KROHNHITE 4402B OPS 电路图.pdf

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1、Model 4402B Ultra-Pure Sinewave Oscillator 1Hz to 110kHz Typical Distortion of 0.0005% Serial No. _ Operating Manual 15 Jonathan Drive, Unit 4, Brockton, MA 02301 U.S.A. Tel: (508) 580-1660; Fax: (508) 583-8989 www.krohn-; infokrohn- Copyright 2003 Krohn-Hite Corporation. All rights reserved. Conten

2、ts of this publication may not be reproduced in any form without the written permission of Krohn-Hite Corporation. Printed in USA - 4/03. RadioFans.CN 收音机爱 好者资料库 RadioFans.CN 收音机爱 好者资料库 TABLE OF CONTENTS SECTION 1 . . . GENERAL DESCRIPTION . . . . . . . . . . . . 1-1 1.1 . . . . . INTRODUCTION . . .

3、 . . . . . . . . . . . . . . . . . . 1-1 1.2 . . . . . SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . 1-1 1.2.1 . . FREQUENCY . . . . . . . . . . . . . . . . . . . . . . . 1-1 1.2.2 . . MAIN OUTPUTS . . . . . . . . . . . . . . . . . . . . . 1-2 1.2.3 . . FIXED OUTPUT . . . . . . . . . . . .

4、. . . . . . . . . 1-2 1.2.4 . . QUADRATURE OUTPUT. . . . . . . . . . . . . . . . 1-3 1.2.5 . . GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 1.2.6 . . OPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 SECTION 2 . . . OPERATION . . . . . . . . . . . . . . . . . . . . . 2

5、-1 2.1 . . . . . POWER REQUIREMENTS . . . . . . . . . . . . . . . 2-1 2.2 . . . . . OPERATING CONTROLS AND CONNECTORS . 2-2 2.2.1 . . REAR PANEL . . . . . . . . . . . . . . . . . . . . . . . 2-2 2.3 . . . . . OPERATION . . . . . . . . . . . . . . . . . . . . . . . . 2-3 2.3.1 . . FREQUENCY CONTROL .

6、 . . . . . . . . . . . . . . . 2-3 2.3.2 . . AMPLITUDE CONTROL . . . . . . . . . . . . . . . . 2-3 2.3.3 . . FLOATING GROUND . . . . . . . . . . . . . . . . . . 2-3 SECTION 3 . . . INCOMING ACCEPTANCE . . . . . . . . . . . . 3-1 3.1 . . . . . INTRODUCTION . . . . . . . . . . . . . . . . . . . . . 3-

7、1 3.2 . . . . . LIST OF EQUIPMENT REQUIRED . . . . . . . . . 3-1 3.3 . . . . . PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . 3-2 3.3.1 . . DC LEVEL ADJUSTMENTS . . . . . . . . . . . . . . 3-2 3.3.2 . . FREQUENCY ACCURACY . . . . . . . . . . . . . . 3-2 3.3.3 . . MAIN OUTPUT AMPLITUDE. . .

8、. . . . . . . . . . 3-2 3.3.4 . . AMPLITUDE FLATNESS. . . . . . . . . . . . . . . . 3-3 3.3.5 . . OUTPUT DISTORTION . . . . . . . . . . . . . . . . . 3-3 SECTION 4 . . . CIRCUIT DESCRIPTION . . . . . . . . . . . . . 4-1 4.1 . . . . . THEORY OF OPERATION . . . . . . . . . . . . . . . 4-1 4.2 . . . .

9、. AVC OPERATION . . . . . . . . . . . . . . . . . . . . 4-2 Table of Contents - i Table of Contents RadioFans.CN 收音机爱 好者资料库 FIGURES Section 1 Figure 1.1 . Typical Output Distortion . . . . . . . . . . . . . . . 1-3 Section 2 Figure 2.1 . Operating Controls and Connectors . . . . . . . . . 2-1 Sectio

10、n 3 Figure 3.1 . Test Set-Up for Measuring Amplitude Flatness. . 3-2 Section 4 Figure 4.1 . Model 4402B Simplified Block Diagram . . . . . . 4-1 Figure 4.2 . Simplified AVC Diagram . . . . . . . . . . . . . . . . 4-2 Section 5 Figure 5.1A. . Troubleshooting Flowchart. . . . . . . . . . . . . 5-3 Fig

11、ure 5.1B . . Troubleshooting Flowchart. . . . . . . . . . . . . 5-4 ii - Table of Contents Model 4402B Ultra-Pure Sinewave Oscillator iii - Table of Contents Model 4402B Ultra-Pure Sinewave Oscillator Model 4402BSinewave Oscillator This page intentionally left blank. iv - Table of Contents Model 440

12、2B Ultra-Pure Sinewave Oscillator SECTION 1 GENERAL DESCRIPTION 1.1INTRODUCTION The Model 4402B is an ultra-pure sinewave, stable amplitude oscillator designed to meet the needs of to- days high precision 16 to 18 bit A/D converter testing, and audio test and measurement technology. Covering the fre

13、quency range from 1Hz to 110kHz, with precise 3 digit frequency tuning, the 4402B pro- duces a virtually “distortion-free” (0.0005%) sinewave for measuring A/D converter accuracy, audio preamplifier and power amplifier harmonic distortion. With its exceptionally flat response (0.02dB), the 4402B eli

14、minates the need to constantly monitor voltage levels, during frequency response tests. The4402Bprovidesa7Vrmssinewaveoutput,(balancedoutput,14Vrmsend-to-end),3.5Vrmsinto50 ohms, and has no loss in performance when loaded with a linear 50 ohm load. A3-position,push-buttonattenuatorcalibratedin20dBst

15、eps,alongwiththea30dBvernier,providesa total dynamic range of 90dB. Simultaneous fixed and quadrature (90) outputs are provided. Each output is 7Vrms with 600 ohm source impedance. The 4402B is the perfect addition to your present test and/or precision measurement set-up. 1.2SPECIFICATIONS The follo

16、wing specifications apply to the Main, Quadrature and Fixed Outputs, except where noted. 1.2.1 FREQUENCY Range: 1Hz to 110kHz. Accuracy: 0.5% of frequency setting. Control: 2 digits of frequency, calibrated in 1Hz and 0.1Hz steps, with a calibrated vernier providing continuous coverage between the 0

17、.1Hzsteps, plus a5decade push-button multiplier withoverlapping ranges. Stability: Vs. Time: 0.01% in 1 hour or less. Vs. Temperature: 0.05%/C. Vs. Line: 0.001% for a 10% change in line voltage. General Description - 1-1 General Description - Section 1 1.2.2 MAIN OUTPUTS MaximumAmplitude:7Vrmsopenci

18、rcuit(balancedoutput,14Vrmsend-to-end);3.5Vrms;+48dBm into 50 ohm load (balanced output, 7V rms end-to-end). Impedance: Constant 50 ohms. Maximum Current: 75mArms. Minimum Amplitude: 0.2mV. Amplitude Flatness: 0.02dB, 1Hz to 110kHz. Amplitude Stability: Vs. Time: 0.01% in 1 hour or less. Vs. Tempera

19、ture: 0.05%/C. Vs. Line: 0.001% for a 10% change in line voltage. Amplitude Control: A4-position push-button attenuator calibrated in20dBsteps from0dBto60dB, Accuracy,0.25dB/20dBstep;Voltsrmscontrolwithgreaterthan30dBofcoveragecalibratedinvolts. Accuracy: 20% of setting. Main Output Distortion: Freq

20、uencyDistortion %Distortion (dB) 1Hz to 10kHz0.0005106 10kHz to 20kHz0.001895 20kHz to 50kHz0.005685 50kHz to 110kHz9, and provides additional resolution between the 0.1Hz steps. The 5-band push-button multiplier is calibrated in decade steps from x1 to x10k. MultiplierFrequency Range x11.00Hz to 11

21、Hz x1010.0Hz to 110Hz x100100Hz to 1.1kHz x1k1.00kHz to 11kHz x10k10.0kHz to 110kHz 2.3.2 AMPLITUDE CONTROL TheMainOutputcontroliscontrolledbya4-positionpush-buttonattenuator;andasingleturnvari- ablecontrol.Theattenuatoriscalibratedin20dBstepsfrom0dBto60dB.TheVOLTSRMScontrol is calibrated in volts a

22、nd provides an additional 30dB coverage on each attenuator position. Attenuator Volts RMS Range (Main Output) 0dB220mV to 7V 20dB22mV to 700mV 40dB2mV to 70mV 60dB220V to 7mV To optimize the resolution of the adjustment, use the lower of the two attenuator settings (e.g. if the ap- plication require

23、s a 500mV rms signal, use the 20dB setting rather than the 0dB setting). The Quad (90) and Fixed (180 out of phase from top Main Output BNC) outputs are fixed at 7Vrms. The output impedance of each of these outputs is 600 ohms. 2.3.3 FLOATING GROUND TheCIRCUITGROUNDswitchontherearpanelallowstheoscil

24、latorto“float”orisolatetheoscillator circuit or signal ground from the chassis or earth ground. Maximum allowable DC isolation is 100V. Operation - 2-3 Operation - Section - 2 This page intentionally left blank. 2-4 - Operation Model 4402B Ultra-Pure Sinewave Oscillator SECTION 3 INCOMING ACCEPTANCE

25、 3.1INTRODUCTION The following procedure should be used to verify the oscillator is operating within specifications, both forincominginspectionandroutineservicing.Testsshouldbemadewiththecoverinplace,andthepro- cedure given belowshould befollowedinsequence. Familiarize yourself withthe set-up andope

26、rating procedures outlined in Section 2, Operation. 3.2LIST OF EQUIPMENT REQUIRED 1.Oscilloscope: bandwidth of at least 1MHz, vertical sensitivity 10mV/cm, ac/dc coupled. 2.DC Voltmeter: 0V to 15V. 3.AC Voltmeter: Frequency range 110kHz, to measure between 0V and 7Vrms, better than 3% accuracy. 4.RM

27、S Voltmeter for Measuring Amplitude Flatness: Able to measure ac voltage variations of 0.02dB (0.23%) from 10Hz to 110kHz. orHigh Frequency Thermal Converter: Fluke Model A55 and either a DC Differential Voltmeter (FlukeModel895A),oraDCNullDetector(FlukeModel845A)withastable,DCreferencesup- ply. 5.S

28、pectrum Analyzer: Able to measure harmonic components below 0.0005% (106dB). 6.Frequency/Period Counter: Accuracy better than 0.5%, 1Hz to 110kHz. Incoming Acceptance - 3-1 Incoming Acceptance - Section 3 Thecoveroftheunitshouldnotberemovedwhenthein- strumentisconnectedtoanacpowersource,becauseof po

29、tentiallydangerousvoltagesthatexistwithintheunit. CAUTION! 3.3PROCEDURE Allow the Model 4402B to warm-up for at least 30 minutes, then set the controls on the front and rear panels to the following positions: Frequency Hz: 1kHz (1-0-0 x1k). Amplitude: 0dB, Volts RMS set for maximum clockwise (CW). C

30、ircuit Ground: Chassis. 3.3.1 DC LEVEL ADJUSTMENTS Connect the DVM to the Main Output and adjust the rear panel screwdriver control marked “MAIN OUTPUT DC LEVEL” (adjusts the dc level for the top Main Output BNC connector) for a reading of 0V. Repeat the same for the bottom Main Output marked on the

31、 rear panel “MAIN OUTPUT DC LEVEL”. 3.3.2 FREQUENCY ACCURACY ConnectthefrequencycountertoeitherMainOutput.Verifythatthefrequencyaccuracyiswithin0.5% of the FREQUENCYHz setting between 1Hz and 110kHz. 3.3.3 MAIN OUTPUT AMPLITUDE Setthe4402Bfrequencyto1kHz(1-0-0X1k).ConnecttheACVMtotheMainOutput;witht

32、heVOLTS RMScontrolsettomaximumCW,theMainOutputshouldbe?7Vrms.RotatetheVOLTSRMScontrol to minimum (counter clockwise, CCW), the Main Output should be 220mV. Turn the VOLTS RMS clockwisetoobtainareadingof7Vrms.Connecta50ohmresistor 1%acrossthetopBNCoftheMain Output; the voltage should drop to 3.5Vrms.

33、 Repeat the same for the bottom BNC at the Main Output. Remove the 50?terminator. Tochecktheattenuatoraccuracy,adjusttheVOLTSRMScontrolforanACVMreadingof7Vrms.Ver- ify that the attenuation accuracy is within 0.25dB (2.9%) per 20dB step. ConnecttheACVMtotheFIXEDOUTPUT.TheACVMshouldread?7Vrms.Connecta

34、600ohmload (1%) across the FIXED OUTPUT; the amplitude should drop the value. Repeat the same for the QUAD OUTPUT. 3-2 - Incoming Acceptance Model 4402B Ultra-Pure Sinewave Oscillator Figure 3.1 Test Set-Up for Measuring Amplitude Flatness 3.3.4 AMPLITUDE FLATNESS (see set-up on next page) Amplitude

35、flatnessisdefinedasthemaximumdeviationfromconstantamplitudeexpressedindBor% over a specified frequency range. Since few ac voltmeters are capable of accurately measuring voltage deviations 0.02dB (0.23%) up to 100kHz, the use of a high frequency thermal converter, and either a differentialdcvoltmete

36、rordcnullmeterwithacalibratedorstabledcsupply,isrecommended(seeFig- ure 3.1). Minimize the capacitance in the meter leads to avoid loading effects at the higher frequencies. SetthefrequencyoftheModel4402Btoareferencefrequencyof1kHzandadjustthevoltmeterornull meter for a 0dB/0% deviation. Tune the os

37、cillator frequency from 10Hz to 110kHz. The Main Output should remain constant within 0.02dB (0.23%) over the entire frequency range. Repeat this procedure for both Main Outputs and the Fixed Output. Repeat for the Quad Output, toler- ance, 2dB (2.5%). 3.3.5 OUTPUT DISTORTION The use of a spectrum o

38、r wave analyzer (HP, B&K, Marconi, etc.) and a pre-filter is recommended for distortion measurements below 0.001%. The pre-filter consists of a passive “twin-tee” or notch filter, andisusedtoattenuatethefundamentalfrequencyinordertoincreasethesensitivityofthespectrumor wave analyzer. Component Value

39、s:R = 7.96k, 1% Center Frequency (Hz)1001k10k Capacitance (F)*0.10.010.001 * Capacitance values are 1% tolerance Incoming Acceptance - 3-3 Incoming Acceptance - Section 3 The diagram below shows the test set-up for measuring the output distortion of the 4402B. To measure distortion, proceed as follo

40、ws: 1.Set the controls on the analyzer to the following initial positions: ADAPTIVE SWEEPOff DISPLAYClear Write FREQUENCY1kHz AMPLITUDE MODELog dB/Div AMPLITUDE REFERENCE LEVEL0 (Zero) INPUT SENSITIVITY+20dB (10V) RESOLUTION BANDWIDTH100Hz FREQUENCY SPAN/DIV0.5Hz SWEEP TIME/DIV1Sec SWEEP MODERepetit

41、ive 2.Set switch S1 to the “INPUT” position. Adjust the 4402B frequency to correspond to the “twin-tee” null frequency. 3.Adjust the INPUT SENSITIVITYvernier on the analyzer to obtain a 0dB reference at the funda- mental frequency. 4.Switch S1 to the “OUTPUT”position. Adjust the frequency of the 440

42、2B to null the fundamental frequency.Itmaybenecessarytomakefineadjustmentstothe“twin-tee”componentvaluestoob- tain sufficient null of the fundamental. 5.Increase the INPUT SENSITIVITY in dB steps until the harmonic components are visible. ThedBlevelofeachharmoniccomponentisthesumofthedBbelowthe0dBre

43、ferencelevelonthedis- play, plus the change in the INPUT SENSITIVITY level, in dB. To compensate for loss through the “twin-tee” filter, add +9dB to the second harmonic component and +5dB to the 3rd harmonic component. For example, if the second harmonic is 128dB: 128dB +9dB = 119dB. The total harmo

44、nic distortion may then be calculated as follows: T H D dB ndrdnth . .()logloglog.log? ? 20 12 10 13 10 1 10 Since: log ( ) log( ) ( )? ? 1 1 10 x x x T H D dB dBnddBrddBth . .()log(.?10101010 2 10 3 10 4 10 10 10 dBnth ) T H D dB dBn . .()log()? ? 1010 10 dBn = sum of all harmonics 3-4 - Incoming A

45、cceptance Model 4402B Ultra-Pure Sinewave Oscillator Example: 2nd harmonic = -40dB 3rd harmonic = -46dB 4th harmonic = -50dB T H D. .log() log( ? ? ? ? 10101010 10101 40 10 46 10 50 10 4 010 101002510 10135 103 4 65? ? ? ? ? ? . ) log(_) log() . ? ? 87 387 10100 116 38 7 20 ? ? ? ? ? . %() %. . dB Incoming Acceptance - 3-5 Incoming Acceptance - Section 3 This page intentionally left blank. 3-6 - Incoming Acceptance Model 4402B Ultra-Pure Sinewave Oscillator