Page 3 - Contents; Operating the Probe; Calibration Tests; Service; Introduction
Contents 3 1 Operating the Probe Accessories Supplied 6 Accessories Available 8 To inspect the probe 9 Using the probe with other instruments 9 Recommended Test Equipment 9 2 Calibration Tests and Adjustment Equipment Required 26 The Test Board 26 Calibration Tests 27 dc Gain Accuracy 28 Bandwidth 3...
Page 4 - Theory of Operation
4 Contents Theory of Operation 59 Differential Probe 60 Control and Power Module 60 Attenuator Adapters 61 Test Board 62 Service Policy 63 Troubleshooting 64 Probe Troubleshooting 64 Probe Control and Power Module Troubleshooting 64 Removing and Replacing Assemblies 66 Differential Probe 66 Probe Ad...
Page 5 - Operating the Probe
Page 6 - Accessories Supplied; Item
6 Operating the Probe Accessories Supplied Introduction This chapter shows you how to connect and operate the 1141A Differential Probe and 1142A Probe Control and Power Module as a differential probe system. Accessories Supplied The following items are supplied as part of the 1141A/1142A probe syste...
Page 8 - Accessories Available; The following accessories can be ordered.
8 Operating the Probe Accessories Available Figure 1-2 1141A Miscellaneous Accessories Figure 1-3 1142A Probe Control and Power Module Accessories Available The following accessories can be ordered. • 5959-9335 Long Extension Lead (5.5 inch/14 cm), package of 5 • 5090-4833 Mini grabber for SMT, pack...
Page 9 - To inspect the probe; Recommended Test Equipment; Signal Generator; Function Generator
9 Operating the Probe To inspect the probe To inspect the probe Inspect the shipping container for damage. If the shipping container or cushioning material is damaged, it should be kept until the contents of the shipment have been checked for completeness and the instrument had been checked mechanic...
Page 10 - Setting up the probe; Power Requirements
10 Operating the Probe Recommended Test Equipment Setting up the probe The following paragraphs cover system preparation and initial adjustments. Power Requirements The 1141A/1142A probe system (specifically the 1142A) requires a power source of either 90 to 132/198 to 264 Vac, 47 to 440 Hz, 25 VA m...
Page 11 - W A R N I N G; If the oscilloscope does not have a selectable 50; Initial Adjustment
11 Operating the Probe Recommended Test Equipment W A R N I N G Before connecting this instrument, the protective earth terminal of the instrument must be connected to the protective conductor of the (Mains) power cord. The Mains plug must be inserted in a socket outlet provided with a protective ea...
Page 12 - Equipment Needed; The following equipment is necessary for initial adjustment.; • 5 V power supply; termination on the test board.; Use the probe setup procedure to set up the probe system.
12 Operating the Probe Recommended Test Equipment • Offset null zeroes the dc level at the output of the probe. The range of adjustment is about ±4 mV. • DC Reject Gain adjusts the gain of the dc reject circuit to accurately null the dc component of an input signal. The range of adjustment is about ...
Page 13 - Set the Local/Remote push button to Local.; Set the power supply output to 5 V.; Warm up the 1141A for 30 minutes before making adjustments.; Using the Accessories
13 Operating the Probe Recommended Test Equipment 5 Set up the 1142A: a Set the Local/Remote push button to Local. b Under DC Couple, press Zero offset. 6 Set the power supply output to 5 V. 7 Arrange a connection between the power supply and the test board. The negative terminal of the supply shoul...
Page 14 - Probe Tips; the extension leads to the probe.
14 Operating the Probe Recommended Test Equipment Figure 1-7 Basic Accessory Connections Probe Tips Probe tips fit into the receptacles in the probe and are held in place with probe tip caps. If necessary, you can solder the probe tips into a circuit or wires can be soldered to the tips. If you sold...
Page 15 - N o t e; • Connect the leads at right angles to the circuitry under test.; Remove the probe tip caps and tips.
15 Operating the Probe Recommended Test Equipment N o t e Use extension leads and similar connection accessories carefully. Extension leads compromise the high-frequency specifications of the probe. CMRR is particularly sensitive to unbalanced input parameters. To prevent pickup of stray fields when...
Page 16 - Adapters
16 Operating the Probe Recommended Test Equipment Adapters There are three adapters for use with the differential probe. Two adapters are attenuators, a 10x and a100x. The other is an ac adapter for blocking dc from the probe input. The adapters are installed on the probe after the probe tip caps an...
Page 17 - Adapter Combinations
17 Operating the Probe Recommended Test Equipment Adapter Combinations The figure below shows the allowed adapter and probe connections. There are two specific combinations that should not be used. • Do not attach the ac adapter between an attenuator adapter and the probe. An attenuator adapter must...
Page 18 - Connector Compatibility; Grounding; Coupling Functions
18 Operating the Probe Recommended Test Equipment Connector Compatibility The following are general connector characteristics for the probe, adapters, and accessories. • The female connectors on the probe, adapters, and other accessories are designed to mate with 0.030-inch round or 0.0250-inch squa...
Page 19 - Probe System Coupling Functions; The key characteristics are:; dc offset
19 Operating the Probe Recommended Test Equipment Probe System Coupling Functions dc Reject dc Reject is the best method of eliminating the dc component of a signal when dc is not a factor in the measurement. The key characteristics are: • The low-frequency component (from dc to the selected corner ...
Page 20 - Remove the ac adapter if it is installed.; C A U T I O N
20 Operating the Probe Recommended Test Equipment To use dc reject: 1 Remove the ac adapter if it is installed. 2 On the front panel of the 1142A, press Local. 3 Under DC Reject on the front panel, press 5.0 Hz or 0.5 Hz individually, or 5.0 Hz and 0.5 Hz simultaneously to get 0.05 Hz. Within the fr...
Page 21 - On the 1142A, press Local and Zero offset.; Remote operation; The following table gives the connections.
21 Operating the Probe Recommended Test Equipment To use ac coupling: 1 Attach the ac coupling adapter to the input of the probe or the input of the attenuator adapter. 2 On the 1142A, press Local and Zero offset. Remote operation For automatic test applications, the coupling and offset functions pr...
Page 22 - Function Select; Cleaning Requirements; Hz Reject
22 Operating the Probe Recommended Test Equipment Function Select The easiest way to control the function select lines is contact closures between the lines and Digital common (pin 2) of the remote input connector. (TTL compatible control signals can be used; but to avoid problems with ground loops,...
Page 23 - Differential Amplifiers and CMRR; The following things can affect the effective CMRR of a test setup:
23 Operating the Probe Recommended Test Equipment Differential Amplifiers and CMRR The 1141A Differential Probe is a high-impedance differential amplifier. A characteristic of differential amplifiers is the ability to reject signals that are common to the two inputs. The common mode rejection ratio ...
Page 25 - Calibration Tests and Adjustment
Page 26 - Equipment Required; termination (two 100; The power rating of the 50
26 Calibration Tests and Adjustment Equipment Required Introduction This chapter is divided into two sections. The first section gives calibration tests and the second adjustment procedures for the 1141A Differential Probe and 1142A Probe Control and Power Module. Equipment Required A complete list ...
Page 27 - The Test Board; Testing Interval; Procedures may be done individually or in any order.; N O T E
27 Calibration Tests and Adjustment The Test Board Calibration Tests These procedures test the probe’s electrical performance using applicable specifications given in “Performance Specifications and Characteristics” on page 55 as performance standards. Specifications applicable to individual tests a...
Page 28 - dc Gain Accuracy; DVM
28 Calibration Tests and Adjustment dc Gain Accuracy dc Gain Accuracy This test checks the dc gain accuracy of the differential probe and the dc accuracy of the differential probe with attenuator and adapters. Specification: Probe alone, ±2%; with attenuator adapter, ±4% Equipment Required Probe Gai...
Page 30 - Calculate probe gain as; o u t
30 Calibration Tests and Adjustment dc Gain Accuracy Figure 2-3 Signal to - input 10 Calculate probe gain as Record the result of this calculation in the “Calibration Test Record” on page 39. To pass this test, the probe gain = 0.98 to 1.02 N O T E Failure of the gain accuracy test can be caused by ...
Page 32 - 00x Attenuator Accuracy Test
32 Calibration Tests and Adjustment dc Gain Accuracy 100x Attenuator Accuracy Test N O T E If the gain test for the probe fails, it will be reflected in the test for the 100x attenuator adapter. Do not continue until the probe passes the gain test. 1 Disconnect the probe/attenuator from the test boa...
Page 33 - Record the V
33 Calibration Tests and Adjustment dc Gain Accuracy 6 Carefully connect the input of the probe/attenuator to the test board in the position shown in the figure below (signal to - input). Figure 2-7 Signal to - input 7 Record the V out2 measurement from the bottom DVM in figure 2-2. 8 Calculate the ...
Page 34 - Bandwidth; Specification
34 Calibration Tests and Adjustment Bandwidth Bandwidth This test checks the high-frequency response of the 1141A Differential Probe. The bandwidth of the oscilloscope is characterized first so it is not a factor in the measurement. Specification (-3dB, dc coupled): dc to 200 MHz Equipment Required ...
Page 35 - Reconfigure the equipment.
35 Calibration Tests and Adjustment Bandwidth 6 Reconfigure the equipment. a Disconnect the signal generator cable from the oscilloscope input and connect it to the test board. b Connect the output of the differential probe to the channel 1 input of the oscilloscope. c Carefully connect the input of...
Page 36 - CMRR Test; This test checks the CMRR at 1 MHz and 100 MHz.; Critical Specifications
36 Calibration Tests and Adjustment CMRR Test CMRR Test This test checks the CMRR at 1 MHz and 100 MHz. Specification 3000:1 at 1 MHz, 10:1 at 100 MHz Equipment Required Procedure 1 Connect the probe power connector to the PROBE connection on the rear of the 1142A Probe Control and Power Module. 2 S...
Page 37 - Disconnect the probe amp from the test board and measure V; on; TIMEBASE
37 Calibration Tests and Adjustment CMRR Test 7 On the oscilloscope, press AUTOSCALE and set the following parameters. 8 On the oscilloscope, measure the peak-to-peak voltage of the channel 1 signal, then V P-P, then press 1) and record the reading.V p-p (1) = _____________ mV 9 Connect the input of...
Page 38 - CMRR
38 Calibration Tests and Adjustment CMRR Test 15 Connect the input of the probe to the test board in the position shown in the figure below (signal to + input). Figure 2-11 Signal to + input 16 Set the signal generator for 100 MHz at 0.0 dBm (about 224 mV rms , 632 mV p-p ). 17 Set the oscilloscope ...
Page 39 - Calibration Test Record; Recommended Test Interval - 1 Year/2000 hours
39 Calibration Tests and Adjustment Calibration Test Record Calibration Test Record 1141A/1142A Differential Probe Tested by_________________________ Serial No. ______________________________ Work Order No.____________________ Recommended Test Interval - 1 Year/2000 hours Date____________________ Re...
Page 40 - Adjustments; Adjustment Interval; Probe Adjustment; Do these adjustment procedures in an ESD-safe area.
40 Calibration Tests and Adjustment Probe Adjustment Adjustments This section provides adjustment procedures for the 1141A Differential Probe and attenuator adapters. There are no service adjustments for the 1142A Probe Control Module. Adjustment Interval None of the adjustment procedures that follo...
Page 41 - Handle the PC assembly by the edges of the PC board.
41 Calibration Tests and Adjustment Probe Adjustment The following equipment is required for this procedure. Procedures are based on the model or part number recommended. Equipment Required Probe Preparation The probe cover must be removed before adjustment. Drift due to temperature differences with...
Page 42 - Connect the mains power to the 1142A.; Adjustment Procedure; HF Gain and HF CMRR; • Sine wave
42 Calibration Tests and Adjustment Adjustment Procedure 6 As shown in the figure below, use the grounding screw to reinstall the ground block on the PC assembly. Figure 2-13 Attaching Ground Block to Probe PC Assembly The ground block provides a mechanical and electrical connection when the probe P...
Page 43 - Connect the output of the probe to the channel 1 input.
43 Calibration Tests and Adjustment Adjustment Procedure 3 On the oscilloscope, then press CLEAR DISPLAY. Press AUTOSCALE, then set up the following parameters. 4 On the oscilloscope, measure the peak-to-peak voltage of the channel 1 signal and record the reading.V p-p (1) = _____________ mV 5 Disco...
Page 44 - Adjust R9, HF GAIN so the V; Set the function generator output to 1.0 V; • Square wave
44 Calibration Tests and Adjustment Adjustment Procedure 8 Center adjustment R11, HF CMRR (see following figure). Figure 2-15 R11, HF CMRR Adjustment 9 Adjust R9, HF GAIN so the V p-p (1) measurement is the same as in step 4, within ±0.5%. Make the adjustment slowly so the oscilloscope display has t...
Page 45 - Change the oscilloscope settings to:; Menu
45 Calibration Tests and Adjustment Adjustment Procedure 2 Change the oscilloscope settings to: 3 Carefully connect the input of the probe to the test board in the position shown in the figure below (signal to + input). Figure 2-17 Signal to + input 4 Adjust R14 (LF Gain) and C4 (+ LF BANDWIDTH) for...
Page 46 - Change the function generator settings to:
46 Calibration Tests and Adjustment Adjustment Procedure 5 Carefully connect the probe to the test board in position shown in the figure below (signal to both inputs). Figure 2-19 Signal to both inputs 6 Change the function generator settings to: • Sine wave • 4 kHz • 1.0 V p-p 7 Change the oscillos...
Page 47 - High Frequency Compensation; , or as close to that as possible. Adjust slowly and press; The minimum allowable amplitude is 212 mV; Probe Reassembly
47 Calibration Tests and Adjustment Adjustment Procedure High Frequency Compensation This adjustment sequence continues from the Low Frequency Response and CMRR adjustment. However, it can be done separately if the probe meets all specifications except bandwidth. Adjust R13 for unity gain at 200 MHz...
Page 48 - Assemble the PC assembly in the top cover.; Position the ground block at the center-front of the PC assembly.; Replace the bottom cover.; Close the two covers together and fasten with the probe clamp ring.
48 Calibration Tests and Adjustment Adjustment Procedure 4 Assemble the PC assembly in the top cover. The side of the PC assembly with the large hybrid is exposed when the assembly is in the top cover. The figure below shows how the top cover, PC board, and ground block fit together. Figure 2-22 Rea...
Page 49 - Attenuator Adapter Adjustment; • If an adapter is suspected of needing adjustment.
49 Calibration Tests and Adjustment Attenuator Adapter Adjustment Attenuator Adapter Adjustment The following procedure should be used if it is necessary to adjust an attenuator adapter. Attenuator adapters have only characteristics; they do not have any specifications. An adapter will need adjustme...
Page 50 - Set up the oscilloscope, then set the following parameters.
50 Calibration Tests and Adjustment Attenuator Adapter Adjustment Adjustment Procedure N O T E The attenuator must be adjusted when installed on the 1141A probe with which it will be used. The specifications and characteristics will not be met if the attenuator adapter is adjusted with one different...
Page 51 - Change the function generator to 10 V
51 Calibration Tests and Adjustment Attenuator Adapter Adjustment 7 Connect the adapter/probe combination to the test board in the position shown in the figure below. Figure 2-23 Signal to + input 8 Adjust the + HF RESP for best overall pulse response, the flattest pulse top. Use the figure below fo...
Page 53 - Service
Page 55 - Performance Specifications and Characteristics
55 Service Performance Specifications and Characteristics Performance Specifications and Characteristics The following table gives performance specifications used to test the 1141A and 1142A. It also gives performance characteristics that are typical for the probe system. Performance Specifications ...
Page 56 - Legend; CMRR specification for probe with no input adapters.
56 Service Performance Specifications and Characteristics Figure 3-1 CMRR Specifications and Characteristics Legend A. CMRR specification for probe with no input adapters. B. Low-frequency CMRR specification for probe with the ac adapter. C. Typical CMRR characteristic for differential probe with no...
Page 57 - Input voltage limits for probe alone.
57 Service Performance Specifications and Characteristics Figure 3-2 Maximum Input Voltage vs. Frequency Legend A. Input voltage limits for probe alone. B. Input voltage limits for 10x adapter. C. Input voltage limits for 100x adapter.
Page 58 - General Characteristics; Refer to the outline drawings below.
58 Service General Characteristics General Characteristics The following characteristics apply to the 1141A Differential Probe with the 1142A Probe Control and Power Module. Figure 3-3 Mechanical Dimensions Environmental Conditions Operating Non-operating Temperature 0°C to +55 C° (32°F to +131°F) -...
Page 60 - Differential Probe; input impedance for the probe. The LOW FREQ BANDWIDTH; Summing Amp; Control and Power Module
60 Service Theory of Operation Differential Probe The probe contains a two-path differential amplifier with unity gain. It is implemented on a double-sided surface-mount PC board with the high-frequency path on one side and the low-frequency path on the other. The two paths are split directly after ...
Page 61 - Offset Functions; Attenuator Adapters
61 Service Theory of Operation Offset Functions There are two offset functions developed in the control module: variable offset and dc reject. A variable offset voltage with coarse and fine adjustments can be selected by the front panel controls. The offset level is buffered by U8 and selected by mu...
Page 62 - Test Board
62 Service Theory of Operation Test Board The test board is a device for conveniently connecting test signals to the differential probe. The probe can be connected to the board with the signal to the positive, negative, or both inputs. Figure 3-6 Test Board Schematic
Page 63 - Service Policy
63 Service Service Policy Service Policy For parts of the 1141A/1142A probe system that are complex, the service policy is for assembly-level repair. For parts of the system with simple circuitry, the service policy is component-level repair. The service policy for the 1141A Differential Probe is as...
Page 64 - Troubleshooting; Probe Troubleshooting; To troubleshoot the probe:; Apply a known signal to the input of the probe.
64 Service Troubleshooting Troubleshooting Use the following paragraphs to assist in troubleshooting problems with the 1141A/1142A Differential Probe. Probe Troubleshooting To troubleshoot the probe: 1 Apply a known signal to the input of the probe. 2 Check for an identical output at the output coax...
Page 66 - Removing and Replacing Assemblies; Remove the ground screw on the top of the probe.; Disconnect the cable connector from the probe PC board.
66 Service Removing and Replacing Assemblies Removing and Replacing Assemblies This section contains procedures for the removal and replacement of major assemblies. C A U T I O N Never remove or install any assembly with the instrument power ON. Component damage can occur. Differential Probe Use the...
Page 67 - Reassemble Probe; Position the ground block at the front of the PC assembly.
67 Service Removing and Replacing Assemblies Reassemble Probe The ground screw passes through the top cover and PC board and screws into the ground block. 1 If replacing the PC board, remove the input connectors from the old board and put them on the new one. 2 If replacing the cable, note the orien...
Page 68 - Probe Adapters; Disassemble Adapter; Reassemble Adapter
68 Service Removing and Replacing Assemblies C A U T I O N Note where the two pins at the rear of the top cover enter the holes in the PC assembly. Position the cable wires away from these two areas. When the bottom cover is closed, part of it will pinch wires that are laying over these areas. b Ins...
Page 70 - Probe Control and Power Module; • Three directly on the PC board.; Reverse the procedure to reassemble the control and power supply.
70 Service Removing and Replacing Assemblies Probe Control and Power Module Use the following procedure to disassemble the probe control and power module. W A R N I N G Hazardous voltages exist on the power supply. To avoid electrical shock, adhere closely to the following procedures. 1 Remove the p...
Page 71 - Replaceable Parts; Parts List; • Reference designator; Ordering Information
71 Service Replaceable Parts Replaceable Parts This section contains information for ordering parts. Service support for the 1141A Differential Probe is to the assembly level. Service support for the adapters is as complete assemblies, except for the probe tip caps and the probe tips. Service suppor...
Page 72 - Manufacturers’ Codes; Manufacturers’ Code List; Name; Any satisfactory supplier
72 Service Replaceable Parts Mail order forms and specific ordering information are available through your local Agilent Technologies Sales Office. Addresses and telephone numbers are located in a separate document shipped with the manuals. Manufacturers’ Codes A list of manufacturers’ codes is give...
Page 73 - Exploded View
73 Service Replaceable Parts Exploded View Figure 3-11 1141A Differential Probe Parts
Page 76 - IC Connectors not Shown; GND
76 Service Replaceable Parts Figure 3-14 1142A Probe Control and Power Module IC Connectors not Shown Supply Pin No. IC Group +15 14 U3 -15 3 GND 15 +15 7 U6-8, 11 -15 4 NC 1, 5, 8 +5 16 U9 GND 8
Page 79 - PC ASSEMBLY-POWER AND CONTROL
79 Service Replaceable Parts A1 01142-66501 1 PC ASSEMBLY-POWER AND CONTROL 28480 01142-66501 H1 0515-0374 7 SCREW-MACHINE M3 10mm-LG 00000 ORDER BY DESP. H2 0515-1031 4 SCREW-MACHINE M3 6mm-LG 90-DEG-FLH-HD 00000 ORDER BY DESP. H3 0515-1579 1 SCREW-MACHINE M5 18mm-LG 00000 ORDER BY DESP. MP1 01142-...
Page 80 - Prefix the reference designators with A1
80 Service Replaceable Parts Power Supply Replaceable Parts Ref. Des. Part Number Qty Description Mfr. Code Mfr. Part Number Prefix the reference designators with A1 C1 0160-6190 2 CAPACITOR-FXD 0.33UF ±10% 50VDC 28480 0160-6190 C2 0160-5474 1 CAPACITOR-FXD 0.1UF ±5% 100VDC MET-POLY 28480 0160-5474 ...
Page 83 - NOT ASSIGNED; Power Supply Replaceable Parts
83 Service Replaceable Parts R16 0698-6317 2 RESISTOR 500 0.1% 0.125W TF TC=0±25 28480 0698-6317 R17 0698-4002 RESISTOR 5K 1% 0.125W TF TC=0±100 24546 CT4-1/8-TO-5001-F R18 0699-1203 RESISTOR 120.0 1% 0.125W TF TC=0±25 28480 0699-1203 R19 0698-6317 RESISTOR 500 0.1% 0.125W TF TC=0±25 28480 0698-6317...
Page 84 - RESISTOR NETWORK
84 Service Replaceable Parts RP1 1810-1242 1 RESISTOR NETWORK 28480 1810-1242 S1 3101-2609 1 SWITCH-SL DPST STD 5A 250VAC PC 28480 3101-2609 S2 3101-3007 1 SWITCH-6 STATION ASSEMBLY 28480 3101-3007 T1 9100-4750 1 TRANSFORMER-POWER (with mtg. hardware) 28480 9100-4750 U1 1826-1403 2 IC V RGLTER-ADJ-P...
Page 87 - Index; Numerics
Index 87 Numerics 100x attenuator test , 32 10x attenuator test , 30 A ac adapter , 20 ac coupling adapters , 19 ac low frequency , 55 accessories available to order , 8 circuit connector posts , 15 extension leads , 14 ground leads , 14 mini grabbers , 15 probe tips , 14 shielded signal leads , 15 ...
Page 89 - Notices; Manual Part Number; Warranty
Agilent TechnologiesP.O. Box 21971900 Garden of the Gods Road Notices © Agilent Technologies, Inc. 2000-2004 No part of this manual may be reproduced in any form or by any means (including electronic storage and retrieval or translation into a foreign language) without prior agreement and written co...
Page 90 - Warnings; To clean the instrument
Product Safety Notices This apparatus has been designed and tested in accordance with IEC Publication 1010, Safety Requirements for Measuring Apparatus, and has been supplied in a safe condition. This is a Safety Class I instrument (provided with terminal for protective earthing). Before applying po...