Keysight U2761A USB Modular Function/Arbitrary Waveform

Keysight U2761A USB
Modular Function/Arbitrary
Waveform Generator
Service Guide
Notices
Copyright Notice
© Keysight Technologies 2008 - 2017
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 consent from
Keysight Technologies as governed by
United States and international
copyright laws.
Trademarks
Pentium is a U.S. registered trademark
of Intel Corporation.
Microsoft, Visual Studio, Windows, and
MS Windows are trademarks of
Microsoft Corporation in the United
States and/or other countries.
Manual Part Number
U2761-90010
Edition
Edition 8, June 1, 2017
Printed in:
Printed in Malaysia
Published by:
Keysight Technologies
Bayan Lepas Free Industrial Zone,
11900 Penang, Malaysia
Technology Licenses
The hardware and/or software
described in this document are
furnished under a license and may be
used or copied only in accordance with
the terms of such license.
Declaration of Conformity
Declarations of Conformity for this
product and for other Keysight
products may be downloaded from the
Web. Go to http://www.keysight.com/
go/conformity. You can then search by
product number to find the latest
Declaration of Conformity.
2
U.S. Government Rights
Warranty
The Software is “commercial computer
software,” as defined by Federal
Acquisition Regulation (“FAR”) 2.101.
Pursuant to FAR 12.212 and 27.405-3
and Department of Defense FAR
Supplement (“DFARS”) 227.7202, the
U.S. government acquires commercial
computer software under the same
terms by which the software is
customarily provided to the public.
Accordingly, Keysight provides the
Software to U.S. government
customers under its standard
commercial license, which is embodied
in its End User License Agreement
(EULA), a copy of which can be found
at http://www.keysight.com/find/
sweula. The license set forth in the
EULA represents the exclusive authority
by which the U.S. government may use,
modify, distribute, or disclose the
Software. The EULA and the license set
forth therein, does not require or
permit, among other things, that
Keysight: (1) Furnish technical
information related to commercial
computer software or commercial
computer software documentation that
is not customarily provided to the
public; or (2) Relinquish to, or
otherwise provide, the government
rights in excess of these rights
customarily provided to the public to
use, modify, reproduce, release,
perform, display, or disclose
commercial computer software or
commercial computer software
documentation. No additional
government requirements beyond
those set forth in the EULA shall apply,
except to the extent that those terms,
rights, or licenses are explicitly required
from all providers of commercial
computer software pursuant to the FAR
and the DFARS and are set forth
specifically in writing elsewhere in the
EULA. Keysight shall be under no
obligation to update, revise or
otherwise modify the Software. With
respect to any technical data as
defined by FAR 2.101, pursuant to FAR
12.211 and 27.404.2 and DFARS
227.7102, the U.S. government
acquires no greater than Limited Rights
as defined in FAR 27.401 or DFAR
227.7103-5 (c), as applicable in any
technical data.
THE MATERIAL CONTAINED IN THIS
DOCUMENT IS PROVIDED “AS IS,”
AND IS SUBJECT TO BEING
CHANGED, WITHOUT NOTICE, IN
FUTURE EDITIONS. FURTHER, TO THE
MAXIMUM EXTENT PERMITTED BY
APPLICABLE LAW, KEYSIGHT
DISCLAIMS ALL WARRANTIES, EITHER
EXPRESS OR IMPLIED, WITH REGARD
TO THIS MANUAL AND ANY
INFORMATION CONTAINED HEREIN,
INCLUDING BUT NOT LIMITED TO THE
IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE. KEYSIGHT
SHALL NOT BE LIABLE FOR ERRORS
OR FOR INCIDENTAL OR
CONSEQUENTIAL DAMAGES IN
CONNECTION WITH THE
FURNISHING, USE, OR
PERFORMANCE OF THIS DOCUMENT
OR OF ANY INFORMATION
CONTAINED HEREIN. SHOULD
KEYSIGHT AND THE USER HAVE A
SEPARATE WRITTEN AGREEMENT
WITH WARRANTY TERMS COVERING
THE MATERIAL IN THIS DOCUMENT
THAT CONFLICT WITH THESE TERMS,
THE WARRANTY TERMS IN THE
SEPARATE AGREEMENT SHALL
CONTROL.
Safety Information
CAUTION
A CAUTION notice denotes a hazard. It
calls attention to an operating
procedure, practice, or the like that, if
not correctly performed or adhered to,
could result in damage to the product
or loss of important data. Do not
proceed beyond a CAUTION notice
until the indicated conditions are fully
understood and met.
WARNING
A WARNING notice denotes a hazard. It
calls attention to an operating
procedure, practice, or the like that, if
not correctly performed or adhered to,
could result in personal injury or death.
Do not proceed beyond a WARNING
notice until the indicated conditions are
fully understood and met.
Keysight U2761A Service Guide
Safety Symbols
The following symbols on the instrument and in the documentation indicate
precautions which must be taken to maintain safe operation of the instrument.
Direct current (DC)
Equipment protected throughout by
double insulation or reinforced
insulation
Alternating current (AC)
Off (mains supply)
Both direct and alternating current
On (mains supply)
Three-phase alternating current
Caution, risk of electric shock
Earth (ground) terminal
Caution, risk of danger (refer to this
manual for specific Warning or Caution
information)
Protective earth (ground) terminal
Caution, hot surface
Frame or chassis (ground) terminal
Out position of a bi-stable push control
Equipotentiality
In position of a bi-stable push control
Keysight U2761A Service Guide
3
General Safety Information
The following general safety precautions must be observed during all phases of
operation 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. Keysight Technologies Inc.
assumes no liability for the customer’s failure to comply with these requirements.
WARNING
– Do not operate the product in an explosive atmosphere or in the presence
of flammable gases or fumes.
– Do not use the equipment if it does not operate properly. Have the
equipment inspected by qualified service personnal.
CAUTION
– Observe all markings on the instrument before connecting any wiring to
the instrument.
– Use the device with the cables provided.
– Repair or service that is not covered in this manual should only be
performed by qualified personnels.
4
Keysight U2761A Service Guide
Environment Conditions
This instrument is designed for indoor use and in the area with low condensation.
The table below shows the general environmental requirements for this
instrument.
CAUTION
Environment cond itions
Requirements
Operating temperature
0 °C to 50 °C
Operating humidity
20 to 85% RH noncondensing
Storage temperature
–20 °C to 70 °C
Storage humidity
5 to 90% RH noncondensing
The U2761A USB modular function/arbitrary waveform generator complies
with the following safety and EMC requirements.
– IEC 61010-1:2001/EN61010-1:2001 (2nd Edition)
– Canada: CAN/CSA-C22.2 No. 61010-1-04
– IEC 61326-2002/EN 61326:1997+A1:1998+A2:2001+A3:2003
– Canada: ICES-001:2004
– Australia/New Zealand: AS/NZS CISPR11:2004
– USA: ANSI/UL 61010-1:2004
Keysight U2761A Service Guide
5
Regulatory Markings
The CE mark is a registered trademark
of the European Community. This CE
mark shows that the product complies
with all the relevant European Legal
Directives.
The RCM mark is a registered
trademark of the Australian
Communications and Media Authority.
ICES/NMB-001 indicates that this ISM
device complies with the
Canadian ICES-001.
Cet appareil ISM est conforme a la
norme NMB-001 du Canada.
This instrument complies with the
WEEE Directive (2002/96/EC) marking
requirement. This affixed product label
indicates that you must not discard
this electrical or electronic product in
domestic household waste.
The CSA mark is a registered
trademark of the Canadian
Standards Association.
6
Keysight U2761A Service Guide
Waste Electrical and Electronic Equipment (WEEE) Directive 2002/
96/EC
This instrument complies with the WEEE Directive (2002/96/EC) marking
requirement. This affixed product label indicates that you must not discard this
electrical or electronic product in domestic household waste.
Product category:
With reference to the equipment types in the WEEE directive Annex 1, this
instrument is classified as a “Monitoring and Control Instrument” product.
The affixed product label is as shown below.
Do not dispose in domestic household waste.
To return this unwanted instrument, contact your nearest Keysight Service Center,
or visit http://about.keysight.com/en/companyinfo/environment/takeback.shtml
for more information.
Sales and Technical Support
To contact Keysight for sales and technical support, refer to the support links on
the following Keysight websites:
– www.keysight.com/find/U2761A
(product-specific information and support, software and
documentation updates)
– www.keysight.com/find/assist
(worldwide contact information for repair and service)
Keysight U2761A Service Guide
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Keysight U2761A Service Guide
Table of Contents
Safety Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
General Safety Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Environment Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Regulatory Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Waste Electrical and Electronic Equipment (WEEE) Directive
2002/96/EC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Product category:
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Sales and Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1
Characteristics and Specifications
2
Getting Started
Introduction
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Self-Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Keysight Technologies Calibration Services . . . . . . . . . . . . . . . . . . .20
Calibration Interval
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
Types of Service Available . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
Extended Service Contracts
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
Obtaining Repair Service (Worldwide) . . . . . . . . . . . . . . . . . . . . . . .21
Repackaging for Shipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
3
Calibration
Introduction
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Recommended Test Equipment
. . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Test Consideration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Performance Verification Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Internal Timebase Verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Output Impedance Verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
DC Offset (High Impedance) Verification . . . . . . . . . . . . . . . . . . . . .28
AC Amplitude (High Impedance) Verification . . . . . . . . . . . . . . . . . .29
Amplitude Flatness (–20 dB Range) Verification
. . . . . . . . . . . . . . .31
Keysight U2761A Service Guide
9
Amplitude Flatness (0 dB Range) Verification . . . . . . . . . . . . . . . . . 34
Amplitude Flatness (+20 dB Range) Verification . . . . . . . . . . . . . . . 36
Calibration Procedure
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Internal Timebase Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Output Impedance Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
DC Offset (High Impedance) Adjustment . . . . . . . . . . . . . . . . . . . . . 41
AC Amplitude (High Impedance) Adjustment . . . . . . . . . . . . . . . . . . 42
Amplitude Flatness (–20 dB Range) Adjustment . . . . . . . . . . . . . . . 45
Amplitude Flatness (0 dB Range) Adjustment . . . . . . . . . . . . . . . . . 47
Amplitude Flatness (+20 dB Range) Adjustment . . . . . . . . . . . . . . . 49
4
Disassembly
General Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Disassembly Instructions
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Reassembly Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
5
Troubleshooting
Troubleshooting
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Index
10
Keysight U2761A Service Guide
List of Figures
Figure 3-1
Figure 3-2
Figure 3-3
Figure 3-4
Figure 3-5
Keysight U2761A Service Guide
U2761A to frequency counter connection . . . . . . . . . .26
U2761A to DMM four-wire connection . . . . . . . . . . . .27
U2761A to DMM connection . . . . . . . . . . . . . . . . . . . .28
U2761A to power meter connection . . . . . . . . . . . . . .31
U2761A to DMM four-wire connection . . . . . . . . . . . .40
11
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Keysight U2761A Service Guide
List of Tables
Table 3-1
Table 3-2
Table 3-3
Table 3-4
Table 3-5
Table 3-6
Table 3-7
Table 3-8
Table 3-9
Table 3-10
Table 3-11
Table 3-12
Table 3-13
Table 3-14
Table 3-15
Table 3-16
Table 3-17
Table 3-18
Table 3-19
Keysight U2761A Service Guide
Recommended test equipment . . . . . . . . . . . . . . . . . .24
Configuration for timebase verification . . . . . . . . . . . .27
Output impedance verification configuration . . . . . . .28
Configuration for DC offset verification . . . . . . . . . . . .29
Configuration for AC amplitude verification
. . . . . . . .30
AC amplitude verification worksheet . . . . . . . . . . . . . .31
Configuration for AC amplitude flatness
(–20 dB range) verification . . . . . . . . . . . . . . . . . . .33
Configuration for AC amplitude flatness (0 dB range)
verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
Configuration for AC amplitude flatness
(+20 dB range) verification . . . . . . . . . . . . . . . . . . .37
Timebase adjustment configuration
. . . . . . . . . . . . . .39
Output impedance adjustment configuration . . . . . . .40
DC offset (High Impedance) adjustment
configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
Configuration for Sine wave AC amplitude
adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
Sine wave flatness worksheet . . . . . . . . . . . . . . . . . . .43
Configuration for 50% ramp AC amplitude
adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Configuration for 50% pulse AC amplitude
adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
Configuration for AC amplitude flatness
(–20 dB range) adjustment . . . . . . . . . . . . . . . . . . .46
Configuration for AC amplitude flatness
(0 dB range) adjustment . . . . . . . . . . . . . . . . . . . . .48
Configuration for AC amplitude flatness
(+20 dB range) adjustment . . . . . . . . . . . . . . . . . . .50
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Keysight U2761A Service Guide
Keysight U2761A USB Modular Function/
Arbitrary Waveform Generator
Service Guide
1
Characteristics and
Specifications
For the characteristics and specifications of the U2761A USB Modular Function/
Arbitrary Waveform Generator, refer to the datasheet at
http://literature.cdn.keysight.com/litweb/pdf/5991-0413EN.pdf.
15
1
Characteristics and Specifications
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Keysight U2761A Service Guide
Keysight U2761A USB Modular Function/
Arbitrary Waveform Generator
Service Guide
2
Getting Started
Introduction
18
This chapter provides the self-test procedure for the U2761A USB modular
function generator. It also provides the information for returning your U2761A to
Keysight for calibration or servicing.
If you have a defective module, you can return it to Keysight for repair or
replacement.
17
2
Getting Started
Introduction
Self-Test
A brief power-on self-test occurs automatically whenever the U2761A is turned
on. This limited test assures that the instrument is capable of operation. To
perform a complete self-test, send the following SCPI command to the U2761A.
*TST?
The U2761A will automatically perform the complete self-test procedure when
the SCPI command is sent. The self-test will be completed in a few seconds.
– If the self-test is successful, a zero (0) is returned.
– If the self-test fails, an error number is returned.
Keysight Measurement Manager
To start the self-test procedure using the Keysight Measurement Manager,
perform the following test.
1 Click Tools > Sel f-Test.
18
Keysight U2761A Service Guide
Getting Started
2
2 Click Start on the Self-Test form.
3 Click OK to continue when the message box appears.
4 Wait for a few minutes for the self-test to complete.
5 The result is displayed on the form once the self-test has completed.
Keysight U2761A Service Guide
19
2
Getting Started
Keysight Technologies Calibration Services
When your U2761A is due for calibration, contact your local Keysight Service
Center for a low-cost recalibration. The U2761A is supported on automated
calibration systems, which allows Keysight to provide this service at a competitive
price.
Calibration Interval
The U2761A should be verified and calibrated on a regular interval based on the
measurement accuracy requirements of your application. A one-year interval is
adequate for most applications. Accuracy specifications are warranted only if
adjustments are made at regular verification and calibration intervals.
Types of Service Available
If your U2761A fails during the warranty period, Keysight will repair or replace it
under the terms of your warranty. After your warranty expires, Keysight offers
repair services at competitive prices.
Extended Service Contracts
Most Keysight products are provided with optional service contracts that extend
the coverage period after the standard warranty expires. If you have this service
contract and your U2761A happens to fail during the coverage period, Keysight
will repair or replace it according to the contract.
20
Keysight U2761A Service Guide
Getting Started
2
Obtaining Repair Service (Worldwide)
To obtain service for your U2761A (in-warranty, under service contract, or
post-warranty), contact your nearest Keysight Service Center. They will arrange to
have your unit repaired or replaced, and are able to provide warranty or repair cost
information where applicable.
To obtain warranty, service, or technical support information you can contact
Keysight at one of the following telephone numbers.
In the United States: 800 829 4444
In Europe: 31 20 547 2111
In Japan: (81) 426 56 7832
You can also use our Web link for the information on contacting Keysight
worldwide:
www.keysight.com/find/assist
Or contact your Keysight representative.
Before shipping your U2761A, ensure that you acquire shipping instructions,
including the components to be shipped, from the Keysight Service Center.
Keysight recommends that you retain the original shipping carton for use in such
shipments.
Keysight U2761A Service Guide
21
2
Getting Started
Repackaging for Shipment
If the U2761A is to be shipped to Keysight for service or repair, make sure that you
do the following.
– Attach a tag to the U2761A identifying the owner and indicating the required
service or repair. Include the model number and full serial number.
– Place the U2761A in its original container with appropriate packaging material
for shipping.
– Secure the container with strong tape or metal bands.
– If the original shipping container is not available, place your U2761A in a
container with at least four inches of compressible packaging material around
all sides of the U2761A. Use static-free packaging materials to avoid
additional damage to your U2761A.
NOTE
Keysight suggests that you always insure your shipments.
Cleaning
Clean the outer area of the U2761A with a soft, lint-free, and slightly dampened
cloth. Do not use detergent. Disassembly is not required for cleaning.
22
Keysight U2761A Service Guide
Keysight U2761A USB Modular Function/
Arbitrary Waveform Generator
Service Guide
3
Calibration
Introduction 24
Performance Verification Procedures
Calibration Procedure 38
26
The verification and calibration procedures described in this chapter verify that
the U2761A is operating normally and is within its warranted specifications.
23
3
Calibration
Introduction
If the U2761A fails any of the tests or if any abnormal test results are obtained,
return the unit to the Keysight Service Center for readjustment.
Recommended Test Equipment
The recommended test equipment for the verification and calibration procedures
are listed in the table below.
Table 3-1
Recommended test equipment
Instrument
Minimum requirement
Recommended model
Purpose
Digital
multimeter
(DMM)
AC volts
– True rms
– AC coupled
– Accuracy: ±0.02% to 1 MHz
Keysight 3458A
Measures voltage. Used in
multiple procedures
DC volts
– Accuracy: 50 ppm
– Resolution: 100 μV
Resistance
– 4-wire measurement
– Offset compensated
– Accuracy: ±0.1 Ω
Keysight E4418B
Measures voltage. Used in
multiple procedures
Power meter
–
–
–
–
Power sensor
– 100 kHz to 100 MHz
– 1 μW to 100 mW (–30 dBm to +20 dBm)
Keysight 8482A
Measure voltages. Used in
multiple procedures
Frequency
counter
– Accuracy: 0.1 ppm
Keysight 53131A Opt 010
Checks timebase parameter
Oscilloscope
– 500 MHz
– 2 GSa/s
– 50 Ω input termination
Keysight DS08064A
Checks output signal
24
100 kHz to 100 MHz
1 μW to 100 mW (–30 dBm to +20 dBm)
Accuracy: 0.02 dB
Resolution: 0.01 dB
Keysight U2761A Service Guide
Calibration
Table 3-1
3
Recommended test equipment (continued)
Instrument
Minimum requirement
Recommended model
Purpose
Spectrum
analyzer
–
–
–
–
10 kHz to 1 GHz
Average Continuous Power: +25 dBm
Amplitude Accuracy: ±0.5 dB
Input Impedance: 50 Ω
Keysight E4443A
Checks output signal
Cable and
adaptor
–
–
–
–
50 Ω BNC (male to male) cable
BNC (female) to dual banana
BNC (female) to N type (male)
BNC (female) to N type (female)
–
Signal interconnected
Test Consideration
For optimum performance, all procedures should comply with the following
recommendations.
– Ensure that the calibration ambient temperature is stable and between
23 °C ± 3 °C.
– The ambient relative humidity must be less than 80%.
– Allow a one-hour warm-up period before verification or adjustment.
– Keep the measurement cables as short as possible and consistent with the
impedance requirement.
– Use RG-58 or equivalent 50 Ω cable.
Keysight U2761A Service Guide
25
3
Calibration
Performance Verification Procedures
It is recommended to carry out performance verification tests when you first
receive the U2761A. The performance verification test results should be compared
to the specifications of the U2761A. You should repeat the performance
verification tests at every calibration interval.
If the U2761A fails the performance verification tests, adjustment or repair is
required. Some of the specifications are adjustable, or otherwise replacement of
parts may be required.
Internal Timebase Verification
This test verifies the accuracy of the output frequency of the U2761A. All output
frequencies are derived from a single generated frequency.
1 Connect the U2761A to a frequency counter as shown in the following figure.
The input termination of the frequency counter must be 50 Ω.
Figure 3-1
26
U2761A to frequency counter connection
Keysight U2761A Service Guide
Calibration
3
2 Set the U2761A to the output shown in the table below and measure the
output frequency. Make sure that the U2761A output is enabled.
Table 3-2
Configuration for timebase verification
U2761A
Measurement
Function
Amplitude
Frequency
Nominal
Error[a]
Sine
1.00 Vpp
10.0000 MHz
10.0000 MHz
±80 Hz
[a] Based upon ±8 ppm for one year.
3 Compare the measured frequency with the test limit shown in Table 3-2.
Output Impedance Verification
The U2761A stores the calibration constant for the output impedance. The output
impedance measurement is necessary to calculate the correct output amplitude
when the load impedance is not at High-Z termination. The output impedance is
measured at three different output paths.
1 Set the DMM to measure offset-compensated, four-wire ohms. Set the DMM
to use 100 NPLC integration. Connect the DMM to the U2761A as shown in
the figure below.
Figure 3-2
Keysight U2761A Service Guide
U2761A to DMM four-wire connection
27
3
Calibration
2 Use the DMM to make the resistance measurement at the output terminal for
each setup shown in the table below. The expected measured value is
approximately 50 Ω.
3 This procedure will require you to unsecure the instrument for calibration. See
“Calibration Procedure” on page 38 for more information on how to unsecure
the instrument for calibration. The calibration constant is not stored to the
U2761A after completing the setup.
Table 3-3
Output impedance verification configuration
U2761A
DMM
CalSet
Output path
Lower margin
Measurement
Upper margin
5
–20 dB
49.5 Ω
Ω
50.5 Ω
6
0 dB
49.5 Ω
Ω
50.5 Ω
7
+20 dB
49.5 Ω
Ω
50.5 Ω
4 Exit the Calibration Mode.
DC Offset (High Impedance) Verification
This procedure verifies the accuracy of the DC offset with high impedance load
(DMM input impedance of 10 MΩ).
1 Set the DMM to measure DC voltage. Connect the DMM to the U2761A as
shown in the following figure. The DMM input impedance must be set to
10 MΩ.
Figure 3-3
28
U2761A to DMM connection
Keysight U2761A Service Guide
Calibration
3
2 Set the U2761A based on the following.
– Load impedance: High-Z
– Function: DC
3 Set the U2761A to each output listed in the table below.
Table 3-4
Configuration for DC offset verification
U2761A
Measurement
DC offset
Nominal
Error[a]
–5.000 VDC
–5.000 VDC
±0.11 VDC
–2.500 VDC
–2.500 VDC
±0.06 VDC
0.000 VDC
0.000 VDC
±0.01 VDC
+2.500 VDC
+2.500 VDC
±0.06 VDC
+5.000 VDC
+5.000 VDC
±0.11 VDC
[a] Based upon ±2% of offset setting ±10 mV (High-Z).
4 Compare the measured voltages with the test limits shown in Table 3-4.
AC Amplitude (High Impedance) Verification
This procedure verifies the accuracy of the AC output amplitude at frequencies of
1 kHz and 100 kHz, and establishes reference measurement for the higher
frequency flatness verification procedures.
1 Set the DMM to measure AC voltage. Connect the DMM to the U2761A as
shown in Figure 3-3.
2 Set the U2761A based on the following.
– Load impedance: High-Z
– Offset: 0 V
3 Set the U2761A to each output listed in the table below.
Keysight U2761A Service Guide
29
3
Calibration
Table 3-5
Configuration for AC amplitude verification
U2761A
Measurement
Function
Frequency
Amplitude
Nominal
Error[a]
Sine
1.00000 kHz
70 mVrms
70 mVrms
±4.236 mVrms
Sine
100.000 kHz
70 mVrms
70 mVrms
±5.146 mVrms
Sine
1.00000 kHz
700 mVrms
700 mVrms
±10.54 mVrms
Sine
100.000 kHz
700 mVrms
700 mVrms
±19.64 mVrms
Sine
1.00000 kHz
3.500 Vrms
3.500 Vrms
±38.54 mVrms
Sine
100.000 kHz
3.500 Vrms
3.500 Vrms
±84.04 mVrms
50% Ramp
1.00000 kHz
50 mVrms
50 mVrms
±3.387 Vrms
50% Ramp
1.00000 kHz
500 mVrms
500 mVrms
±7.887 mVrms
50% Ramp
1.00000 kHz
2.500 Vrms
2.500 Vrms
±27.89 mVrms
50% Square
1.00000 kHz
90 mVrms
90 mVrms
±5.900 mVrms
50% Square
1.00000 kHz
900 mVrms
900 mVrms
±14.00 mVrms
50% Square
1.00000 kHz
4.500 VRms
4.500 Vrms
±50.00 mVrms
[a] 1 kHz: Based upon ±1% of setting ±5 mVpp (50 Ω) converted to Vrms for High-Z.
100 kHz: Based upon ±0.2 dB (2.3%) of setting ±5 mVpp (50 Ω) converted to Vrms for High-Z.
4 Compare the measured voltage with the test limits shown in above table, and
fill in Table 3-6 using the following equation.
V rm s100kHz
Offset = 20 × log 
 V rm s1kHz 
30
Keysight U2761A Service Guide
Calibration
Table 3-6
3
AC amplitude verification worksheet
U2761A
DMM
Calculation
Measurement
Offset
Function
Frequency
Amplitude
Sine
1.00000 kHz
70 mVrms
Vrms
Sine
100.000 kHz
70 mVrms
Vrms
Sine
1.00000 kHz
700 mVrms
Vrms
Sine
100.000 kHz
700 mVrms
Vrms
Sine
1.00000 kHz
3.500 Vrms
Vrms
Sine
100.000 kHz
3.500 Vrms
Vrms
Offset –20 dB = ___ dB
Offset 0 dB = ___ dB
Offset + 20 dB = ___ dB
Amplitude Flatness (–20 dB Range) Verification
This procedure verifies the high frequency AC amplitude flatness above 100 kHz
on the –20 dB attenuator range relative to 1 kHz.
1 Connect the power meter to measure the output amplitude of the U2761A as
shown in the figure below.
Figure 3-4
Keysight U2761A Service Guide
U2761A to power meter connection
31
3
Calibration
2 Set the U2761A based on the following.
– Load impedance: 50 Ω
– Function: Sine wave
– Frequency: 100 kHz
– Amplitude: 35 mVrms (–16.108 dBm)
3 Set the power meter Filter Mode to Manual and set Average Length to 500 to
improve measurement stability. Allow a minimum of 30 s between the time of
setting the U2761A and collecting the measurement reading.
4 On the power meter, use the Relative Power function to set the current
reading as the reference value. This allows you to compare future
measurement result in dB.
5 Set the power meter Offset to the Offset–20dB value previously calculated in
Table 3-6. The power meter will directly read the flatness error specification to
1 kHz.
6 Set the U2761A to each output listed in Table 3-7. Measure the output
amplitude using the power meter (the relative measurement in dB).
7 Compare the measured output with the test limits shown in Table 3-7.
32
Keysight U2761A Service Guide
Calibration
Table 3-7
3
Configuration for AC amplitude flatness (–20 dB range) verification
U2761A
Measurement
Function
Amplitude
Frequency
Nominal
Error
Sine
35 mVrms
100.000 kHz
0.000 dB
±0.2 dB
Sine
35 mVrms
160.000 kHz
0.000 dB
±0.35 dB
Sine
35 mVrms
250.000 kHz
0.000 dB
±0.35 dB
Sine
35 mVrms
400.000 kHz
0.000 dB
±0.35 dB
Sine
35 mVrms
630.000 kHz
0.000 dB
±0.35 dB
Sine
35 mVrms
1.00000 MHz
0.000 dB
±0.35 dB
Sine
35 mVrms
1.60000 MHz
0.000 dB
±0.7 dB
Sine
35 mVrms
2.50000 MHz
0.000 dB
±0.7 dB
Sine
35 mVrms
4.00000 MHz
0.000 dB
±0.7 dB
Sine
35 mVrms
6.30000 MHz
0.000 dB
±0.7 dB
Sine
35 mVrms
10.0000 MHz
0.000 dB
±0.7 dB
Sine
35 mVrms
11.5000 MHz
0.000 dB
±0.7 dB
Sine
35 mVrms
13.2000 MHz
0.000 dB
±0.7 dB
Sine
35 mVrms
15.2000 MHz
0.000 dB
±0.7 dB
Sine
35 mVrms
17.4000 MHz
0.000 dB
±0.7 dB
Sine
35 mVrms
20.0000 MHz
0.000 dB
±0.7 dB
Keysight U2761A Service Guide
33
3
Calibration
Amplitude Flatness (0 dB Range) Verification
This procedure verifies the high frequency AC amplitude flatness above 100 kHz
on the 0 dB range relative to 1 kHz.
1 Connect the power meter to measure the output amplitude of the U2761A as
shown in Figure 3-4.
2 Set the U2761A based on the following.
– Load impedance: 50 Ω
– Function: Sine wave
– Frequency: 100 kHz
– Amplitude: 350 mVrms (+3.892 dBm)
3 Set the power meter Filter Mode to Auto if you have previously set it to
Manual.
4 On the power meter, use the Relative Power function to set the current
reading as the reference value. This will allow you to compare future
measurement result in dB.
5 Set the power meter Offset to Offset0dB value previously calculated in
Table 3-6. The power meter will directly read the flatness error specification
relative to 1 kHz.
6 Set the U2761A to each output listed in the Table 3-8. Measure the output
amplitude using the power meter (the relative measurement in dB).
7 Compare the measured output with the test limits shown in the Table 3-8.
34
Keysight U2761A Service Guide
Calibration
Table 3-8
3
Configuration for AC amplitude flatness (0 dB range) verification
U2761A
Measurement
Function
Amplitude
Frequency
Nominal
Error
Sine
350 mVrms
100.000 kHz
0.000 dB
±0.2 dB
Sine
350 mVrms
160.000 kHz
0.000 dB
±0.35 dB
Sine
350 mVrms
250.000 kHz
0.000 dB
±0.35 dB
Sine
350 mVrms
400.000 kHz
0.000 dB
±0.35 dB
Sine
350 mVrms
630.000 kHz
0.000 dB
±0.35 dB
Sine
350 mVrms
1.00000 MHz
0.000 dB
±0.35 dB
Sine
350 mVrms
1.60000 MHz
0.000 dB
±0.7 dB
Sine
350 mVrms
2.50000 MHz
0.000 dB
±0.7 dB
Sine
350 mVrms
4.00000 MHz
0.000 dB
±0.7 dB
Sine
350 mVrms
6.30000 MHz
0.000 dB
±0.7 dB
Sine
350 mVrms
10.0000 MHz
0.000 dB
±0.7 dB
Sine
350 mVrms
11.5000 MHz
0.000 dB
±0.7 dB
Sine
350 mVrms
13.2000 MHz
0.000 dB
±0.7 dB
Sine
350 mVrms
15.2000 MHz
0.000 dB
±0.7 dB
Sine
350 mVrms
17.4000 MHz
0.000 dB
±0.7 dB
Sine
350 mVrms
20.0000 MHz
0.000 dB
±0.7 dB
Keysight U2761A Service Guide
35
3
Calibration
Amplitude Flatness (+20 dB Range) Verification
This procedure verifies the high frequency AC amplitude flatness above 100 kHz
on the +20 dB amplifier range relative to 1 kHz.
1 Connect the power meter and power sensor together to measure the output
amplitude of the U2761A as shown in Figure 3-4.
2 Set the U2761A based on the following.
– Load impedance: 50 Ω
– Function: Sine wave
– Frequency: 100 kHz
– Amplitude: 1.750 Vrms (+17.871 dBm)
3 Set the power meter Filter Mode to Auto if you have previously set it to
Manual.
4 On the power meter, use the Relative Power function to set the current
reading as the reference value. This will allow you to compare future
measurement result in dB.
5 Set the power meter Offset to Offset+20dB value previously calculated in
Table 3-6. The power meter will directly read the flatness error specification
relative to 1 kHz.
6 Set the U2761A to each output listed in the Table 3-9. Measure the output
amplitude using the power meter (the relative measurement in dB).
7 Compare the measured output with the test limits shown in the Table 3-9.
36
Keysight U2761A Service Guide
Calibration
Table 3-9
3
Configuration for AC amplitude flatness (+20 dB range) verification
U2761A
Measurement
Function
Amplitude
Frequency
Nominal
Error
Sine
1.750 Vrms
100.000 kHz
0.000 dB
±0.2 dB
Sine
1.750 Vrms
160.000 kHz
0.000 dB
±0.35 dB
Sine
1.750 Vrms
250.000 kHz
0.000 dB
±0.35 dB
Sine
1.750 Vrms
400.000 kHz
0.000 dB
±0.35 dB
Sine
1.750 Vrms
630.000 kHz
0.000 dB
±0.35 dB
Sine
1.750 Vrms
1.00000 MHz
0.000 dB
±0.35 dB
Sine
1.750 Vrms
1.60000 MHz
0.000 dB
±0.7 dB
Sine
1.750 Vrms
2.50000 MHz
0.000 dB
±0.7 dB
Sine
1.750 Vrms
4.00000 MHz
0.000 dB
±0.7 dB
Sine
1.750 Vrms
6.30000 MHz
0.000 dB
±0.7 dB
Sine
1.750 Vrms
10.0000 MHz
0.000 dB
±0.7 dB
Sine
1.750 Vrms
11.5000 MHz
0.000 dB
±0.7 dB
Sine
1.750 Vrms
13.2000 MHz
0.000 dB
±0.7 dB
Sine
1.750 Vrms
15.2000 MHz
0.000 dB
±0.7 dB
Sine
1.750 Vrms
17.4000 MHz
0.000 dB
±0.7 dB
Sine
1.750 Vrms
20.0000 MHz
0.000 dB
±0.7 dB
Keysight U2761A Service Guide
37
3
Calibration
Calibration Procedure
Calibration is necessary when the one-year calibration interval has expired, or
whenever the U2761A fails any verification test. To enter the calibration mode,
send the following SCPI command to the U2761A.
CALibration:SECure:STATe OFF,U2761A
Once the calibration state is unsecured, the U2761A is now in the calibration
mode and setup is 0 by default. All the calibration setup is predetermined and
transparent to the user. The user is free to perform a full calibration setup from
1 to 115, or may choose to perform only a particular group. To perform a
particular calibration setup, send the following SCPI command to U2761A.
CALibration:SETup<1|2|3|...|115>
The current calibration setup can be queried using the following SCPI command
when necessary.
CALibration:SETup?
The U2761A will output a predefined waveform at the output terminal according
to the setup number entered. Perform the measurements as described in “Internal
Timebase Adjustment” on page 39 until “Amplitude Flatness (+20 dB Range)
Adjustment” on page 49, and enter the measured values to the U2761A using the
SCPI commands as follows.
CALibration:VALue <value>
The calibration value must be entered at the magnitude of the units shown in the
configuration tables accordingly. If the user accidentally enters a wrong value,
simply reenter a correct value under the same calibration setup. Proceed to the
next calibration setup by entering a new setup number once the calibration value
is entered.
Please note that the calibration constant will only be stored after the user
completes the subsequent calibration setup in each group within a single
calibration mode login. To exit the calibration mode, send the following SCPI
command to the U2761A.
CALibration:SECure:STATe ON,U2761A
38
Keysight U2761A Service Guide
Calibration
3
Internal Timebase Adjustment
The U2761A relies on a VCTCXO to generate the precision clock to drive the DDS
architecture. This procedure determines the suitable control voltage for the
VCTCXO to output the correct frequency. This procedure implements a three-time
approach to obtain the best possible control voltage.
1 Set the frequency counter to measure frequency. The frequency counter
resolution must be higher than 0.1 ppm (eight digits or more).
2 Set the frequency counter input termination to 50 Ω. If your frequency counter
does not have a 50 Ω input termination, you must provide an external
termination.
3 Connect the frequency counter as shown in Figure 3-1. Use the frequency
counter to measure the output frequency for each setup shown in the table
below.
4 Enter the measured value to the U2761A as described in “Calibration
Procedure” on page 38.
Table 3-10
Timebase adjustment configuration
U2761A
Frequency counter
Setup
Frequency
Amplitude
Lower margin
Measurement
Upper margin
1
< 10 MHz
1 Vpp
9.999000 MHz
MHz
9.999800 MHz
2
> 10 MHz
1 Vpp
10.000200 MHz
MHz
10.001000 MHz
3
≈ 10 MHz
1 Vpp
9.999900 MHz
MHz
10.000100 MHz
4[a]
= 10 MHz
1 Vpp
9.999990 MHz
MHz
10.000010 MHz
[a] Calibration constant is stored after completing this setup.
5 Proceed to output impedance adjustment or exit the calibration mode when
necessary.
Keysight U2761A Service Guide
39
3
Calibration
Output Impedance Adjustment
The U2761A stores the calibration constant for output impedance. The output
impedance measurement is necessary to calculate the correct output amplitude
when the load impedance is not at High-Z termination. The output impedance is
measured at three different output paths.
1 Set the DMM to measure offset-compensated, four-wire ohms. Set the DMM
to use 100 NPLC integration. Connect the DMM to the U2761A as shown in
the figure below.
Figure 3-5
U2761A to DMM four-wire connection
2 Use the DMM to make the resistance measurement at the output terminal for
each setup shown in the table below. The expected measured value is
approximately 50 Ω.
3 Make sure the Offset Compensation setting in the DMM is switched on.
4 Enter the measured value to the U2761A as described in “Calibration
Procedure” on page 38.
Table 3-11
Output impedance adjustment configuration
U2761A
DMM
Setup
Output path
Lower margin
Measurement
Upper margin
5
–20 dB
49.5 Ω
Ω
50.5 Ω
6
0 dB
49.5 Ω
Ω
50.5 Ω
7[a]
+20 dB
49.5 Ω
Ω
50.5 Ω
[a] Calibration constant is stored after completing this setup.
40
Keysight U2761A Service Guide
Calibration
3
5 Proceed to DC offset adjustment or exit the calibration mode when necessary.
DC Offset (High Impedance) Adjustment
The U2761A stores the calibration constant related to gain and offset of the
internal system DAC to control the offset setting. This setting is used for both
offset and DC outputs.
1 Set the DMM to measure DC voltage. Connect the DMM to the U2761A as
shown in Figure 3-3. The DMM input impedance should be set to 10 MΩ.
2 Use the DMM to perform the DC voltage measurement at the output terminal
for each setup shown in the table below.
3 Enter the measured value to the U2761A as described in “Calibration
Procedure” on page 38.
Table 3-12
DC offset (High Impedance) adjustment configuration
U2761A
DMM
Setup
Amplifier
DC offset
Lower margin
Measurement
Upper margin
8
Off
+4.800 VDC
+4.608 VDC
VDC
+4.992 VDC
9
Off
–4.800 VDC
–4.992 VDC
VDC
–4.608 VDC
10
On
+2.600 VDC
+2.496 VDC
VDC
+2.704 VDC
11
On
+4.800 VDC
+4.608 VDC
VDC
+4.992 VDC
12
On
–2.600 VDC
–2.704 VDC
VDC
–2.496 VDC
13[a]
On
–4.800 VDC
–4.992 VDC
VDC
–4.608 VDC
[a] Calibration constant is stored after completing this setup.
4 Proceed to AC amplitude (High Impedance) adjustment or exit the calibration
mode when necessary.
Keysight U2761A Service Guide
41
3
Calibration
AC Amplitude (High Impedance) Adjustment
This procedure calculates the AC amplitude calibration factor of three output
paths for Sine wave, Ramp wave, and Square wave individually.
1 Set the DMM to measure AC voltage. Connect the DMM to the U2761A as
shown in Figure 3-3.
2 Use the DMM to perform AC voltage measurement at the output terminal for
each setup shown in the table below.
3 Enter the measured value to the U2761A as described in “Calibration
Procedure” on page 38.
Table 3-13
Configuration for Sine wave AC amplitude adjustment
U2761A
DMM
Setup
Function
Frequency
Amplitude
Lower margin
Measurement
Upper margin
14
Sine
1.00000 kHz
32 mVrms
30.4 mVrms
Vrms
33.6 mVrms
15
Sine
1.00000 kHz
60 mVrms
57.0 mVrms
Vrms
63.0 mVrms
16
Sine
100.000 kHz
60 mVms
57.0 mVrms
Vrms
63.0 mVrms
17
Sine
1.00000 kHz
80 mVrms
74.4 mVrms
Vrms
85.6 mVrms
18
Sine
1.00000 kHz
600 mVrms
558 mVrms
Vrms
642 mVrms
19
Sine
100.000 kHz
600 mVrms
558 mVrms
Vrms
642 mVrms
20
Sine
1.00000 kHz
800 mVrms
744 mVrms
Vrms
856 mVrms
21
Sine
1.00000 kHz
3.000 Vrms
2.79 Vrms
Vrms
3.21 Vrms
22
Sine
100.000 kHz
800 mVrms
744 mVrms
Vrms
856 mVrms
4 Fill in the table below using the measurement results in Table 3-13.
42
Keysight U2761A Service Guide
Calibration
Table 3-14
3
Sine wave flatness worksheet
Parameter
Calculation
Offset
Offset–20dB
V
Offset = 20 × log ---value
---------(-16
---)
V value ( 15 )
dB
Offset0dB
V
Offset = 20 × log ---value
---------(-19
---)
V value ( 18 )
dB
Offset+20dB
V
Offset = 20 × log ---value
---------(-22
---)
V value ( 20 )
dB
5 Use the DMM to perform the AC voltage measurement at the output terminal
for each setup shown in the table below.
6 Enter the measured value to the U2761A as described in “Calibration
Procedure” on page 38.
Table 3-15
Configuration for 50% ramp AC amplitude adjustment
U2761A
DMM
Setup
Function
Frequency
Amplitude
Lower margin
23
50% Ramp
1.00000 kHz
28 mVrms
26.6 mVrms
Vrms
29.4 mVrms
24
50% Ramp
1.00000 kHz
50 mVrms
47.5 mVrms
Vrms
52.5 mVrms
25
50% Ramp
1.00000 kHz
70 mVrms
65.1 mVrms
Vrms
74.9 mVrms
26
50% Ramp
1.00000 kHz
500 mVrms
465 mVrms
Vrms
535 mVrms
27
50% Ramp
1.00000 kHz
700 mVrms
651 mVrms
Vrms
749 mVrms
28
50% Ramp
1.00000 kHz
2.500 Vrms
2.325 Vrms
Vrms
2.675 Vrms
Keysight U2761A Service Guide
Measurement
Upper margin
43
3
Calibration
7 Use the DMM to perform the AC voltage measurement at the output terminal
for each setup shown in the table below.
8 Enter the measured value to the U2761A as described in “Calibration
Procedure” on page 38.
Table 3-16
Configuration for 50% pulse AC amplitude adjustment
U2761A
DMM
Setup
Function
Period
Amplitude
Lower margin
Measurement
Upper margin
29
50% Pulse
1.00000 ms
44 mVrms
41.8 mVrms
Vrms
46.2 mVrms
30
50% Pulse
1.00000 ms
90 mVrms
85.5 mVrms
Vrms
94.5 mVrms
31
50% Pulse
1.00000 ms
110 mVrms
102.3 mVrms
Vrms
117.7 mVrms
32
50% Pulse
1.00000 ms
900 mVrms
837 mVrms
Vrms
963 mVrms
33
50% Pulse
1.00000 ms
1.100 Vrms
1.023 Vrms
Vrms
1.177 Vrms
34[a]
50% Pulse
1.00000 ms
4.500 Vrms
4.185 Vrms
Vrms
4.815 Vrms
[a] Calibration constant is stored after completing this setup.
9 Proceed to AC amplitude flatness (–20 dB range) adjustment or exit the
calibration mode when necessary.
44
Keysight U2761A Service Guide
Calibration
3
Amplitude Flatness (–20 dB Range) Adjustment
This procedure calibrates the AC amplitude flatness for high frequency using
–20 dB attenuator. This calibration is performed using Sine wave at nominal
amplitude of 30 mVrms across 50 Ω load.
1 Connect the power meter to measure the output amplitude of the U2761A as
shown in Figure 3-4.
2 Set the power meter Filter Mode to Manual and Averaging Length to 500, to
improve the measurement stability. Allow a minimum of 30 s between setting
time and collecting the measurement reading.
3 Use the power meter to perform a 100 kHz AC power measurement at the
output terminal for setup 35 shown in Table 3-17. Setup 35 establishes the
power reference for all the remaining setups in Table 3-17. You must always
perform setup 35 before any of the following setups.
4 On the power meter, use the Relative Power function to set the current
reading as the reference value. This will allow you to make future measurement
result in dB.
5 Set the power meter Offset to Offset–20dB value previously calculated in
Table 3-14. The power meter will directly read the flatness error specification
relative to 1 kHz.
6 Enter the measured value to the U2761A as described in “Calibration
Procedure” on page 38.
7 Proceed to AC amplitude flatness (0 dB range) adjustment or exit the
calibration mode when necessary.
Keysight U2761A Service Guide
45
3
Calibration
Table 3-17
Configuration for AC amplitude flatness (–20 dB range) adjustment
U2761A
Power meter
Setup
Function
Frequency
Lower margin
Measurement
Upper margin
35
Sine
100.000 kHz
–0.2 dB
(Offset–20dB)
+0.2 dB
dB
46
36
Sine
780.000 kHz
–1.4 dB
dB
+1.4 dB
37
Sine
1.56000 MHz
–1.4 dB
dB
+1.4 dB
38
Sine
2.34000 MHz
–1.4 dB
dB
+1.4 dB
39
Sine
3.13000 MHz
–1.4 dB
dB
+1.4 dB
40
Sine
3.91000 MHz
–1.4 dB
dB
+1.4 dB
41
Sine
4.69000 MHz
–1.4 dB
dB
+1.4 dB
42
Sine
5.47000 MHz
–1.4 dB
dB
+1.4 dB
43
Sine
6.25000 MHz
–1.4 dB
dB
+1.4 dB
44
Sine
7.03000 MHz
–1.4 dB
dB
+1.4 dB
45
Sine
7.81000 MHz
–1.4 dB
dB
+1.4 dB
46
Sine
8.59000 MHz
–1.4 dB
dB
+1.4 dB
47
Sine
9.38000 MHz
–1.4 dB
dB
+1.4 dB
48
Sine
10.1600 MHz
–1.4 dB
dB
+1.4 dB
49
Sine
10.9400 MHz
–1.4 dB
dB
+1.4 dB
50
Sine
11.7200 MHz
–1.4 dB
dB
+1.4 dB
51
Sine
12.5000 MHz
–1.4 dB
dB
+1.4 dB
52
Sine
13.2800 MHz
–1.4 dB
dB
+1.4 dB
53
Sine
14.0600 MHz
–1.4 dB
dB
+1.4 dB
54
Sine
14.8400 MHz
–1.4 dB
dB
+1.4 dB
55
Sine
15.6300 MHz
–1.4 dB
dB
+1.4 dB
56
Sine
16.4100 MHz
–1.4 dB
dB
+1.4 dB
Keysight U2761A Service Guide
Calibration
Table 3-17
3
Configuration for AC amplitude flatness (–20 dB range) adjustment (continued)
U2761A
Power meter
Setup
Function
Frequency
Lower margin
Measurement
Upper margin
57
Sine
17.1900 MHz
–1.4 dB
dB
+1.4dB
58
Sine
17.9700 MHz
–1.4 dB
dB
+1.4 dB
59
Sine
18.7500 MHz
–1.4 dB
dB
+1.4 dB
60
Sine
19.5300 MHz
–1.4 dB
dB
+1.4 dB
61[a]
Sine
20.0000 MHz
–1.4 dB
dB
+1.4 dB
[a] Calibration constant is stored after completing this setup.
Amplitude Flatness (0 dB Range) Adjustment
This procedure calibrates the AC amplitude flatness for high frequency using 0 dB
direct path. This calibration is performed using Sine wave at nominal amplitude of
300 mVrms across 50 Ω load.
1 Connect the power meter to measure the output amplitude of the U2761A as
shown in Figure 3-4.
2 Set the power meter Filter Mode to Auto if you have previously set it to Manual.
3 Use the power meter to perform a 100 kHz AC power measurement at the
output terminal for setup 62 shown in Table 3-18. Setup 62 establishes the
power reference for all remaining setups in Table 3-18. You must always
perform setup 62 before any of the following setups.
4 On the power meter, use the Relative Power function to set the current
reading as the reference value. This will allow you to make future measurement
result in dB.
5 Set the power meter Offset to Offset0dB value previously calculated in
Table 3-14. The power meter will directly read the flatness error specification
relative to 1 kHz.
6 Enter the measured value to the U2761A as described in “Calibration
Procedure” on page 38.
7 Proceed to AC amplitude flatness (+20 dB range) adjustment or exit the
calibration mode when necessary.
Keysight U2761A Service Guide
47
3
Calibration
Table 3-18
Configuration for AC amplitude flatness (0 dB range) adjustment
U2761A
Power meter
Setup
Function
Frequency
Lower margin
Measurement
62
Sine
100.000 kHz
–0.2 dB
(Offset0dB)
Upper margin
+0.2 dB
dB
48
63
Sine
780.000 kHz
–1.4 dB
dB
+1.4 dB
64
Sine
1.56000 MHz
–1.4 dB
dB
+1.4 dB
65
Sine
2.34000 MHz
–1.4 dB
dB
+1.4 dB
66
Sine
3.13000 MHz
–1.4 dB
dB
+1.4 dB
67
Sine
3.91000 MHz
–1.4 dB
dB
+1.4 dB
68
Sine
4.69000 MHz
–1.4 dB
dB
+1.4 dB
69
Sine
5.47000 MHz
–1.4 dB
dB
+1.4 dB
70
Sine
6.25000 MHz
–1.4 dB
dB
+1.4 dB
71
Sine
7.03000 MHz
–1.4 dB
dB
+1.4 dB
72
Sine
7.81000 MHz
–1.4 dB
dB
+1.4 dB
73
Sine
8.59000 MHz
–1.4 dB
dB
+1.4 dB
74
Sine
9.38000 MHz
–1.4 dB
dB
+1.4 dB
75
Sine
10.1600 MHz
–1.4 dB
dB
+1.4 dB
76
Sine
10.9400 MHz
–1.4 dB
dB
+1.4 dB
77
Sine
11.7200 MHz
–1.4 dB
dB
+1.4 dB
78
Sine
12.5000 MHz
–1.4 dB
dB
+1.4 dB
79
Sine
13.2800 MHz
–1.4 dB
dB
+1.4 dB
80
Sine
14.0600 MHz
–1.4 dB
dB
+1.4 dB
81
Sine
14.8400 MHz
–1.4 dB
dB
+1.4 dB
82
Sine
15.6300 MHz
–1.4 dB
dB
+1.4 dB
83
Sine
16.4100 MHz
–1.4 dB
dB
+1.4 dB
Keysight U2761A Service Guide
Calibration
Table 3-18
3
Configuration for AC amplitude flatness (0 dB range) adjustment (continued)
U2761A
Power meter
Setup
Function
Frequency
Lower margin
Measurement
Upper margin
84
Sine
17.1900 MHz
–1.4 dB
dB
+1.4 dB
85
Sine
17.9700 MHz
–1.4 dB
dB
+1.4 dB
86
Sine
18.7500 MHz
–1.4 dB
dB
+1.4 dB
87
Sine
19.5300 MHz
–1.4 dB
dB
+1.4 dB
88[a]
Sine
20.0000 MHz
–1.4 dB
dB
+1.4 dB
[a] Calibration constant is stored after completing this setup.
Amplitude Flatness (+20 dB Range) Adjustment
This procedure calibrates the AC amplitude flatness for high frequency using
+20 dB amplifier. This calibration is performed using Sine wave at nominal
amplitude of 400 mVrms across 50 Ω load.
1 Connect the power meter to measure the output amplitude of the U2761A as
shown in Figure 3-4.
2 Set the power meter Filter Mode to Auto if you have previously set it to Manual.
3 Use the power meter to perform a 100 kHz AC power measurement at the
output terminal for setup 89 in Table 3-19. Setup 89 establishes the power
reference for all the remaining setups in Table 3-19. You must always perform
setup 89 before any of the following setups.
4 On the power meter, use the Relative Power function to set the current
reading as the reference value. This will allow you to make future measurement
result in dB.
5 Set the power meter Offset to Offset+20dB value previously calculated in
Table 3-14. The power meter will directly read the flatness error specification
relative to 1 kHz.
6 Enter the measured value to the U2761A as described in “Calibration
Procedure” on page 38.
NOTE
This is the final adjustment procedure for the U2761A.
Keysight U2761A Service Guide
49
3
Calibration
Table 3-19
Configuration for AC amplitude flatness (+20 dB range) adjustment
U2761A
50
Power meter
Setup
Function
Frequency
Lower margin
Measurement
Upper margin
89
Sine
100.000 kHz
–0.2 dB
90
Sine
780.000 kHz
–1.4 dB
dB
+1.4 dB
91
Sine
1.56000 MHz
–1.4 dB
dB
+1.4 dB
92
Sine
2.34000 MHz
–1.4 dB
dB
+1.4 dB
93
Sine
3.13000 MHz
–1.4 dB
dB
+1.4 dB
94
Sine
3.91000 MHz
–1.4 dB
dB
+1.4 dB
95
Sine
4.69000 MHz
–1.4 dB
dB
+1.4 dB
96
Sine
5.47000 MHz
–1.4 dB
dB
+1.4 dB
97
Sine
6.25000 MHz
–1.4 dB
dB
+1.4 dB
98
Sine
7.03000 MHz
–1.4 dB
dB
+1.4 dB
99
Sine
7.81000 MHz
–1.4 dB
dB
+1.4 dB
100
Sine
8.59000 MHz
–1.4 dB
dB
+1.4 dB
101
Sine
9.38000 MHz
–1.4 dB
dB
+1.4 dB
102
Sine
10.1600 MHz
–1.4 dB
dB
+1.4 dB
103
Sine
10.9400 MHz
–1.4 dB
dB
+1.4 dB
104
Sine
11.7200 MHz
–1.4 dB
dB
+1.4 dB
105
Sine
12.5000 MHz
–1.4 dB
dB
+1.4 dB
106
Sine
13.2800 MHz
–1.4 dB
dB
+1.4 dB
107
Sine
14.0600 MHz
–1.4 dB
dB
+1.4 dB
108
Sine
14.8400 MHz
–1.4 dB
dB
+1.4 dB
109
Sine
15.6300 MHz
–1.4 dB
dB
+1.4 dB
110
Sine
16.4100 MHz
–1.4 dB
dB
+1.4 dB
(Offset+20dB)
dB
+0.2 dB
Keysight U2761A Service Guide
Calibration
Table 3-19
3
Configuration for AC amplitude flatness (+20 dB range) adjustment (continued)
U2761A
Power meter
Setup
Function
Frequency
Lower margin
Measurement
Upper margin
111
Sine
17.1900 MHz
–1.4 dB
dB
+1.4 dB
112
Sine
17.9700 MHz
–1.4 dB
dB
+1.4 dB
113
Sine
18.7500 MHz
–1.4 dB
dB
+1.4 dB
114
Sine
19.5300 MHz
–1.4 dB
dB
+1.4 dB
115[a]
Sine
20.0000 MHz
–1.4 dB
dB
+1.4 dB
[a] Calibration constant is stored after completing this setup.
Keysight U2761A Service Guide
51
3
Calibration
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52
Keysight U2761A Service Guide
Keysight U2761A USB Modular Function/
Arbitrary Waveform Generator
Service Guide
4
Disassembly
General Disassembly 54
Replacement Parts 56
This chapter describes the procedure to disassemble the U2761A. The information
on the replacement parts is also provided.
53
4
Disassembly
General Disassembly
This chapter provides the step-by-step guide to dismantle the module. To
reassemble the module, follow the instructions in reverse order.
The removable assemblies include the following.
– Front and back bumpers
– Metal casing
– Rear metal casing
– Front metal casing, which is attached to the carrier board and measurement
board
Disassembly Instructions
NOTE
The parts shown in the following figures are representative and may look
different with what you have in your module.
Follow the instructions in this section to disassemble the U2761A.
Remove the two bumpers from the metal
casing.
54
Keysight U2761A Service Guide
Disassembly
Front metal piece
4
Remove the two indicated screws from
the front metal piece.
Screws
Gently pull the front metal piece out,
which is attached to the carrier and
measurement boards.
Rear metal piece
Remove the two indicated screws and
proceed to remove the rear metal piece
Screws
Keysight U2761A Service Guide
55
4
Disassembly
Reassembly Instructions
The reassembly process is simply the reverse of disassembly.
Replacement Parts
This section provides the information of orderable replacement parts for the
U2761A. You can order the replacement parts through Keysight website or you
can contact the nearest Keysight Sales Office or Service Centre. To search for the
replacement part number online, follow the steps below.
1 Launch your Internet Explorer to access Keysight website (www.keysight.com).
2 On the technical support panel, select Test & Measurement under the Parts
Information selection as shown below.
56
Keysight U2761A Service Guide
Disassembly
4
3 You can search for the replacement parts by entering a specific replacement
part number or by instruments.
– To search by part number, type the replacement part number in the text
box as shown below.
– To search by instrument, type the model number in the text box and click
View Parts to select a particular replacement part.
4 The result of your search will appear and click View Parts for the selected
instrument.
Keysight U2761A Service Guide
57
4
Disassembly
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58
Keysight U2761A Service Guide
Keysight U2761A USB Modular Function/
Arbitrary Waveform Generator
Service Guide
5
Troubleshooting
Troubleshooting
60
This chapter provides the general information to troubleshoot the U2761A.
59
5
Troubleshooting
Troubleshooting
This section offers suggestions for solving general problems that you may
encounter with the U2761A. It guides you on what to check in the following
situations.
– Power ind icator LED is not lit.
Verify that the AC power cord is connected to the power inlet of the U2761A.
– Power ind icator LED is lit but the USB ind icator LED is not lit.
Verify that the USB cable is properly connected to the PC and USB inlet of the
U2761A.
NOTE
60
If there is no response from the instrument, contact the nearest keysight Service
Center to obtain further assistance.
Keysight U2761A Service Guide
Index
A
K
U
accuracy, 20, 24, 26, 28, 29
Adjustment, 49
adjustment
+20 dB range flatness, 49
0 dB range flatness, 47
-20 db range AC flatness, 45
AC amplitude, 42
DC offset, 41
output impedance, 40
timebase, 39
ambient, 25
relative humidity, 25
temperature, 25
Keysight
calibration services, 20
measurement manager, 18
recommended models, 24
USB,
oscilloscope, 24
output impedance,
C
P
calibration
constant, 40, 41, 44, 47, 49,
51
interval, 20
procedure, 38
recommended test
equipment, 24
D
DC, 24, 28, 29, 41
disassembly, 22, 56
DMM, 24, 27, 28, 29, 40, 41, 42
F
frequency counter,
24, 26, 39
H
humidity
ambient relative,
25
I
internal timebase
verification, 26
Keysight U2761A Service Guide
L
LED,
60
O
40
60
V
verification, 26
-20 dB range AC
flatness, 31, 34, 36
AC amplitude, 29
DC offset, 28
internal timebase, 26
W
warm-up,
warranty,
25
20, 21
Power Meter, 50
Power meter, 46, 48
power meter, 24, 31, 32, 34, 36,
45, 47, 49
power sensor, 24
pulse, 44
R
reassembly, 56
recommended test
equipment, 24
repackaging, 22
repair service, 21
S
self-test, 18
service, 20, 21, 22
services, 20
spectrum analyzer, 25
T
test consideration, 25
troubleshooting, 60
61
THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK.
62
Keysight U2761A Service Guide
This information is subject to change
without notice. Always refer to the
Keysight website for the latest
revision.
© Keysight Technologies 2008 - 2017
Edition 8, June 1, 2017
Printed in Malaysia
*U2761-90010*
U2761-90010
www.keysight.com
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