HP-205A-Manual-SNP-953 电路图.pdf

HP Archive This vintage Hewlett Packard document was preserved and distributed by www. Please visit us on the web ! Thanks to on-line curator: Joe Geller RadioFans.CN 收音机爱 好者资料库 OPERAtiNG AND 5tHVIl;t MANUAL H P PART NO. 00205-90010 AUDIO SIGNAL GENERATOR MODELS 205A AND 205AG COVERS ALL SERIALS HEWLETTlliPACKARD RadioFans.CN 收音机爱 好者资料库 OPERATING AND SERVICE MANUAl HP PART NO. 00205- 90010 AUDIO SIGNAL GENERATOR MODELS 205A AND 205AG COVERS ALL SERIALS Manual for Serials Prefixed: 953 Manual Changes for Serials 0953A 11577 and above Manual Backdating Changes (Appendix C) for Serials Prefixed: 953, 246-, 231,151,024-,012 and Serials 8462 and below (205A) Copyright Hewlett-Packard Company 1955 P.O. Box 301, Loveland, Colorado, 80537 U.S.A. Printed: DEC 1970 RadioFans.CN 收音机爱 好者资料库 Table of Contents Model205AG TABLE OF CONTENTS Section Page Section Page GENERAL INFORMATION 1-1 5-14. Dial Accuracy 5-1 I-I. Description 1-1 5-18. Output Flatness 5-2 1-3. Instrument Specifications and 5-26. Distortion 5-2 General Information I-I 5-30. Hum Level , 5-2 1-5. Instrument and Manual Identification 1-1 5-39. Output Attenuator Accuracy Check 5-2 Section Page 5-56. Input Meter Check 54 II INSTALLATION 2-1 5-63. Input Attenuator Accuracy 54 2-1. Introduction 2-1 5-73. Adjustment Procedure 5-5 2-3. Inspection 2-1 5-74. Frequency Calibration Adjustment 5-5 2-5. Power Requirements 2-1 5-82. Output Level Meter Adjustment : 5-5 2-7. Grounding Requirements 2-1 5-85. Input Level Meter Adjustment 5-8 2-10. Rack/Bench Installation 2-1 5-90. Troubleshooting 5-8 2-12. Repackaging for Shipment 2-1 5-91 . Distortion 5-8 5-93. Intermittent Output 5-8 Section Page 5-96. Repair Procedures 5-8 III OPERATING INSTRUCTIONS 3-1 5-97. Cabinet Removal 5-8 3-1. Introduction 3-1 5-99. Tube Replacement 5-9 3-3. Panel Features 3-1 5-101. Capacitor Drive Lubrication 5-9 3-5. Preliminary Checks 3-1 5-103. Replacement of Lamp Rll 5-9 3-7. Operating Instructions 3-1 3-8. Oscillator Operation 3-1 Section Page 3-10. Output Level Meter Operation 3-1 VI REPLACEABLE PARTS 6-1 3-15. Input Level Meter Operation 34 6-1. Introduction 6-1 64. Ordering Information 6-1 Section Page 6-6. Non-Listed Parts 6-1 IV THEORY OF OPERATION 4-1 4-1. General 4-1 Section Page VII CIRCUIT DIAGRAMS 7-1 Section Page 7-1. Introduction 7-1 V MAINTENANCE 5-1 5-1. Introduction 5-1 APPENDICES 5-3. Required Test Equipment 5-1 A. CODE LIST OF MANUFACTURERS 5-5. Performance Checks 5-1 B. SALES AND SERVICE OFFICES 5-7. Frequency Range 5-1 C. MANUAL BACKDATING CHANGES LIST OF TABLES Nm Pa Number Page I-I. Specifications 1.Q 5-1. Required Test Equipment 5.Q 1-2. General Information : 1.Q 5-2. Dial Accuracy Check 5-1 3-1. Output Meter Voltage 5-3. Factory Selected Components 5-8 Multiplying Factor 3-1 54. Troubleshooting Chart 5-9/5-10 3-2. Input Meter Voltage Multiplying Factor 34 6-1. Replaceable Parts 6-2 III Model205AG Table of Contents ) Number I-I. Model 205 AG Audio Signal Generator 3-1. Model 205AG Panel Features 3-2. Output Voltage Correction Factors When Using Output Attenuators 3-3. Input Level Meter Correction Curve 4-1. Block Diagram Model 205AG LIST 0 FILL USTRATI 0NS Page Number Page 5-1. Logarithmic Addition of I-I Hum Harmonics 5-3 3-2 5-2. I dB Attenuator Accuracy Check 54 5-3. Adjustments and Chassis Component 3-3 Location (Top View) 54. Adjustments and Chassis Component 5-6 Location (Bottom View) 5-7 34 7-1. Model 205AG Audio Signai Generator Circuit 4-1 and AllA2 Component Locator 7-3 iv Section I Model205AG Table 1-1. Specifications Frequency R3nge: 20 Hz 10 20 kHz in three decade bands: Xl 20 Hz to 200 Hz XIO 200 Hz to 2 kHz XI00 2 kHz to 20 kHz Calibration covers approximately 270 degrees on 6 inch diameter main dial. Dial Accuracy: WitlUn 2k of setting at normal ambient tempera tures. (Includes warm-up and changes due to aging of tubes and components.) Output Flatness: 1.5 dB 20 Hz to 20 kHz at output levels; 30 dBm with output meter reading held at +37 dB (refer ence =1000 Hz) 1 dB 20 Hz to 20,kHz at output levels 1,11 10 INPUT ATIENUATOR (DB) This switch is the range switch for the INPUT LEVEL meter and is calibrated in steps of 5 dB from 0 to 40 dB. POWER ON This switch controls the power supplied to the instrument from the power line. FREQUENCY RANGE The position of this switch indicates the multiply ing factor to be used with the frequency dial indication. CD FREQUENCY VERNIER Permits fme tuning of the FREQUENCY dial. AMPLITUDE The control adjusts the amplitude of oscillator voltage applied to the output amplifier. The calibration is in arbitrary units. LOAD ON This switch is used to connect an internal 600 ohm load across the OUTPUT terminals. IMPEDANCE This switch selects the instrument output imped ance. The available impedances are 50, 200, 600, and 5000 ohms. CD OUTPUT The instrument output appears at four terminals. The terminal marked CT is the center tap of the line matching transformer. The -4-terminal is connected to the chassis. The two vertically spaced terminals are connected to the line matching transformer through the IMPEDANCE switch. A balanced output is obtained from the vertically spaced terminals and an unbalanced output may be obtained by connecting the terminal to one of the output terminals with the captive link provided. I dB ATTENUATOR Attenuates output in 10 steps of 1 dB each. 10 dB ATIENUATOR Attenuates output in 10 steps of 10 dB each. . FREQUENCY Dial This dial is calibrated in Hz. The output frequency is the frequency dial indication multiplied by the FREQUENCY RANGE switch position. Figure 3-1. Model 205AG Panel Features 3-2 Model205AG Section III POWER Indicator Light Illuminates when line switch is ON, indicating primary power has been applied to the instrument. OUTPUT LEVEL This meter indicates the voltage at the output terminals when the IMPEDANCE switch is set at 600, output attenuators both at zero, and the instrument is loaded with the internal or an external 600 ohm load. Under other operating conditions the meter may be used as a monitor to insure constant output voltage. INPUT LEVEL This meter measures the voHage applied to the input terminals and the range of the meter is controlled by the INPUT ATTENUATOR (DB) range switch. INPUT These terminals are the input for the audio frequency INPUT LEVEL vacuum tube voltmeter in the instrument. FUSE The fuseholder, located on the back of the chassis, contains the power line fuse. Refer to the Table of Replaceable Parts (6-1) for the correct fuse rating. PRIMARY POWER RECEPTACLE Connects primary power to the instrument. 115 V1230 V Slide SWitch S6 selects nominal operating voltage of the instru ment. PIO Figure 3-1. 0 10 20 30 CD a I 40 z 0 t50 z I.lJ 60 t- t a. t 80 : 0 90 100 110 I I I I !I , - , , .000001 .00001 .0001 .001 .01 .1 OUTPUT M ETER VOLTAGE MULTI PLYI NG FACTOR FOR 600 OHM LOAD Figure 3-2. Output Voltage Correction Factors When Using Output Attenuators Model 20SAG Panel Features 20AG-8-Z3IJ 3-3 Section III 3-15. INPUT LEVEL METER OPERATION. 3-16. The Input Level meter is an independent audio frequency vacuum tube voltmeter, suitable for monitoring the output voltage of a device under test. The meter is calibrated in volts and dB above 1 milliwatt in 600 ohms when the INPUT ATTENUATOR (DB) switch is on zero. 3-17. When making comparative measurements across a constant impedance the meter and INPUT ATTENUATOR (DB) switch will indicate directly the change in dB in the circuit under test. 3-18. When using the Input Level meter to monitor a 600 ohm circuit, the power level in dB above 1 milliwatt is equal to the meter indication plus the indication of the INPUT ATTENUATOR (DB) switch. 3-19. When making power measurements in circuits with impedances below 600 ohms, the absolute level in dB abovel or below 1 milliwatt is equal to the level indicated on the meter plus the INPUT ATPENUATOR (DB) switch indica tion plus a correction factor for the circuit impedance. +30 CD 0 I Z 0 I U W a: a: 0 +20 u a: w I W I : z +10 o I 10 Model205AG Figure 3-3 gives correction factors for impedances between 1 and 600 ohms. 3-20. The input voltage level for any range of the INPUT ATTENUATOR (DB) switch is the voltage indicated by the Input Level meter multiplied by the factor indicated in Table 3-2 for the particular range of the INPUT ATTENU ATOR (DB) switch in use. Table 3-2. Input Meter Voltage Multiplying Factor INPUT ATTENUATOR Meter Voltage (DB) Position Multiplying Factor 0 5 10 15 20 25 30 35 40 1 1.78 3.16 5.62 10 17.78 31.62 56.23 100 I I I , I , , I I I lIl,. r. ill. I . I , I I ,I , . . I I . . , . . . I I I , , ! I . I I I. . . 100 1000 1M PEDANCE-OHMS G -. -63 Figure 3-3. Input Level Meter Correction Curve 34 Model205AG Section IV SECTION IV THEORY OF 4- 1. GENERAL. 4-2. The Model 205AG Audio Signal Generator consists of an oscillator, an amplifier, output meter and attenuator, line matching transformer, and a conventional power supply (see Figure 4-1). 4-3. The oscillator section (tubes VI and V2) is a resist ance-tuned type circuit. Basically, this oscillator is a two-stage resistance-eoupled amplifier which is caused to oscillate by the use of a positive feedback network. This network is a frequency-selective resistance-eapacity combin ation which controls the frequency of oscillation. By using a variable tuning capacitor for the capacity of the network, it is possible to tune the oscillator over a wide 10: 1 range; and by using a sWitching arrangement to select different values of resistance for the network, several ranges are given to the oscillator. 44. Negative feedback is used in the oscillator section in order to minimize distortion and to obtain a very high order of stability. The amount of negative feedback is determined by a resistance network, one element of which is non-linear (the 3-watt lamp in the cathode of VI). This element controls the amount of feedback in accordance with the amplitude of oscillation and consequently main tains the amplitude of oscillation substantially constant OPERATION over a wide frequency range. The negative feedback also keeps the operation of the system on the linear portion of the tube characteristic. 4-5. The amplifier section consists of a voltage amplifier tube directly coupled to a phase inverter which drives the push-pull output tubes. The tertiary winding on the output transformer provides negative feedback for the amplifier. 4-6. The output meter and attenuator section is made up of an average reading type voltmeter and two bridged T-type attenuators. The attenuators and voltmeter are connected between the output transformer secondary and the primary of the line matching transformer. 4-7. A fullwave rectifier and a dc milliammeter calibrated in volts and decibels make up the Output Level meter. The line matching transformer is used to change the 500 ohms line impedance to 50, 200, 600, or 5,000 ohms output impedance. 4-8. The Model 205AG also includes an Input Level meter which is of the average responding type. The meter consists of a two stage amplifier with negative feedback, a full-wave rectifier and a dc milliammeter calibrated in volts and decibels. NEGATIVE FEEDBACK r-l II OUTPUT LEVEL METER TUBE V7 METER Ml Figure 4-1. Block Diagram Model 205AG 4-1 Section V Model205AG Table 5-1. Required Test Equipment INSTRUMENT TYPE REQUIRED CHARACTERISTICS RECOMMENDED MODEL Electronic Counter Frequency Range: 20 kHz -hp-Model 5245L Electronic Counter I AC Voltmeter Frequency Range: 20 Hz to 20 kHz Accuracy: 1% of full scale 1% of reading. -hp- Model 400 FL AC Voltmeter I Wave Analyzer Frequency Range: 20 Hz to 20 kHz. Dynamic Range: 75 dB (should be able to measure levels of -90 dBm) -hp- Model 302A Wave Analyzer Attenuator Frequency Range: 0 Hz to 20 kHz Attenuation Range: 10 dB in 1 dB steps OveralJ Accuracy: 0.1 dB -hp- Model 355C Attenuator Resistor Approximately son at 1/4 watt -hp- Part No. 0698-4110 I 5() Model205AG Section V SECTIOI V MAINTENANCE 5-1. INTRODUCTION. 5-2. This section contains maintenance and service infor mation for the -hp-Model 205AG Audio Oscillator. Included are performance checks, adjustment procedures, troubleshooting, and repair procedures. 5-3. REQUIRED TEST EQUIPMENIT. 5-4. The eqUipment needed to properly check and adjust the Model 205AG is listed in Table 5-1. If the recommend ed model is not available, any instrument that has specifica tions equal to or better than the required specifications may be used. 5-5. PERFORMANCE CHECKS. 5-6. Performance checks are in-eabinet tests that compare the Model 205AG with its given specifications. These checks may be used for incoming inspection, periodic maintenance, and for specification checks after a repair. A Performance Check Test Card is prOVided at the end of this section for recording the performance of the instrument during the performance checks. The card may be removed from the manual and used as a permanent record of the incoming inspection or of a routine performance check. If the instrument fails to meet a specification refer to the adjustment and troubleshooting procedures in the last half of this section. Before these checks are attempted the instrument should be turned on according to the procedure outlined in Paragraphs 3-5 thru 3-7 of this manual. 5-7. FREQUENCY RAIlGE. Specification 20 Hzto20 kHz If instrument does not meet this specification refer to Paragraph 5-74. 5-8. Set power switch to ON. 5-9. Set Model 205AG controls as follows: 10 and 1 dB OUTPUT ATTENUATORS OdB FREQUENCY RANGE Xl LOAD ON IMPEDANCE 600n AMPLITUDE .1 00 FREQUENCY Full ew 5-10. Connect the OUTPUT of the Model 205AG to the input of an electronic counter. The counter should read a frequency of,; 20 Hz. 5-11. Turn the FREQUENCY dial to the full CCW posi tion. A frequency of 200 Hz should be read on the counter. 5-12. Repeat steps 5-10 and 5-11 except set FREQUENCY RANGE to XIO. The output of the Model 205AG should vary from a frequency ,; 200 Hz to a frequency 2 kHz. 5-13. Again repeat steps 5-10 and 5-11 except set FRE QUENCY RANGE to XlOO. The output of the Model 205AG should vary from a frequency ,; 2 kHz to a frequency 20 kHz. 5-14. DIAL ACCURACY. Specification 2% of dial setting If the instrument does not meet this specification refer to Paragraph 5-74. 5-15. Connect the OUTPUT of the Model 205AG to an electronic counter. -NOTE- Allow at least 5 minutes warmup period before performing the remainder of this check. 5-16. Set the Model 205AG controls as indicated in Paragraph 5-9 except set the FREQUENCY dial to 20. 5-17. C