Boonton 1121 Instruction Manual

Download

INSTRUCTION MANUAL

MODEL 1121

PROGRAMMABLE

AUDIO ANALYZER

BOONTON

ELECTRONICS CORPORATION

984034CMB

791 ROUTE 10, RANDOLPH, NJ 07869-1980

TELEPHONE: 201-584-1077 FAX: 201-584-3037

April 1993

SAFETY SUMMARY

The following general safety precautions must be observed during all phases of operation and maintenance of this instrument. Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of design. manufacture. and intended use of the instrument. Boonton

Electronics assumes no liability for the customer’s failure to comply with these requirements.

THE INSTRUMENT MUST BE GROUNDED

To minimize shock hazard the instrument chassis and cabinet must be connetted to an electrical ground. The instrument is equipped with a three conductor. three prong a.c. power cable. The power cable must either be plugged into an approved three-contact electrical outlet or used with a three-contact to a two-contact adapter with the (green) grounding wire firmly connected toan electrical ground at the power outlet.

DO NOT OPERATE THE INSTRUMENT IN AN EXPLOSIVE ATMOSPHERE.

Do not operate the instrument in the presence of flammable gases or fumes.

KEEP AWAY FROM LIVE CIRCUITS.

Operating personnel must not remove instrument covers. Component replacement and internal adjust-

ments must be made by quailfied maintenance personnel. Do not replace components with the power cable

connected. Under certain conditions dangerous voltages may exist even though the power cable was

removed. therefore: always disconnect power and discharge circuits before touching them.

DO NOT SERVICE OR ADJUST ALONE.

Do not attempt internal service or adjustment unless another person, capable of rendering first aid and

resuscitation, is present.

DO NOT SUBSTITUTE PARTS OR MODIFY INSTRUMENT.

Do not install substitute parts or perform any unauthorized modification of the insturment. Return the

instrument to Boonton Electronics for repair to ensure that the safety features are maintained.

SAFETY SYMBOLS.

This safety requirement symbol (located on the rear panel) has been adopted by the

International Electrotechnical Commission. Document 66 (Central Office) 3, Para-

graph 5.3. which directs that and instrument be so labeled if. for the correct use of the

instrument. it is necessary to reler to the instruction manual. In this case it is

[WARNlNC)

recommended that reference be made to the instruction manual when connecting the instrument to the proper power source. Verify that the correct fuse is installed for the power available. and that the switch on the rear panel is set to the applicable operating voltage.

The CAUTION sign denotes a hazard. It calls attention to an operation procedure. practice. or the like. which. if not correctly performed or adhered to. could result in damage to or destruction of part or all of the equipment. Do not proceed beyond a CAUTION sign until the indicated conditions are fully understood and met.

The WARNING sign denotesa hazard. It calls attention to an operation procedure.

practice. or the like. which, if not correctly performed or adhered to. could result in injury or loss of life. Do not proceed beyond a WARNING sign until the indicated

conditions are fully understood and met.

Indicates dangerous voltages.

Table of Contents

Paragraph

SECTION I - GENERAL INFORMATION

l-l. INTRODUCTION.

1-3. DESCRIPTION. l-5. ACCESSORIES. 1-7. OPTIONS. 1-9. SPECIFICATI’Ok.’ :

.........................................................................................................

.........................

SECTION II - INSTALJATION

2-1. INTRODUCTION.

2-3. UNPACKING. 2-5. MOUNTING. 2-7. POWERREQUIk~M&l+. : : 2-10. CABLE CONNECTIONS.

2-13. PRELIMINARY CHECK.

.........................................................................

SECTION III - OPERATION

.................................................................

Page

;-;

l-l 1-1

l-l

;-;

: 2-1

;:;

2-2

3-l. INTRODUCTION. 3-3. OPERATING CONkO~,hiX~~TbR’s AN;) &ti%IOk: :

3-5. OPERATING INSTRUCTIONS. 3-7. INITIALCONDITIONS. 3-9. LOCALOPERATION.

3-10. Function Selection. 3-11. Data Entry Operation. 3-13. Analyzer Measurement Description.

3-14. Analyzer Input Description. 3-15. Frequency Measurement Function. 3-16. Frequency Measurement Display Units. 3-17. Special Frequency Measurement Modes.

3-18. Level Measurement Function. 3-19. Level Measurement Display Units. 3-20. Special Level Measurement Modes. 3-21. Distortion Measurement Function.

3.22. Distortion Measurement Display Units. 3-23. Special Distortion Measurement Modes. 3-24. SINAD Measurement Function. 3-25. SINAD Measurement Display Units. 3-26. Special SINAD Measurement Modes.

3-27. S/N Measurement Function. 3-28. S/N Measurement Display Units. 3-29. Special S/N Measurement Modes.

...............................

..............................................................

......................

.....................

..........................................

....................

...................

....................

...................

....................

................................... .....................................................

..........

..................

........

3-l 3-l 3-1

3-1 3-1

z 3-6

3-6 3-6 3-6 z

3-6 3-7

3-9 z;

zz 3-9

3-9

Paragraph

Page

3-30. UsingtheRatioMode. 3-31. Ratio Measurement Display Units.

3-32.

Using Analyzer Filters.

........................

....................

........................

3-35. Audio Oscillator General Description. 3-36. Oscillator Output Description.

...

3-37. Source Frequency Display and Selection. 3-38. Source Frequency Lock Mode Description. 3-40. Source Level Display And Selection. 3-41. Amplitude Display Units.

.......................

3-42. Step Size and Step Key Operation.

3-43. Increment/Decrement Program Number. 3-44. Increment/Decrement Frequency Values. 3-45. Increment/Decrement Level Values. 3-46. Sweep Mode General Description. 3-47. SWEEP Key Description.

3-48. START Key Description.

3-49. STOP Key Description. 3-50. X AXIS Output Description. 3-51. Y AXIS Output Description.

353. PEN Output Description.

3-54. UsingTheSweepMode. 3-56. Generating Frequency Sweeps. 3-57. Generating Level Sweeps.

.......................

........................

......................

.......................

.....................

.......................

3-58. Program Store And Recall Description.

3-59. Store Operation. 3-60. Recall Operation. 3-61. Program Memory Initialization. 3-62. Special Function Description. 3-63. Option Switch Functions.

364. Mode Alteration functions.

..........................

.....................

......................

.......................

3-70. Calibration And Test Functions. 3-71. S/N Delay Functions.

.........................

3-72. Frequency Sweep Resolution Functions.

3-73. Sweep Rate Functions.

........................

3-74. AC Detector Selection Functions. 3-75. Source Impedance Selection Functions. 3-76. dBV/dBm Display Mode Functions. 3-77. Option Switch, A4S1, Operation.

3-79.

Error Codes.

.....................

: : : : : : : : : : : : : : : : : :

..................

.................

...................

....................

.................

..................

...................

....................

..................

....................

..................

....................

..................

...................

3-80. REMOTEOPEd4T;dN.’ : : : : : : : : : : : : : : : : : : : : : : : 3-82. SettingtheBusAddress. 3-83. Entering the Remote Mode.

3.84. ReturningtoLocalMode. 3-85. Triggered Operation.

3-86. Talk Operation.

..........................

3-87. Talk Status (TS) Mode.

388. Talk Value (TV) Mode. 3-89. Talk Program (TP) Mode.

3.90. TalkFunction(TF)Mode.

3-91.TalkL.eam(TL)Mode.

3-92.

Talk Burst (TB) Mode.

.......................

......................

.......................

.........................

........................

.......................

........................

3-93. End-Of-String (EOS) Control. ’ : : : : : 1 : : 1 : : : : : : : 1 : : : : 3-94. Using “Service Request” (SRQ).

3-95.

Bus Co mmand Responses.

.....................

.......................

. 3-9 . 3-9

3-10 . 3-10 . 3-11 . 3-11 . 3-11

. 3-11 . 3-11 .3l2 .

3-12 . 3-12 . 3-12

. 3-12 . 3-12 . 3-12 . 3-12

. 3-12 . 3-12 . 3-u . 3-13 . 3-13 . 3-13 . 3-13

. 3-13 .

3-13 . 3-13 . 3-14 . 3-14 . 3-14 . 3-14

. 3-14 . 3-14 . 3-18 . 318 . 3-18 . 3-18

. 318 . 3-18 . 3-18 . 3-18 . 3-18 . 3-18

. 3-18

. 321

. 3-21 . 321 . 3-21 . 3-21 . 3-21

. 3-21 . 3-21 . 3-21 . 3-21

Paragraph

3-96. Program Function Mnemonics. 3-97. Number Formatting. 3-98. DataString Format. 3-99. Data String Errors.

3-100. DataString Examples. 3-101. Store and Rexall Operation.

............................................... y;

....................................................

........................

SECI’ION IV - THEORY OF OPERATION

ZJ-

3-23

...................... 3-23

4-l. INTRODUCTION. 4-3.FUNCTIONALBLOCikkAM. 4-14. DETAILED CIRCUIT DESCRIPTIOk 4-15. All Power Supply Circuits. 4-20. A10 Motherboard Circuits. 4-23. A5cPuCiicuits.

4-31. Al2 Display And Al3 Keyboard Circuits. 4-35. A4 Frequency Counter Circuits. 4-44. AOInput Circuits. 4-51. Al Filter Circuits. 4-55. A2 Notch Filter Circuits. 4-68. A6Source Circuits.

4-76. A7 Output Circuits.

4-61. A3 Detector Circuits.

..........................

.......................... 4-9

..........................

.........................

......................

...................

.......................

..................... 4-7

........................ 4-9

SECTION V -

5-l. INTRODUCTION. 5-3. SAFETYREQUIREhiEiTi. : : : : : : 5-5. REQUIRED TEST EQUIPMENT. 5-7. CLEANING PROCEDURE. 5-9. REMOVAL AND REPLACEMENT. 5-10. Instrument covers. 5-11. Display/Keyboard Access. 5-12. Plug-in Circuit Boards.

5-13. OptionalFilters. 5-14. Firmware Integrated Circuit. 5-15. Component Removal. 5-16. INSPECTION. 5-18. PERFORMANCE TESTS.

5-20. Initial Calibration.

5-21. Analyzer DC Level Accuracy.

5-22. Analyzer AC Level Accuracy.

5.23. Analyzer Level Flatness. 5-25. Source Impedance Accuracy. 5-26. Source Level Accuracy. 5-28. Source Level Flatness. 5-31. Analyzer Low Level AC Accuracy. 5-32. Frequency Accuracy. 5-33. Source Frequency Accuracy. 5-34. Analyzer Frequency Accuracy. 5-35. Low-Pass Filter Accuracy.

..........................

.........................

...........................

......................... 5-4

............................

.......................... 5-4

........................

........................ 5-5

.........................

.............................................

.....................

.......................

....................

.......................

...................... 5-3

.......................

..................... 5-5

.....................

..................... 5-5

.......................

...................... 5-7

.......................

4-l

..................

.................. 4-6

4-l 4-2 4-2 4-5

4-5

4-8

4-13 4-14 4-11

MAINTENANCE

.................

5-l 5-l 5-l

5-1 5-l 5-l 5-l

5-l 5-3

5-4 5-4

5-5 5-5

5-6 z:

5-7 5-7

III

Paragraph

Page

S-37. Residual Distortion and Noise. 5-39. Residual Signal-to-Noise Ratio.

5-41. Common Mode Rejection Ratio.

542. Optional Filter Accuracy.

543. Optional Filter Test Connections. 5-44. 4OOHzHigh-PassFilterAccuracy.

545. AUDIO Band-Pass Filter Accuracy.

5-46. CCITTFilter Accuracy.

547. CCIR Filter Accuracy.

548. A,B,andCWeightingFilterAccuracy.

549. C-MESSAGE Filter Accuracy. 5-50. ADJUSThiENTS. 5-52. All Power Supply Adjustment. 5-54. AllR6 Power Fail Adjustment. 5-55. A5 CPU Adjustment.

5-57. A5Yl Tiiebase Frequency Adjustment. 5-58. A3 Notch Board Adjustments. 5-59. A3R57 Balance and A3R58 Tune Adjustments. 5-60. A0 Input Board Adjustments. 5-62. AOR29, AOR12, AOR and AOC35 CMRR Adjustments. 5-63. AK5 and AOC32 Flatness Adjustments.

564. AOClO and AOC33 Flatness Adjustments.

5-65. A7 Output Board Adjustments.

566. A7R21, A7R17, and A7Rl.5 Adjustments. 5-67. A6 Source Board Adjustments.

5-68. A6R23 Output Level Adjustment.

5-69. A37 CCIR, CCIR/ARM Filter Board Adjustment. 5-71. A37Rll CCIR Cal Adjustment. 5-72. TROUBLESHOOTING. 5-76. TROUBLELOCALIZATION: : : : : : : : : : : : : : : : : : : : : : .5-25 5-78. Special Diagnostic Function Codes. 5-79. DACTest Code. 5-82. Counter Plug-in Board Test. ’ : : : 1 : : : : : : : : : : : : : : : : : : : 5-26

5.83. Input And Filter Plug-in Board Test.

5.84. Notch And Detector Plug-in Board Test.

.........................

.....

..........................

......................

.......................

.....................

....................

........................

...................

: : : : : : : : : : : : : : : : : : : : : : 5-22

......................

...................

......................

.................

.......................

..............

...................

..................

......................

...................

.......................

......................

................

......................

....................

..................

5-7 5-7 5-7

.5-8

5-8 5-8

5-8

.5-8

5-8 5-8 5-9

5-22 5-22 5-23 5-23 5-23 5-23

5-23 5-23

5-24 5-24

5-24 5-24 5-24 5-25 5-25 5-25

. 5-25

5-25 5-25

5-26 5-26

SECTION VI - PARTS LIST

6-l. INTRODUCIION. . . . . . . . . . . . . . . . . . . . . . . . . . . .6-l

SECTION VII - SCHEMATIC DIAGRAMS

List of Tables

Table

TABLE l-l. PERFORMANCE SPECIFICATIONS. TABLE l-l. PERFORMANCE SPECIFICATIONS CObiINiJED: : TABLE l-l. PERFORMANCE SPECIFICATIONS CONTINUED. TABLE 2-l. INITIAL CONDITIONS. TABLE 3-l. CONTROLS, INDICATORS AND dOiJN&‘ORS. TABLE 3-2. FUNCTION DISPLAY AND DATA ENTRY UNITS. TABLE 3-3. VALID FUNCTION ARGUMENT RANGE. TABLE3-4.INPUTLEVELRANGE.S. TABLE 3-5. DISTORTION AND SINAD RANGES. TABLE3-6.OUTPUTLEVELRANGES. TABLE 3-7. SPECIAL FUNCTIONS.

TABLE 3-8. OPTION SWITCH A4Sl. TABLE 3-9. ERROR CODES. TABLE 3-10. IEEE488 BUS MNEMONICS. TABLE 3-11. TALK FUNCTION (TF) DECODING. TABLE 3-12. BUS COMMAND RESPONSES. TABLE 5-1. RECOMMENDED TEST EQUIPMBNT.’ TABLE 5-2. OPTIONAL FILTERS. TABLE 5-3. ANALYZER DC LEVEL ACCURACY TEST RECORD. TABLE 5-4. ANALYZER AC LEVEL ACCURACY TEST RECORD.

TABLE 5-5. ANALYZER AC LEVEL FLATNESS TEST RECORD. TABLE 5-6. SOURCE IMPEDANCE ACCURACY TEST RECORD. TABLE 5-7. SOURCE LEVEL ACCURACY TEST RECORD. TABLE 5-8. SOURCE LEVEL FLATNESS TEST RECORD. TABLE 5-9. ANALYZER LOW LEVEL AC ACCURACY TEST RECORD.

TABLE 5-10. SOURCE FREQUENCY ACCURACY TEST RECORD. TABLE5-11. ANALYZER FREQUENCY ACCURACY TESTRECORD: : : TABLE 5-12. FILTER ACCURACY TEST RECORD. TABLE 5-13. RESIDUAL DISTORTION TEST RECORD. : : : TABLE 5-14. RESIDUAL SIGNAL-TO-NOISE TEST RECORD. TABLE5-15. COMMON MODE REJECTION RATIO TEST RECORD. : : : : : : . . TABLE 5-16. CCITT FILTER ACCURACY TEST RECORD.

TABLE 5-17. CCIR FILTER ACCURACY TEST RECORD. TABLE 5-18. A WEIGHTING FILTER ACCURACY TEST RECORD. TABLE 5-19. B WEIGHTING FILTER ACCURACY TEST RECORD.

TABLE 5-20, C WEIGHTING FILTER ACCURACY TEST RECORD. ......... 5-20

TABLE 5-21. C-MESSAGE FILTER ACCURACY TEST RECORD.

TABLE 5-22. LIST OF ADJUSTMENTS.

TABLE5-23. DIAGNOSTICERROR CODEdE&kIiTiON. .

TABLE 6-l. MANUFACTURER’S FEDERAL SUPPLY CODE NUMBERS. TABLE 6-2. REPLACEABLE PARTS LIST. TABLE 7-l. LIST OF SCHEMATICS.

........................

.....................

....................

......................

.....................

...................

......................

...................

.....................

.............. 3-S

................

...............

.............

......... l-2

..........

...........

........

. : : :

........... 3-7

............

........... 5-14

...........

: : : : :

........ 3-3

.......... 5-9

..........

.......

...... 5-13

......

...

.........

..........

....... 5-22

....... 5-26

.......

Page

1-3 1-4 2-2

3-10

3-11 3-14 3-15 3-16 3-17 3-19 3-20 3-22

5-2 5-3

5-10 5-11

5-12 5-12 5-12 5-13

5-U

5-14 5-15

. 5-15

5-16

5-17 5-18 5-19

5-21

6-l 6-2

7-l

Figure 7-37. CCIR Board AlA32,A33 Schematic. ..................

Figure7-38.~B,CWTNGBoardA1A34~S~PartsLoc.Di ag.

.............

Figure 7-39. &B,C WTNG Board AlA34,35,36 Schematic. ...............

Figure7-4O.AUDIOBoardAlA37PartsLocationDiapm. ..............

Fqpre 741. AUDIO Board AL437 Schematic. ...................

F.i.ie7-42C-MESSAGEBoardAlA38PartsLocationDiag. .............

Figure 7-43. C-MESSAGE Board AlA Schematic. .................

7-39 7-40 7-40

7-41

7-41 7-42 7-42

MODEL 1121 AUDIO ANALYZER

General Information

section 1

SECTION I

GENERAL INFORMATION

l-l.

INTRODUCTION.

1-2. This instruction manual

provides installation, operating and maintenance instructions, theory of operation, schematics and parts lists for the Model 1121 Audio

Wr-

13. DESCRIPTION.

l-4. The Model ll21 is a versatile, precision, solid-state instrument with features and performance characteristics especially suited to laboratory and industrial applications. Human engineering considerations have been emphasized in both the mechanical and electrical design of the Model 1121.

The result is an audio analyzer that is easy and convenient to

use. Among the outstanding features are:

Versatile Audio Analyzer.

Advanced generation and measurement techniques enable the Model 1121 to provide fast, accurate measurements. Measurement modes include frequency, AC or DC level, distortion, SINAD, signal-to-noise and full ratiometric capability. The precision audio source provides accurate, low distortion signals over wide frequency and level ranges. Demanding applications are satisfied by the high output power capability and selectable output impedance.

Ultra-low Distortion

. The mark of quality for any audio analyzer is low residual distortion and noise. The total harmonic distortion of the Model 1121 is specified as less than 0.01% with typical performance an order of magnitude better than specified.

Versatile

Source

Output.

The Model 1121 fea-

tures wide control over its output configurations. Source

impedance can be set to SO, 150, or 600 ohms in either a floating or single-ended co&guration. All source impedan-

ces are available at the same set of output connectors,

eliminating the need to multiplex separate SO ohm and high impedance outputs.

Balanced Input.

The Model 1121 has a fully dif-

ferential/balanced input for testing bridged amplifiers and

power supplies.

IEEE-488 bus status is also presented.

Full Range

Filter Selections.

The Model

1121 provides a wide range of filter selections and weighting

characteristics for industry-standard audio measurements.

Sweep

Operation.

Frequency or level can be swept in user-sehed linear or logarithmic steps over any portion of the range. The selected analyzer measurement provides the Y axis information. Rear panel X axis, Y axis and PEN outputs are provided for plotter application.

Instrument Setup Memory.

Up to 99 front panel setups containing all data required to configure the instrument to a previous operating mode can be stored in non-

volatile memory for future recall. The last valid instrument

setup before power interruption is also saved automatically and restored when power is resumed.

IEEE-488 lnterfa~e

BUS.

All instrument functions are programmable except line on/off. Annunciators to the left of the BUS/PRGM display window show the status of bus activity. The 1121 is designed to interface easily with controllers currently in use. A versatile free-form number entry system is used so that the 1121 will accept any conceivable valid number string. Triggering may be performed in immediate or wait modes. There are six talk modes which can be addressed in either the remote or local state. The 1121 also provides a choice of several end-of-string terminators. Service-request (SRQ) can be asserted on errors or using the front panel SRQ key and the LCL4INK key will force return

to local control when using the bus as long as a lockout

message has not been sent.

l-5.

ACCESSORIES.

1-6. The available accessories are listed in Table l-l. The AC power cord, spare input, output and line fuses are supplied

with the instrument:

1-7.

OPTIONS.

18. The available options are listed in Table 1-1.

Separate Displays of All Functions.

The Model 1121 has 3 separate display windows to simultaneously present analyzer measurements, source settings and program number or bus address information. Continuous display of

1-9.

SPECIFICATIONS.

l-10. Performance specilications for the Model 1121 Audio Analyzer are listed in Table l-l.

l-l

section 1

TABLE l-l. PERFORMANCE SPECIFICATIONS.

SYSTEM SPECIFICATIONS

General Information

SigMl-tddW

Fundamental Frequency Range:

10 Hz to 100 kHz usable to 140 kHz

Display Range 0.00

to 140.00 dB

Afcurrrcy: +,ldB

LnputVoUageRangez Residual Noise (the greater of):

5OmVto3OOV

85dBorlO/tV,8OkHzBW 85dBor#)~V;22OkHzBW

85dBor4O/tV;5OOkHzBW

SOURCE SPECIFICATIONS

Frequency

Ranges lOHzto14OkHz Resolution:

0.001 Hz; 10.000 to 199.999 Hz

0.01 Hz; 200.00 to 1999.99 Hz

0.1 Hz; 2.oooO to 19.9999 kHz

1.0 Hz; 2O.ooO to 140.000 kHz

Accuracy: 10 ppk~ + timebase accuracy + 1 count

Level

FE&M& 16.000 V rms, open circuit

16.CNM V, 3.000 t, 300.0 mV, 30.00 mV

Re!sdution:

0.01 mV, 0.00 to 30.00 mV

0.1 mV, 30.0 to 300.0 mV lmV,3OOto3000mV

mV, 3.ooO to 16.000 V

Accuracy (settiqp fiwm Oh0 mV to 16.000 V):

2 05 % of setting + 0.05 % of range;

10Hzto5OkHz

2 1.0 % of setting + 0.05 % of range;

5OkHzto1OOkHz

2 1.5 % of setting + 0.1% of range;

1OOkHzto14OkHz

Distottion

Residual Distortion and Noise (the greater of):

-80dBor10~V,10Hzto20)8080zBW

-74dBorm~V;lOHzto50IrHz,~LHz’BW

-7OdBor4O~V,1OHzto5OkHq5OOkHzBW

-65dBor4O~V,5Oto1OOkHz,5OOkHzBW

Flatness, ref 1 kH2

(030 mV to 8 V into 50 ohms):

+ 0.5 %; 10 Hz to 50 kHz 2 1.0 %; 10 Hz to 100 kHz f 1.5 %; 10 Hz to 140 kHz

output

Impedance:

5oohms+2%

lxlohms&l%

6OOohmsZkl%

Distortion and Noise (the greater of):

0.01% (-80 dB) or 10 p V, 10 Hz to 20 kHz, 80 kHz bandwidth

0.02 % (-74

dB) or 20 p V,

10 Hz to 50 kHz, 220 kHz bandwidth

0.032 % (-70

dB) or 35 V,

10 Hz to 50 kHz, 500 kHz bandwidth

0.056 % (-65 dB) or 35 /.f v;

50 to 100 kHz, 500 kHz bandwidth

0.1% (-60 dB) or 35pV; 100 to 140 kHz, 500 kHz bandwidth

Output Power (50 ohm source):

31.07 dBm (8.00 V) into Xl ohm load

29.82

dBm (12.00 V) into 150 ohm load

25.60 dBm (14.76 V) into 600 ohm load

ANALYZER SPECIFICATIONS

Frequency Meesurement

Rangez 5Hzto2OOkHz

Sensitivityz

5 mV in the Frequency mode 0.01 Hz; 200.00 to 1999.99 Hz 50 mV in the Distortion and SINAD modes 0.1 Hz; 2.0000 to 19.9999 kHz

Accuracy Timebase accuracy + 1 count 1.0 Hz; 20.000 to 199.999 kHz

l-2

_.- ..__ “-.- ._-. ^^

Resolution: (for input levels below 100 mV the

resolution is reduced by a factor of 10)

0.001 Hz; 5.ooO to 199.999 Hz

General Information

TABLE l-l. PERPORMANCE SPECIFICATIONS CONTINUED.

Timebase

Type 10 MHz TCXO

-racy: +lPP*

nc Level Meas4Jrement

Range: (hllscah?)

300.0 v, 30.00 v, 3.ooo v, W.OmV, 3O.OOmV, 3.tMOmV, 0.3OOOmV

Overrange: 33 % except on 300 V range

Accuracy:

~1%;5OHzto5OLHz,1mVto3OOV +2%;ZlHzto100IrHz,1mVto3tXIV ~3%;10Hztol00IrHz,1mVto300V ~4%;lOHztolOOkHq0.3mVto30OV

Flatness: (1

-c05%;5oHzto5okHz ~1.0%;2OHzto1oOkHz ~2.0%;10Hzto1OokHz

DC Level

Rauge: (full sea?) 300.0 v, 30.00 v, 3.ooo v Ovemmgc 33 % except on 300 V range

Aceurucy~ ‘c 1% or 6 mV whichever is greater

mV to 300 V)

Measurement

Common Mode Rejection Ratio

CMRRz

> 70dB;ZlHztolkHz > 45dB;lKHzto#)kHz

Limits:

4.25 V pk; 3.ooO V range

42.5 V pk; 30.00 V range 425 V pk; 300.0 V range

Analyzer Input

Type: Balanced (full differential)

IIUjltdUWE:

100 k ohms f 1 %, -Z 300 pF, each side to ground

Prote4ztion:

Excessive common mode levels are hardware limited on all input ranges and fuse protection is employed against peak levels exceeding 425 volts

Distortion Measurement

Fundamental Frequency Range:

10 Hz to 100 kHz usable to 140 kHz

Resolution:

O.ooOOl %; < 0.11ooo %

0.0001 %; < l.looo %

0.001 I; < 11.000 %

0.01%; < 100.00 %

ww Rnnee:

O.t.NMOl to loO.aO % (-140.00 to 0.00 dB)

*ldB;#)Hzto2OkHz

~2dB;10Hzto1oOkHz

InputVol@e~

5OmVto3OOV

Distortiou Meas-nt Rangez

0.01% (-So dB) or 1opv; loHzto2OkHqSOkHzbandwidth

0.02 % (-74 d.B) or 20 p v; loHzto5OkHz,22OkHzbandwidth

0.032 % (-70 dB) or 40 p v; loHzto5OkHz,5OOkHzbandwidth

O.O56%(-65dB)or4OCtV; 50 to 100 kHz, 500 kHz bandwidth

SINAD Meastuemunt

Fundamental

lOHztoltDkHzusableto14OkHz (tuned to source frequency setting)

Display Range: 0.00

A-racy.

+_ldB;#)Hzto2OkHz +2dB;10Hzto1oOkHz

Input Volw Range: SO

Frequency Range:

to 140.00 dB

mV to 300 V

SINAD Measurement Range:

8OdBor lOpV,

10 Hz to 20 IrHz, SO kHz bandwidth

74dBor#)pV,

lo Hz to 50 kHz, 220 kHz bandwidth

7OdBor4O/rV,

10 Hz to 50 kHz, 500 kHz bandwidth 65dBor4O,uV, 50 to 100 kHz, 500 kHz bandwidth

Standard

Audio Filteru

30 kHz Low-pass Filter

Accuracy: 3OkHz+-2kHz Roll& Third-order Butterworth, 60 dB/decade

80 kHz Low-pass Filter Accurclcy. SOkHz*4kHz

RoUoffi

Third-order Butterworth, 60 dB/decade

220 kliz Law-pass Filter Accurslcy: 22okHZk2okHz

Rolloff: Third-order Butterworth, 60 dB/decade

--__I ____.-. I--

l-3

Section 1

TABLE l-l. PERFORMANCE SPECIFICATIONS CONTINUED.

Optionel Audio Filters

400 Hz High-pass Filter

Accuracy: 4cmHz*4oHz Rolloff:

Audio Band-pass Fitter

ACCUracy:

Seventh-order Butterworth, 140 dB/decade

22.4 Hz + 5 %, 60 dB/decade roiloff

22.4 kHz 2 5 %, 60 dB/octave rolloff

A, I$ C Weighting Filter

ACCUracy:

2 0.2 dB; 1.0 kHz

+, 1.0 dB; 40 Hz to 5.0 kHz

+1.5dB;25to4OHz,5.0to10.0kHz

+ 2.0 dB; 20 to 25 Hz# 10.0 to 20.0 kHz

SUPPLEMENTAL INFORMATION

General Information

CClTI’ or C-MESSAGE Rand-pass Ftlter A--s

~02dB;800HzcclTr, f 0.2 cii3; loo0 Hz C-MESSAGE

-+1.0dB;3OOto3OOOHz +2.odB;5OtoxlOHz,3.0to35kHz

~3.0d.B;35toSkHz

CCIR ur CCIWARM

Accuracy:

Rand-pass Fitter

+- 0.2 cm; 63 to 7.1 kHz 2 0.4 CiB; 7.1 to 10 kHz ~05dB,200t06300Hz ~1.0dB;31.5to2OOHz,10to2OkHz

+2.0dB-~;2Oto31.5kHz

AC Meesurement

Ramhvidtb: 5 Hz

to 500 kHz

RMS Detectoc

True rms responding for signals with a crest factor of < 3

Average

Detectors

Average responding rms calibrated

Quasi-peak Detectoc

Meets

CCIR recommendation 468-3

Accuracy: +6%;2OHztoU)kHz

Analyzer Measurement Speed

Function:

Frequency Level

Fir&Reading: Rate:

<lscc 4 rdn&sec

<lseC 10 rdngs/sec Distortion <lsec 8rdngs/sec SINAD

<lsec

S/N <2sec

8 rdngs/sec

1 rdn&ec

Frequency Measurement

Technique:

Reciprocal measurement with 10 MHz timebase

Physical ad Environmental Specificetlons

GeOed:

Manufactured to the intent of MILT2&3WE, Type III, Class 5, Style E

Power Requirements:

100,120,220,240 volts AC, + 10 %, 50 to 400 Hz,

80VA

Operatiug Temperature: 0 Operating Humidity < 952 5 %

Warm-up Time: 30 minutes

Dimenshs:

to 55 degrees centigrade

non-condensing

17.75 inches (45.1 cm) wide, 5.85 inches (14.9 cm)

high, 18 inches (45.8 cm) deep

Weight: 25 lbs (113 kg)

Accessories Included:

Spare input, output and line fuses and AC power cord

Accessories Available:

95OW4 Rack mounting hardware 950043 Chassis slide kit

954018 Single binding post to BNC (M) 954019 BNC (F) to phono plug 954020 Phono jack to BNC (M) 954021 Two conductor shielded balanced line, 36 ” 954022 XLR Audio conncctor to three banana

P’ W

options:

-01 Rear panel input and output

-11 400 Hz high-pass filter

-12 CClTl’ band-pass filter

-l3 CCIR band-pass filter

-15 A weighting filter

-16 B weighting filter

-17 C weighting filter

-18 Audio band-pass filter

-19 C-Message band-pass filter

Remote Interlace:

IEEE--1978. Implements AHl, SHl, T6, TEO, LA, LEO, SRl, RLl, PPO, DCl, DTl, CO, and El

l-4

- -..---__

“--

General Information

---------.-

17.34 -

‘

l&SO 10.00

Figure l-l. Outline Dimensions.

l-5

c’

section 1

General Information

1-6

Installation

Section 2

SECTION II

INSTALLATION

2-1.

INTRODUCTION.

2-2. This sqction umtains the unpackiq mount& power

requirements, cable connections, and preliminary check-out instructions for the Model 1121 Audio Analyzer.

2-3. UNPACKING.

24. The instrument is shipped complete and is ready to use upon receipt. Unpack the instrument from its shipping container and inspect for damage that may have occurred during shipment. Refer to Figure 2-l.

NOTE

Save rhe packing mate&al and conkainer for possible

use in teshipmenr of the instrumenl.

2-5. MOUNTING.

24. For bench mounting choose a clean, sturdy, uncluttered mounting surface. For rack mounting, an accessory kit is available which provides mounting ears. The rack mounting kit contains the required hardware and instructions.

2-7. POWER REQUIREMENTS. 2%. The instrument has a tapped power transformer and two

line voltage selection switches which permit operation from

100,120,220, or 240 volt + - 10 %, 50 to 400 Hz, single phase

AC power sources.

CAUTION

Always make certain that the line voltage selection

swikhes rue set to rhe correcl positions coresponding

to the voltage of

rhe conzct tadng is installed befoe connecting the

instmmenf to any AC power source.

2-9. Set the rear panel line voltage selector switches to the appropriate positions as indicated in the Line Voltage Select

the

ACpower source, and that a fuse

Line

Voltage

Select Chart

Chart and check that the line fuse is correct for the selected power source.

2-10.

CABLE CONNECTIONS.

2-11. Front panel connector:

INPUT.

conne&ors and chassis ground allow connection of external audio signals for analysis. The input impedance is 100 k ohms either side to ground. The LOW terminal is connected to chassis ground in the non-floating mode.

OUTPUT. Source output HIGH and LOW BNC type

connectors and chassis ground allow connection to external

devices and components. The output impedance is selected using special functions 75,76, and 77. The LOW terminal is connected to chassis ground in the non-floating mode.

2-E Rear panel connectors:

MONITOR.

tor provides a scaled output of the input signal in the level,

frequency and signal-to-noise measurement modes and a scaled output of the input signal with the fundamental removed in the distortion and SINAD measurement modes. The output impedance is 600 ohms.

X a means of connecting to an external 10 MHz counter reference. The external reference is automatically selected when a ?TL level signal is present.

SYNC. The SYNC BNC type output connector provides a lTL compatible signal relative to the source frequency setting.

XAXIS.The X AXIS BNC type output connector

provides a0 to 5 volt d. c. level relative to the sweep frequency or level in the sweep mode. The output impedance is loo0

Ohms.

Y AXIS. The Y AXIS BNC type output connector

provides a 0 to 5 volt d. c. level relative to the analyzer

measurement and entered HIGH and LOW plot limits. The output impedance is loo0 ohms.

Analyzer Input HIGH and LOW BNC type

The MONITOR BNC type output connec-

CLK.

The X CLK BNC type input connector provides

PEN.

The PEN BNC type output connector provides a

‘ITL compatible signal to control the pen of an external

2-l

Section 2

InstaJ.Jation

recorder.

2-13. PRELMNARY CHECK.

2-14. The preJhinary check verifies that the Model 1121 is operational and should be performed before the instrument

Section 2

KYJ3D legend illuminated. The ANALYZER display wiiJ contain the D message for one level measurement cycle. The initiaJize sequence resets aJJ functions and operating modes of the Model 1121 to the initia.Jized values and conditions listed in Table 2-1.

InstaJJation

Operation

SECTION III

OPERATION

3-1. INTRoDUCTloN.

33. This section contains the operating instructions for the Model 1121 Audio Analyzer.

3-3. OPERAnNG CONTFlOLS, INDICATORS AND CONNECTIONS.

3-4. The controls, indiators and eonneetors used during the operation of the instrument are listed in Table 3-l and shown in Fies 3-l and 3-2.

3-S. OPERATlNG INSTRUCTlONS.

34. The operating instructions for the Model 1121 are divided into sections of Initial Conditions, Local Operation and Remote Operation.

3.7. INlTlAL CONDITIONS. 3-8. Initialize the instrument as follows:

a. Connect the power cord to the instrument and to the desired power source. Refer to paragraph 2-7 for proper power application.

b. Set the front panel power switch to ON.

Depress the LCIANIT key.

d. The SOURCE display will contain the instrument firmware identification number and the other displays will contain dashes for a period of about two seconds. The SOURCE display will then contain 1OCNI.00 Hz with the KYBD legend ill~ted and the ANALYZER display will

change to contain the 0 message for one level measurement cycle.

33. LOCAL OPERATION. 3-10. Function Selection. The DATA ENTRY keypad is

common to all functions of the Model 1121. The KYBD legend determines the active display window to which the DATA ENTRY keypad is dedicated at any given time. To select a functioa simply depress the fun&ion key desired. The results will be the LED of the function key will be illuminated, the current value of the selected function will be displayed in the window above the key, and the KYBD legend will be

illuminated in the display window. The DATA ENTRY keypad is dedicated to the selected Bmetion and any unit

selection or number entq wig appear in the active display

window. When selecting measurement functions the [

message may appear to indicate that a measurement cannot

be displayed instantly for any of five possible reasons:

The first measurement cycle is in progress and can-

notke displayed

2. The measurements’ are not met, for example, frequency measurements cannot be made if the input level is too low.

3. The input level is over-range. The input signal is changing faster than the analyzer

can respond.

5, The notch filter is in the process of beii tuned to

the fundament frequency in the distortion or SfNAD modes. 3-11. Datr Entry Operation. Once a function has been

selected, new values maybe entered with the DATA ENTRY keypad. To enter data simply depress the desired digit keys followed by the appropriate unit key or ENTER key. During digit selection a (‘) mark will appear in the display to the left

of the first digit selected to indicate the number in the display is in the process of being entered. No action is taken until the unit or ENTER key is depressed. The unit keys can also be used aside from number entry to select display modes. For example, to change the level measurement displayed in mV to logarithmic units in dBV, simply select the analyzer LEVEL key and depress the dB key in the DATA ENTRY keypad. The display program will calculate and display the logarithmic value. The ENTER key serves a dual function as

a dimensionless unit key for SPCL, ADRS, and PRGM num-

ber entry and also as a default unit terminator of V, %, and

Hz for functions where more than one unit can be selected.

342.

Many

of the Model 1121 functions have multiple display and entry modes. Listed in table 3-2, Function Display And Data Entry Units, are the display legends which can be active for each function along with the unit keys in the DATA ENTRY keypad which select the available display modes. Argument entry ranges for all the Model 1121 functions are described in Table 3-3, Valid Function Argument Range. Number entry out of range of the sehxted functions wig result in an error displayed in the SOURCE display window. Errors

minimum signal requirements

3-1

Section 3 Operation

. . . ..I‘.

Figure 3-1. Model 1121, Front View.

3-2

Figure 3-2. Model 1121, Rear View.

_” .._ ..-. --l-lll_

Operation

section 3

TARIB X-1.

-_--- -. ---.--___ -,-.---.-- -~~-

or Connector

ANALYZER display

SOURCE d&p&y

BUS’PRGM display

ANALYZER keys

C0NTROL.S. lNDICATORS AND

Control,

Indicator,

FREQW

-IJLey DIST key

Figure

and Index

No.

CONNECl-ORS.

Function

Displays frequency, AC and DC level, distortion, SINAD, S/N and ratio measurements. (6 digit LED display)

Displays source frequency and level, frequency and level step sizes, special function, start, stop, low and high sweep values. Alternately displays error codes and messages. (8 digit LED display)

Displays current program number or IEEE-488 bus address. (2 digit LED display)

Selects the following active analyzer functions. Displayed in Hz or kHz with GATE indication. Displayed in V, mV, dBV or dBm. Displayed in %, dB, dFJV, dBm, V, or mV. Notch tune frequency dis-

played in Hz or kHz. Notch capable of automatic or manual tuuing.

SINAD key Displayed in dB. Notch filter is tuned to the source frequency setting.

Displayed in dB. Measured by monitoring the AC level while turning the source level on and off.

RATIO key

FILTER keys

FLOAT keys DATA ENTRY keyPad

SOURCE keys

F=Q

FREQ STEP key

LEVEL key LEVEL STEP key

Displays amplitude ratios in % or dB and frequency ratios in Hz or lrHz Selects optional filters, 30 kHz, 80 m 220 kHz low-pass or DC level

fdters. Selects floating or single-ended input and output connection. Used with the function keys to enter data into the active display desig-

nated by the KYBD annunciator. Selects the following active functions. Allows display and entry of the source frequency in Hz or kHz units.

Allows display and entry of the frequency increment value in Hz or Wz units for use with the step keys and the linear frequency sweep mode.

Allows display and entry of the source level in mV, V, dBV or Allows display and entry of the level increment value in mV, V, or dEi

units for use with the step keys and the linear and log level sweep mode.

dBm units.

3-3

section 3

TABLE 31. CONTROLS, INDICATORS AND CONNECTORS CONTINUED.

Control, Figure

Indicator,

and Indelc

Function

or Connector No.

Allows alteration to the normal analyzer modes of operation such as: range hold, notch tune hold, slow responding detector, and special modes for test& troubIeshoot& and automatic calibration.

Operation

SWEEP keyis

SWEEP key START key

STOP key

HIGH key

LINEswitcb

PROGRAM keys

PRGM key

3-1,9

3-1,lO

3-1,ll

3-1,12

Selects the following sweep parameters. Enables the start of the sweep Allows display and entry in Hz or kHz units of the starting sweep

frequency or in mV, V, dBV or dJ3m units of the start& sweep level. Allows display and entry in Hz or kHz units of the ending sweep

frequency or in mV, V, dBV or dBm units of the ending sweep 1eveL Allows display and entry of the upper Y axis scale value in units

compatible with the active analyzer measurement mode.

Allows display and entry of the lower Y axis scale value in units compatible with the active analyzer measurement mode.

Step keys increment or decrement the active source or sweep function in frequency or level step sizes and single steps the program location

fiUlCtiOU

Switches the instrument AC power on or off.

Selects the following program functions.

Mows display and entry of the store/recall program location.

sequence

and indicates sweep in progress.

Bus status

ADRS key

LCUINIT key

SRQ

STOW RCL key

key

3-1,x3

3-1,14 3-1,15

3-1,16

Stores the instrument setup at the current program location. RecaUs the instrument setup at the current program location. Displays the current IEEE-488 bus status; REM (remote enabled),

LSN (listener addressed), TLK (talker active), and SRQ (service request).

Allows display and entry of IEEE-488 bus address. Causes the instrument to “go-to-local” when remote enabled otherwise

executes the initialize sequence. Sets the IEEE-488 bus SRQ line true.

operation

TABLE 31. CONTROLS, INDICATORS AND CONNECTORS CONTINUED.

sectioll3

Control,

Indicator,

or Connector

0uTPuTcon~

INPuTcon-

optluMlconnedors

Ground connector 3-2,2 MONITORconnecW 3-2,3

SYNC connectur

XCLKconncctor

Figure

md Index

No.

3-1,17

34.18

3-2.1

33,4 3-2,s

Function

LOW and LOW terminal is

LOW and HIGH. The LOW terminal is mode.

Used to replace the front panel input and output Chassis ground connector, Provides a scaled output of the input signal in the frequency, level and

S/N modes. Provides a scaled output of the input sigual with the fun-

damental removed in the distortion and SINAD modes. Provides a ‘lTL compatible output relative to the source frequency. Provides a lTL compatible input for an external 10 MHz timebase

reference. Automatic switching to external reference when present.

HIGH.

Used to umnect the source to mental devices. The

co~etcted

Used to apply an external audio signal for analysis.

co~eckd

to chassis

ground in the non-floating

to chassis ground in the non-floating

co~edors.

mode.

x~COMWt4W

YAxIscoMectur

PEN connecW

IEEE-488 connector 33,9

Fuse holder 3-2,10

I VoMJIge sele!ctorswitches

AC coo~ector 3-2,12

3.2,6 3-2,7 3-2,s

3-2,11

Provides a 0 to 5 v DC output for plotter application.

Provides a 0 to 5 v DC output for plotter application. Provides a TIZ compatible output for plotter pen control. Provides a means for

cable. AC line fuse holder. Selects the desired line operating voltage.

AC power connector.

connecting the

standard IEEE-488 bus interface

3-5

Operation

can be cleared by depressing any key. If at any time prior to entry a wrong digit is entered, depress the CLR key to clear and restore the previous display.

3-W.

Analyzer Measurement Descriptioa The

1121 contains an independent distortion analyzer which can measure frequency, AC and DC level, distortion, SINAD and signal-to-noise. In addition, ratio measurements can be made

with all analyzer measurement modes A wide range of spe-

clal functlorGenha& the basic measurement modes without sacrificing the simpiiiled operation of the analyzer. Standard

and optional audio filters are provided to aid in harmonic distortion analysis and weighted noise measurements. Finally, the ability to store and recall specific measurement combinations aid in configmmg measurement applications for manual and remote use.

3-14. Analyzer input Description.

tion of the Model 1121 can be selected for single-ended or balanced/different operation. The input mode can be enabled using the front panel FLQAT key or over the IEEE483 bus interface.

3-15. Frequency Measurement Function.

1121 measures wide ranges of audio frequency with high accuracy and resolution. Microprocessor control of the reciprocal counter results in automatic selection of frequency

ranges for maximum resolution. Measurements are refer-

enced to an internal 10 MHz timebase accurate to 0.0001% and external reference capability is also provided.

3-16.

Frequency Measurement Display Units.

Frequency measurements can be displayed in Hz or kHz for values above 199.999 Hz with automatic selection of Hz units below this limit. To select the Frequency measurement function simply depress the FREQ key which illuminates both the key’s LED and the KYBD legend in the ANALYZER display. Display units can then be selected by depressing the Hz or kHz keys.

The input cxmligura-

The Model

Model

paragraph 3-74. A period sampling measurement technique

is employed which results ln adaptive measurement rates optimized to the period of the dominant AC component of

the input @al. This technique yields fast settled measurements in the AC level mode while effectively filtering large AC components in the DC level mode. Measurement bandwidth is selectable using the standard and optional filters to reject out-of-band noise or provide industry-standard weighting characteristics.

3-19. Level Measurement Dirpiay Units.

level measurements can be displayed in linear or logarithmic units. Linear measurements are displayed in mV or V with V automatically selected for levels above 750 mV and mV automatically selected for levels below 0.300 V. Logarithmic measurements are displayed in various forms. The default mode uses dBV units (dR relative to l.ooO V rms). Power in dBm units (dB relative to 1 mW) can be selected for various

impedances as described in paragraph 3-74. To select the

Level measurement function simply depress the LEVEL key which illuminates both the key’s LED and the KYBD legend in the ANALYZER display. The various display modes can then be selected by depressing the appropriate units associated with the desired display mode. For example, to select AC level in logarithmic units depress the dB key and to return the display to linear units depress the mV or V keys.

3-20.

Special Level Measurement Modes.

function 11 is provided to preset and hold specific level ranges to achieve faster first measurement rates and to eliminate possible range-to-range nonlinearity. Refer to paragraph 3-65. Special function 17 extends the measurements sampling period to provide a more consistent reading in the presence of noise. AC and DC calibration is performed through the use of special function codes 2tI through

24. The rms, average or quasi-peak AC detector type can be selected using special function 70, 71 or R respectively.

,Speciai functions 80 through 86 select logarlthmlc display

modes in dBV or dBm units.

AC and DC

Special

3-17. Special Frequency Measurement Modes.

Special function 11 is provided to preset and hold specific level ranges for frequency measurement. Refer to paragraph

3-65. The frequency measurement mode can function to

input levels 14 db below the selected level range. For example

by setting the 3,ooO volt level range, measurements can be

made with signal levels as low as 600 mV.

3-18. Level Measurement Function.

measures both AC and DC voltage with high dynamic range and selectable AC bandwidth. Resolution at full scale is 3000 counts with an additional 33 % overrange capability. The AC rms detector is true rms responding for signals with crest factors less than 3. Average and quasi-peak responding detectors (rms calibrated) can also be selected. Refer to

The Model 1121

3-6

3-21. Distortion Measurement Function. The Model

1121 measures total harmonic distortion and noise over a

wide range of frequency. The notch filter is automatically tuned to reject the fundamental frequency and pass only the harmonic and noise content..The AC measurement technlques are similar to those used iu the level measurement function yielding fast settled measurements. Measurement bandwidth is selectable to reject noise while accurately preserving harmonic components. Measurement results can be displayed in several forms. The combination of harmonics and noise can be displayed as an absolute level in mV, V, dBV or dBm units or as a ratio in % or dB u&s to the total input signal consisting of fundamental, harmonics and noise.

Operation

Section 3

3-22. Distartkm Merwrement Display Units.

Distortion measurements can be displayed in linear or bgadhmic units. Linear ratiometric measurements are displayed in 5% while logarithmic measurements are displayed in dB where 0.00 dB is referenced to 100.0 %. Distortion measurements can also be displayed as an absolute level in units of mV, V, dBV or dBm. The distortion level display mode is useful to measure noise level in the presence of a

TABLE 3-2. FUNCTION DISPLAY AND DATA ENTRY UNITS.

holding tone. The holding tone is removed by the notch filter

and the noise level alone is measured and displayed. In addition the frequency of the notch tilter can be displayed in Hz or kHz units. To select the distortion measurement function simply depress the DIST key which illuminates both the key’s LED and the KYBD legend in the ANALYZER display. The various display modes can then be selected by depre4sing the appropriate units associated with the desiied

Function Display Unit

Legends Keys

ANALYPR GROUP:

FREQ LEVEL

DIST

SINAD

Hz kI4z mVVdBVdBm mV V Hz k.Hz

%dBdBVdBm

d.B

Default Units

(ENTER Key)

mVVHzkHz V mV V dJ3 V mVVHzkHz %

%dB

mV V dB dB

S/N

RATIO

SOURCE GROUP:

PREQ FREQ STEP LEVEL

LEVEL STEP

SPCL

START

STOP

LOW

HIGH

BUWPRGM GROUP:

dJ3

%dB

HzkHz

HZkHZ

mVVdBVdBm mV V dB SPCL

mV V Hz kHz dBV dBm

mVVHz kHz dBV dBm

mV V Hz kHz %dBdBVdBm

mVV Hz kHz %dBdBVdBm

dB %dB no entry

HzkHi Hz HzkHz Hz

mV V dB mV V dB V ENTER dimensionless

mV V Hz kHz Hz dB

mVVHzkHz dB

mVVHzkHz V.

%dB mVVHzkHz V

%dB

no entry

ADRS PRGM

ADRS

PRGM

ENTER dimensionless ENTER dimensionless

3-7

sectioll3

TABLE 3-3. VALID FUNCTION ARGUMENT RANGE.

Operation

Function

ANALYZER GROUP:

FREQ LEVEL DIST

SINAD S/N

RATIO

SOURCE GROUP:

FREQ PREQ STEP LEVEL1

LEVEL STEP SPCL

START’

STOP’

LOW

HIGH

Argument Entry Error

Range

OmVto3OOV OmVto3OOV OmVto3CMV OtolOO%

-140 to 0.0 dB

5HztoMOkHz OmVto3OOV oto14OdB

no entry allowed

10HztolsOkHz Set source frequency 01 OHztol5OkHz Set frequency increment 02 0 mV to 16 V Set open circuit output level (lin) 03

-140 to 24.08 dBv Set open circuit output level (log) 03 OmVto16V Set level increment (lin) 04 oto14OdB Set level increment (log) 04 See TABLE 3-7 See TABLE 3-7 05

10 Hz to 150 kHz Set sweep start frequency 06 OmVto16V

-140 to 24.08 dBv Set sweep start level (log) 06

10Hztol5OkHz Set sweep stop frequency 07 OmVto16V Set sweep stop level (lin) 07

-140 to 24.08 dsv Set sweep stop level (log) 07

-3ooto3alv set low plot limit (lin) 08

-3ooooto3oooo% Set low plot limit (lin) 08

-140 to 49.54 dB Set low plot limit (log) 08

-49.54 to 140 dB Set low plot limit (S/N, SINAD) 08

-3ooto3ookHz Set low plot limit (lin) 08

-3ooto3ooV Set high plot limit (lin) 09

-3ooooto30000% Set high plot limit (lin) 09

-140 to 49.54 dB Set high plot limit (log) 09

-49.54 to 140 dB Set high plot limit (S/N, SINAD)

-3ooto3ookHz set high plot limit (lin) 09

Action

Set input level range Set input level range

Set input level range Set distortion range (Iin) Set distortion range (log) Set notch tune frequency Set input level range Set SLNAD range (log)

Set sweep start level (lin) 06

No.

12 l3 14 14 14 14 15

15 20 17

BUS/PRGM GROUP:

ADRS oto30 Set IEEE-488 bus address 10 PRGM oto99

NOTE 1 Amplitude values can be entered and disphyed in dBm units. The alhwabk argument range for dBm values varies bawd on the source and load impedance scttinp and is limited by the open-circuit voltage range.

3-8

Set store/recall location 11

Operation

section 3

display mode. For example, to select distortion level in logarithmic units (dBV or dRm) depress the DIST key followed in sequence by the mV or V keys aad the dR key. The mV or V keys select the distortion measurement to be displayed as aa absolute level aad the dR key converts the results to logarithmic units.

3-23. Special lMsto&m fimctioas 12 aad I3 are provided to preset aad hold specific input level and distortion ranges. Refer to paragraph 3-65. Special function 17 extends the measurements sampling

period to provide a more consistent reading ia the presence of noise Using special function 14, notch filter tuaiag can be held at specific frequencies to aid in tuning the notch filter in the event that a stable frequency measurement caa not be achieved or to enable notch 6lter tuning to frequencies other than the fuadarneatal. As with all amplitude measurement fuactioas, the rms, average, or quasi-peak detector type caa be selected using special function 70,71 or 72, respectively. Special functions 80 through 86 select logarithmic distortion level display traits in dBV or dRm.

3-24. SINAD Measurement Function.

measures SINAD (signal-to-noise and distortion) in the same

manner as the distortion measurement except that the notch

filter is tuned and held at the source frequency to permit

measurements in the presence of large amounts of noise. If an external oscillator is used, it must be tuned to within 3 %

of the source frequency setting. The AC measurement tech-

niques are similar to those used ia the level measurement

function yielding fast settled measurements. Measurement bandwidth is selectable to reject noise while accurately

preserving harmonic components. The combination of har-

moaics aad noise is displayed as a percentage of the total

input sigaal consisting of fundamental, harmonics aad noise

3-25. SINAD Measurement Display Units.

measurements are only displayed ia dB uaits. To select the SINAD measurement function simply depress the SINAD

key which illtmriaates both the key’s LED and the KYBD

legend in the ANALYZER display.

3-26. Special SINAD Measurement Modes. S

functions 12 aad 13 are provided to preset and hold specific

input level and SINAD ranges. Refer to paragraph 3-65.

Special function 17 extends the measurements sampling

period to provide more consistent readiags in the presence

of noise. When measuring large amounts of noise (0 to lOdI3

SINAD), the notch filter tuaing may become indeterminate

and causes the [ message to be displayed. Special

function I.5 is designed to disable the [x message ia this

circumstance. As with all amplitude measurement functions,

the rms, average, or quasi-peak detector type can be selected

using special fuactioa 70,71 or 72, respectively.

Measufement

Modes. Special

The Model 1121

SINAD

p e c i a 1

3-27. S/N Measurement Function.

measures S/N (signal-to-noise) by alternately tumiag the source output on aad off aad displaying the ratio of the two measurements. The those used by the level measurement mode. Measurement baadwidth is selectable using the filters to reject out of band noise or provide iadustry staadard weightiag characteristics.

measurement

3-28. S/N Measurement Display Unlts.

ments are oaly displayed ia dB traits. To select the S/N measurement function simply depress the S/N key which ilhmiaates both the key’s LED aad the KYBD legend ia the ANALYZER display.

The Model 1121

techniques are similar to

S/N measure-

3-29. Special SIN Meanurement Modes. Special func-

tioa 17 extends the measurements sampling period to provide more consistent readiags ia the presence of noise. Special

fuactioas 40 through 49

delay between the signal measurement and noise measuremeat to allow time for the device under test to respond to the change ia amplitude. As with all amplitude measurement functions, the rms, average, or quasi-peak detector type caa be selected usiag special functions 70,71, aad 72.

3-30.

Using the Ratio Mode.

measurement modes to be displayed as a relative value to a previous measurement value. Ia a ratiometric measurement, such as a flatness response, amplitude measurements at

various frequencies are displayed relative to a reference level

at a frequency of 1 kH2. Another example of a ratiometric measurement is the measurement of the percent of AC ripple on a DC level.

331. Ratio Measurement Display Units.

level measurements are displayed ia % or dI3 units whereas relative frequency measurements are displayed ia Hz or kHz. To select the ratio mode simply depress an aaalyzr measuremeat key such as LEVEL followed by the RATIO key. The LEDs of both keys will be illuraiaated along with the KYRD legend in the ANALYZER display. When the next measuremeat cycle is complete, the measurement value will become the ratio reference aad the display will iadicate 100.00 %, 0.00 dB or O.tXIO Hz depending on the previous log&ear display mode. Selection of display units can be made by depressing either the %, dB, kHz or Hz keys. On subsequent measuremeat cycles the results wilI be displayed relative to the

origiaal ratio reference. The RATIO key is aa alternate action key, therefore, depressing the RATIO key again will deselect the ratio mode, extinguish the key’s LED and return the display to the normal measurement mode. If another measurement function is selected while the ratio mode is active, the LED on the RATIO key will be extiagGhed but the ratio reference is preserved for the origiaal measurement function aad caa be reactivated by depressing the origiaal

measurement function key. The ratio mode is Gaited to only

are used to program the amount of

The Model 1121 enables all

Rat iomet ric

3-9

section 3

TABLE 3-4. INF’UT LEVEL, RANGES.

AC Level Ranges: DC Level Ranges: Distortion and SINAD

Input Level Ranges

operation

300.0 to 150.1 v

150.0 to 75.1 v

75.00 to 30.1 v

30.00 to 15.01 v

15.00 to 7.51 v

7.500 to 3.01 v

3.000 to 1.501 v

300.0 to 150.1 v

150.0 to 75.1 v

75.00 to 30.1 v

30.00 to 15.01 v

15.00 to 7.51 v

7.500 to 3.01 v

3.000 V and below

1500 to 751 mV

750.0 to 301 mV

300.0 to 150.1 mV

150.0 to 75.1 mV

75.00 to 30.1 mV

30.00 to 15.01 mV

15.00 to 7.51 mV

7.500 to 3.01 mV

3.000 to 1.501 mV

1.500 to 0.751 mV

0.7500 to 0.301 mV

0.3000 mV and below

one reference value and the old ratio reference is lost if the ratio mode is activated in an alternate measurement function.

3-32.

Using A~ly~er Filter+. The

ternate action keys which means they are “toggled” on and off with each key stroke. The optional filters are mutually exclusive; therefore, depressing one of the keys will cancel the other. The same is true of the low-pass filters, only one low-pass filter can be used at a time. The DC filter, however, is mutually exclusive with all filters and will also be canceled by selecting any measurement functions other than Level.

3-33. The minimum bandwidth consistent with the measure-

ment bandwidth should be used to minim& noise errors. For

example, when measuring the distortion of a 1 kHx fun-

damental tone, the 30 kHx low-pass tilter is recommended. The DC low-pass filter is provided to attenuate all AC components and measure DC level directly. The DC low-pass filter can only be activated in the analyxer level mode. Bandpass lilters are combiitions of high- and low-pass filters and

are used in some measurements to simulate the sensitivity of the human ear to the audible frequency spectrum. High-pass filter selection is used to eliminate power line harmonics when present. The 400 Hz high-pass filter typically provides

audio filter keys are al-

300.0 to 150.1 v

150.0 to 75.1 v

75.00 to 30.1 v

30.00 to 15.01 v

15.00 to 7.51 v

7500 to 3.01 v

3.000 to 1.501 v 1500 to 751 mV

750.0 to 301 mV

300.0 to 150.1 mV

150.0 to 100.1 mV

100.0 to 50.1 mV

50.0 mV and below

more than 80 dB of attenuation at 60 Hz.

3-34. The CCIR filter is a special case since its application

depends on whether the average or quasi-peak detector is selected. The CCIR r ecommendation 468-3 specifies the

filter should be used with the quasi-peak detector. Another

application referred to as the CCIR/ARM calls for using the

average responding meter (ARM) and applying a gain correction value of -6.6 dB. The Model 1121 wiU accommodate both applications. The average selected using special readings will also be adjusted by -6.6 dB automatically when the average detector is selected.

3-35.

Audio Oscillator

Model 1121 contains a variable frequency, low distortion audio oscillator and a precision progranunable amplifier/attenuator. The oscillator frequency tuning uses a frequency lock technique under microprocesso accuracy and resolution. The output level can be varied in very fme increments over a wide range of levels. Levels can

be set in either linear or logarithmic units to accommodate

existing test procedures and applications. The oscillator incorporates a user confiigurable sweep mode which can be

function

quasi-peak detector can be

71 or 72 respectively. The level

General

Descripth.

r control to yield high

The

3-10

Operation

TABLE 3-5. DISTORTION AND SINAD RANGES.

section 3

Linear:

100.0 to 50.01%

50.00 to 20.01%

20.00 to 10.01%

10.00 to 5.001%

moo to 2.001%

2.000 to 1.001%

1.000 to 0.5001 %

o.moo to 0.2001 %

0.2000 to 0.1001 %

0.1000 to 0.05001%

0.05000 to 0.02001 %

0.02000 to 0.01001%

0.01000 % and below

programmed to sweep frequency or level in logarithmic or linear increments.

3-34. Oscillator Output Description.

figuration of the Model 1121 can be selected for single-ended or balanced/floating operation using the FLOAT key. Special functions 75,76, and 77 select the respective 50 ohm, IS0 ohm, and 600 ohm source output impedance.

The output con-

Logarithmic:

0.00 to -6.01 dB

-6.02

-1T.97 dB

* -13.98 to -19.99 dB

-20.00 to -26.01 dB

-26.02 to -33.97 dB

-33.98 to -39.99 dB

-40.00 to 46.01 dB

46.02 to -53.97 dB

-53.98 to -59.99 dB

-60.00 to -66.01 dB

-66.02 to -73.97 dB

-73.98 to -79.99 dB

-80.00 dB and below

3-39. When a frequency setting is entered the oscillator is

coarse tuned to the setting by the control program. Thereafter, the internal frequency of the oscillator is measured and fme adjustments are made by the control program to tune the oscillator to within tolerance. Special function 16 disables the frequency lock mode to enable faster frequency updates and sweep rates where the full frequency accuracy of the oscillator is not required.

3-37. Source Frequency Display and Selection.

select the Frequency hrnction simply depress the FREQ key. The key’s LED and the KYBD legend will be illuminated and the SOURCE display window will contain the current frequency setting. Once the function is selected a new frequency may be entered using the DATA ENTRY keypad. Display units can be selected by depressing either the Hz or kHz keys.

3.38, Source Frequency Lock Mode Description.

Model 1121 source oscillator achieves high frequency accuracy and resolution through the use of a frequency lock technique. The design of the Model 1121 enables internal measurement of the oscillator frequency. During initialization after power is applied or when the LCIANIT key is depressed, the oscillator is sequenced through its live frequency bands and specific frequencies settings are verified for accuracy. Tuning errors are stored by the control program

in internal memory as calibration factors. If the oscillator fails to function on any of the frequency bands, an error (30-34)

will be displayed as an indication of a hardware fault requir-

ing service.

The

3-40. Source Level Display And Selection.

the Level function simply depress the LEVEL key. The key’s LED and the KYBD legend will be illuminated and the LEVEL display window will contain the current level setting.

Once the function is selected a new level maybe entered using the DATA ENTRY keypad. The level function allows display and selection of the open-circuit output level. When a level is selected, the programmable amplifier/attenuator is configured by the microprocessor circuits to one of the ranges listed in Table 3-6. Special function 18 disables the automatic range selection and holds the range that is active at the time

the special function was enabled. When the range-hold mode is active, new levels may be entered from 0 V up to the maximum value for the selected range. This mode provides the abiity to set levels over a wide dynamic range without the possible delay and transients associated with range to range transitions. The LEVEL function can be incremented or

decremented by the value in the LEVEL STEP function.

341. Amplitude Display Units.

LEVEL, START and STOP functions may be displayed in linear units of mV or V or as a logarithmic value in units of dBV or dBm. Display units can be selected by depressing

Amplitude values for the

To select

3-11

Section

Operation

either the mV, V, or dB keys. Special functions 80 through 86 select the logarithmic display mode where 80, dRV, is the

default selection. The dBV display mode converts the linear voltage display (open-circuit) to a logarithmic value relative to 1,000 V rms. When a dBm mode is selected, the actual power into the load is calculated and displayed based on the open-circuit level and source and load impedance selections,

342.

Step Size and Step Key Operation. The keys marked with up and down arrows are used to increment and decrement source and program function values in the active

window designated by the KYBD legend. If an arrow key is constantly depressed, the stepping will repeat. Functions which can be stepped are PRGM, FREQ, START, STOP, and LEVEL. Stepping any other function has no effect.

343. Increment/Decrement Program Number. The Program number can be stepped in single increments. A special Auto-recall function is provided which automatically executes the recall operation after the program location function has been incremented or decremented with the step keys. This function allows rapid recall of sequential program setups by using a single key or bus mnemonic. The auto-recall function can be enabled or disabled using the internal option switch A4Sl-5 or special functions 7 and 8.

corder. The analyzer measurement provides the Y axis information. The Y axis scale can be set using the HIGH and LOW

plot limit functions.

347. SWEEP Key Description. The SWEEP key is an alternate action key which initiates and terminates the sweep.

The key’s LED indicates a sweep is in progress and will be

illuminated for the period of one sweep.

348. START Key Description. The START key allows

entry of either the frequency or level START value. The START value defines the origin of the X axis which corresponds to 0 volts at the X AXIS output connector. When the START key is depressed the SOURCE display will contain the START value and 0 volts is presented at the X AXIS output connector as an aid in setting the offset adjustment on most X-Y plotters.

349.

STOP Key Description. The STOP key allows entry of either the frequency or level STOP value. The STOP value defmes the end of the X axis which corresponds to 5 volts at the X AXIS output connector. When the STOP key is depressed the SOURCE display will contain the STOP value and 5 volts is presented at the X AXIS output connector as an aid in setting the sensitivity adjustment on most X-Y plotters.

3-M. Increment/Decrement Frequency Values.

Frequency values in the FREQ, START, and STOP functions can be stepped by the value in the FREQ STEP function. Available frequency step sixes are listed in Table 3-3. If the step size is smaller than the resolution of the selected func-

tion, the function will be stepped by the resolution value. The frequency step size also functions as the step size for the linear frequency sweep mode.

34. Increment/Decrement Level Values.

Amplitude

values in the LEVEL, START, and STOP functions can be stepped by the value in the LEVEL STEP function. Level step sixes can be linear or logarithmic values. Available level step sixes are listed in Table 3-3. If the step size is smaller than the resolution of the selected function, the function will be stepped by the resolution value. Table 3-6 lists the output level ranges and resolution. The level step size also functions as the step size for the linear and logarithmic level sweep modes.

346. Sweep Mode General Description. The Model

1121

provides a user programmable sweep capability which simplifies time consuming measurements such as flatness, distortion vs. power output and compression/expansion linearity.

the sweep mode the

source

the

Model

1121 is

used as the stimulus and can be configured to sweep frequency or level in linear or logarithmic steps. The source provides the X axis and pen control signals for an external plotter/re-

3-50. X AXIS Output Description. The X AXIS output of the Model 1121 is the scaled result of the sweep frequency or level relative to the START and STOP values. The Model 1121 can be swept in level or frequency with 4096 points of resolution on the X axis. Selection of a level or frequency sweep is determined by the type of START and STOP values entered: START and STOP level entries designate a level sweep and START and STOP frequency entries designate a frequency sweep.

3-51. Y AXIS Output Description. The Y AXIS output of the Model 1121 is the scaled result of the analyzer measurement value relative to the HIGH and LOW values. There are 4096 points of resolution between 0 and 5 volts on the Y axis. Any measurement mode can be used for sweeping. Various measurement modes and applications require greater measurement settling before a data point is generated. The Model 1121 allows for user configurable settling times using special functions 61 through 69. The settling time is based on the number of consecutive measurement cycles achieved before a data point is plotted. Special function 60 disables the analyzer measurement and the Y AXIS output and allows the source to be used as a rapid incremental sweep generator with X AXIS and PEN control.

3-52. The HIGH and LOW plot limits are always displayed in the same units as the analyzer measurement mode. The Y AXIS output will be scaled linearly or logarithmically

3-12

+ 137 hidden pages

Boonton 1121 Instruction Manual

Specifications and Main Features

Frequently Asked Questions

User Manual