5. After completing the connections, students should get the circuits verified by the Lab Instructor.
    [Show full text]
  • Studio-Sound-1976-09
    www.americanradiohistory.com We know it helps the manufacturer to set rigid standardisation of their equipment formats - most do! It doesn't help you. The penalty need not be a sharp increase in cost We at Cadac do not expect you to suffer these short comings. Our fully modularised range of equipment leaves the flexibility of choice with you - and the cost? Lower than you would expect on a console for console comparison basis. The most versatile recording equipment in the world. S ti {'4 4 asaa+ndaliAarlf Z b 4\ a a a '` ' " {ti yE 4à4 47 ÿ4'4 ,t : :ttttp1Ñ.;v'Y+°rti , ?AA _.. t' S, A.Vfifii"4446*0é : 04 r . VOGUE P.I.P STUDIOS - FRANCE The leaders in music recording consoles and techniques. Cadac (London) Ltd. 141, Lower Luton Road Harpenden Herts. AL5 5EL 3 Harpenden (STD 05827) 643511 Telex 826323 www.americanradiohistory.com i' ITOR RAY CARTER TECHNICAL EDITOR FRANK OGDEN EDITORIAL PRODUCTION studio sound DRUSILLA DALRYMPLE :ONSULTANT HUGH FORD AND BROADCAST ENGINEERING ECUTIVE ADVERTISEMENT ANAGER For nearly ten years Dolby A has effectively been the industry standard for noise reduction; DOUGLAS G. SHUARD other systems, despite their merits, amounted to opposition rather than competition. However, ADVERTISEMENT MANAGER more tracks and greater use of ping -pong within the rest of the recording chain now TONY NEWMAN pressurises studios into overriding the wishes of their accountants by obtaining a double kDVERTISEMENT REPRESENTATIVE inventory of noise reduction equipment. And of course the force for change is aided, as always, PHYLLIS BIRCH by the persistent technological rhetoric of those who have something to sell to those who haven't yet bought their quota; but that's life.
    [Show full text]
  • Manual S/N Prefix 11
    HP Archive This vintage Hewlett Packard document was preserved and distributed by www. hparchive.com Please visit us on the web ! On-line curator: Glenn Robb This document is for FREE distribution only! OPERATING AND SERVICING MANUAL FOR MODEL 475B TUNABLE BOLOMETER MOUNT Serial 11 and Above Copyright 1956 by Hewlett-Packard Company The information contained in this booklet is intended for the operation and main· tenance oC Hewlett-Packard equipment and is not to be used otherwise or reproduced without the written consent of the Hewlett­ Packard Company. HEWLETT-PACKARD COMPANY 275 PAGE MILL ROAD, PALO ALTO, CALIFORNIA, U. S. A. 475BOOl-1 SPECIFICATIONS FREQUENCY RANGE: Approximately 1000 - 4000 MC (varies with SWR and phase of source and value of bolometer load.) POWER RANGE: 0.1 to 10 milliwatts (with -hp- Model 430C Microwave Power Meter.) FITTINGS: Input Connector - Type N female (UG 23/U). Output Connector (bolometer dc connec­ tion) - Type BNC (UG 89/U). Type N Male Connector (UG 21/U) sup­ plied to replace bolometer connector so that mount may be used as a conven­ tional double -stub transformer. POWER SENSITIVE ELEMENT: Selected 1/100 ampere instrument fuse. Sperry 821 or Narda N821 Barretter. Western Electric Type D166382 Ther­ mistor. OVERALL DIMENSIONS: 1811 long x 7-3/8" wide x 3-5/811 deep. WEIGHT: 8 pounds. ...... ...... Pl ::l P. Pl 0-' o <: Cil >+>­ -J lJ1 lJj o o ...... ......I • OPERATING INSTRUC TIONS INSPECTION This instrument has been thoroughly tested and inspected before being shipped and is ready for use when received. After the instrument is unpacked, it should be carefully inspected for any damage received in transit.
    [Show full text]
  • (Ohmmeter). Aims: • Calibrating of a Sensitive Galvanometer for Measuring a Resistance
    Exp ( ) Calibrating of a sensitive galvanometer for measuring a resistance (Ohmmeter). Aims: • Calibrating of a sensitive galvanometer for measuring a resistance. The theory When a galvanometer is used as an ohmmeter for measuring an ohmic resistance R, the deviation angle θ of the galvanometer’s coil is directly proportional to the flowing current through the coil and inversely proportional to the value of the resistance. The deviation will reach to the maximum end when the resistance equals to zero or the current has the maximum value. For this reason, the scale will be divide by inversely way in comparison with the ammeter and the voltmeter. The original circuit as shown in Fig(1) consists of a dry cell(E) , rheostat and ammeter (A) are connected in series with small resistor s has the range of 1 omega. The two terminals of “s” are connected in parallel to another combination includes a sensitive galvanometer “G” which has internal resistance “r” and a resistors box “R”, this combination is called the measuring circuit. When the value of R equals zero, and by moving the rheostat in the original circuit, it is possible to set the flowing electric current in measuring the circuit as a maximum value od deviation in the galvanometer. By assigning different values of R, the deviation θ is decreasing with increasing the value of R or by another meaning when the flowing current through the galvanometer decreases. Therefore, the current through the galvanometer is inversely proportional to the value of R according the following Figure 1: Ohmmeter Circuit diagram equation; V=I(R+r) R=V/I-r or R=V/θ-r 1 | P a g e This is a straight-line equation between R and (1/θ) as shown in Fig(2).
    [Show full text]
  • Ballastic Galvanometer This Is a Sophisticated Instrument. This
    Ballastic galvanometer This is a sophisticated instrument. This works on the principle of PMMC meter. The only difference is the type of suspension is used for this meter. Lamp and glass scale method is used to obtain the deflection. A small mirror is attached to the moving system. Phosphorous bronze wire is used for suspension. When the D.C. voltage is applied to the terminals of moving coil, current flows through it. When a current carrying coil kept in the magnetic field, produced by permanent magnet, it experiences a force. The coil deflects and mirror deflects. The light spot on the glass scale also move. This deflection is proportional to the current through the coil. Q i = , Q = it = idt t Q , deflection Charge Fig 2.27 Ballastic galvanometer Measurements of flux and flux density (Method of reversal) D.C. voltage is applied to the electromagnet through a variable resistance R1 and a reversing switch. The voltage applied to the toroid can be reversed by changing the switch from position 2 to position ‘1’. Let the switch be in position ‘2’ initially. A constant current flows through the toroid and a constant flux is established in the core of the magnet. A search coil of few turns is provided on the toroid. The B.G. is connected to the search coil through a current limiting resistance. When it is required to measure the flux, the switch is changed from position ‘2’ to position ‘1’. Hence the flux reduced to zero and it starts increasing in the reverse direction. The flux goes from + to - , in time ‘t’ second.
    [Show full text]
  • Massachusetts Institute of Technology Department of Electrical Engineering and Computer Science
    Massachusetts Institute of Technology Department of Electrical Engineering and Computer Science 6.002 - Circuits and Electronics Fall 2004 Lab Equipment Handout (Handout F04-009) Prepared by Iahn Cajigas González (EECS '02) Updated by Ben Walker (EECS ’03) in September, 2003 This handout is intended to provide a brief technical overview of the lab instruments which we will be using in 6.002: the oscilloscope, multimeter, function generator, and the protoboard. It incorporates much of the material found in the individual instrument manuals, while including some background information as to how each of the instruments work. The goal of this handout is to serve as a reference of common lab procedures and terminology, while trying to build technical intuition about each instrument's functionality and familiarizing students with their use. Students with previous lab experience might find it helpful to simply skim over the handout and focus only on unfamiliar sections and terminology. THE OSCILLOSCOPE The oscilloscope is an electronic instrument based on the cathode ray tube (CRT) – not unlike the picture tube of a television set – which is capable of generating a graph of an input signal versus a second variable. In most applications the vertical (Y) axis represents voltage and the horizontal (X) axis represents time (although other configurations are possible). Essentially, the oscilloscope consists of four main parts: an electron gun, a time-base generator (that serves as a clock), two sets of deflection plates used to steer the electron beam, and a phosphorescent screen which lights up when struck by electrons. The electron gun, deflection plates, and the phosphorescent screen are all enclosed by a glass envelope which has been sealed and evacuated.
    [Show full text]