Keysight Technologies 423B Service manual

Keysight 423B and 8470B
Detectors
Operating and
Service Manual

2 Keysight 423B and 8470B Operating and Service Manual
Notices
Copyright Notice
© Keysight Technologies 2014 - 2019
No part of this manual may be reproduced in
any form or by any means (including electronic
storage and retrieval or translation into a for-
eign language) without prior agreement and
written consent from Keysight Technologies as
governed by United States and international
copyright laws.
Manual Part Number
00423-90103
Edition
Edition 3, January 15, 2019
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 down-
loaded from the Web. Go to http://www.key-
sight.com/go/conformity. You can then search
by product number to find the latest Declara-
tion of Conformity.
U.S. Government Rights
The Software is “commercial computer soft-
ware,” as defined by Federal Acquisition Regu-
lation (“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.key-
sight.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 documenta-
tion that is not customarily provided to the
public; or (2) Relinquish to, or otherwise pro-
vide, the government rights in excess of these
rights customarily provided to the public to
use, modify, reproduce, release, perform, dis-
play, or disclose commercial computer soft-
ware 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.
Warranty
THE MATERIAL CONTAINED IN THIS DOCU-
MENT IS PROVIDED “AS IS,” AND IS SUBJECT
TO BEING CHANGED, WITHOUT NOTICE, IN
FUTURE EDITIONS. FURTHER, TO THE MAXI-
MUM EXTENT PERMITTED BY APPLICABLE
LAW, KEYSIGHT DISCLAIMS ALL WARRAN-
TIES, EITHER EXPRESS OR IMPLIED, WITH
REGARD TO THIS MANUAL AND ANY INFOR-
MATION CONTAINED HEREIN, INCLUDING
BUT NOT LIMITED TO THE IMPLIED WARRAN-
TIES 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 DOCU-
MENT 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 CON-
FLICT 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 pro-
ceed beyond a CAUTION notice until the indi-
cated 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 423B and 8470B Operating and Service Manual 3
Certification
Keysight Technologies certifies that this product met its published
specifications at the time of shipment from the factory. Keysight Technologies further certifies that
its calibration measurements are traceable to the United States National Institute of Standards and
Technology (NIST, formerly NBS), to the extent allowed by the Institute’s calibration facility, and to
the calibration facilities of other International Standards Organization members.
Assistance
Product maintenance agreements and other customer assistance agreements are available for
Keysight Technologies products.
For assistance, call your local Keysight Technologies Sales and Service Office.
Any adjustment, maintenance, or repair of this product must be performed by qualified personnel.
Contact your customer engineer through your local Keysight Sales and Service Center.
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.
Regulatory Markings
When you see this symbol on your instrument,
you should refer to the instrument’s instruction
manual for important information.
This symbol indicates hazardous voltages.
The laser radiation symbol is marked on products
that have a laser output.
This symbol indicates that the instrument
requires alternating current (ac) input.
This symbol indicates that the power line switch
is ON.
This symbol indicates that the power line switch
is OFF or in STANDBY position.
The CE mark is a registered trademark of the
European Community. If it is accompanied by a
year, it indicates the year the design was proven.
The CSA mark is a registered trademark of the
Canadian
Standards Association.
This text indicates that the instrument is an
Industrial Scientific and Medical Group 1 Class A
product (CISPER 11, Clause 4).
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.

4 Keysight 423B and 8470B Operating and Service Manual
Waste Electrical and Electronic Equipment (WEEE) Directive
This instrument complies with the WEEE Directive 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/detectors
(product-specific information and support, software and documentation updates)
–www.keysight.com/find/assist
(worldwide contact information for repair and service)

Keysight 423B and 8470B Operating and Service Manual 5
Table of Contents
Certification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Assistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Safety Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Regulatory Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Waste Electrical and Electronic Equipment (WEEE) Directive . . . . . . . . . . . . . . . . . . . . 4
Product category: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Sales and Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Initial inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Storage and shipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Operating Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Operator’s check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Performance Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Frequency response test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Higher level sensitivity test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Low level sensitivity test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Match test (SWR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

6 Keysight 423B and 8470B Operating and Service Manual
THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK.

Keysight 423B and 8470B Operating and Service Manual 7
List of Figures
Figure 1 Peak power measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

8 Keysight 423B and 8470B Operating and Service Manual
THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK.

Keysight 423B and 8470B Operating and Service Manual 9
List of Tables
Table 1 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

10 Keysight 423B and 8470B Operating and Service Manual
THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK.

Keysight 423B and 8470B Operating and Service Manual 11
Description
The Keysight Technologies 423B and 8470B detectors are 50 Ω(nominal) Schottky diode devices
designed for measurement use in coaxial systems.
Features
– The instruments convert the RF power levels applied to the 50 Ω input connector into
proportional values of dc voltage.
– The instruments measure relative power up to 200 mW and have a BNC female connector for
the output jack which allows the detected output to be connected to a SWR meter.
– The output voltage polarity is negative, unless Option 003 is selected.
– The frequency range of the 423B is 10 MHz to 12.4 GHz.
– The frequency range of the 8470B is 10 MHz to 18 GHz.
– AM modulation can be detected up to about 1 MHz.
Options
The 423B and 8470B detectors are available with the following non-exclusive options.
Option 001: Matched pair of detectors
Option 002: Furnished with matched load resistor for optimum square law characteristics
Option 003: Positive polarity output
Option 012: Furnished with stainless steel type-N male connectors (8470B only)
Connectors
– The mating RF input connectors used with the 423B and 8470B Option 012 must be type-N
female connectors which comply with U.S. military standard MIL-C-39012.
– The 8470B (standard) RF input connector must be an 7-mm connector.
– The mating output connector for the 423B and 8470B must be a BNC male.

12 Keysight 423B and 8470B Operating and Service Manual
Installation
Initial inspection
1Inspect 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 has been checked mechanically and electrically. Procedures
for checking electrical performance are given under “Performance Tests” on page 17.
2If the contents are incomplete, if there is mechanical damage or defect, or if the instrument
does not pass the electrical performance test, contact the nearest Keysight Technologies office.
Any adjustment, maintenance, or repair of this product must be performed by qualified
personnel. Contact your customer engineer through your local Keysight Sales and Service
Center. Refer to “Sales and Technical Support” on page 4. Keysight Technologies will arrange
for repair or replacement of the damaged or defective equipment. Keep the shipping materials
for the carrier's inspection.
3If you are returning the instrument for service, repackaging the instrument requires original
shipping containers and materials or their equivalents. Keysight can provide packaging
materials identical to the original materials. Any adjustment, maintenance, or repair of this
product must be performed by qualified personnel. Contact your customer engineer through
your local Keysight Sales and Service Center. Refer to “Sales and Technical Support” on
page 4. Attach a tag indicating the type of service required, return address, model number and
serial number. Mark the container FRAGILE to insure careful handling. In any correspondence,
refer to the instrument by model number and serial number.
Storage and shipment
The instrument should be stored in a clean, dry environment. The following environmental
limitations apply to both storage and shipment:
aTemperature –54 to +85 °C
bAltitude |7620 meters (25,000 feet)
cHumidity |95% relative
dShock 100 G for 11 ms
eVibration 20 G from 80 to 2000 Hz

Keysight 423B and 8470B Operating and Service Manual 13
Table 1 Specifications
Characteristic Value
Frequency range[a]
423B
8470B
10 MHz to 12.4 GHz
10 MHz to 18 GHz
Frequency response[b][c]
423B and 8470B
Octave flatness
Broadband flatness
±0.2 dB over any octave 10 MHz to 8 GHz
±0.3 dB 10 MHz to 12.4 GHz
8470B only:
Broadband flatness
±0.5 dB 10 MHz to 15 GHz
±0.6 dB 10 MHz to 18 GHz
SWR[d] [e] (Max)
423B and 8470B 10 MHz to 4 GHz, 1.15
4 GHz to 12.4 GHz, 1.3
8470B only 12.4 GHz to 15 GHz, 1.3
15.0 GHz to 18 GHz, 1.7
Maximum operating input power 200 mW, peak or average
Maximum short term input power 1 watt (typical) peak or average for | 1 minute
Sensitivity[c][d][f]
High level
Low level
| 0.35 mW produces 100 mV output
}0.5 mVdc/mW CW
Input impedance 50 Ω(nominal)
Output impedance 1 to 2 kΩ(typically 1.3 kΩ) shunted by 35 to 65 pF (typically 50 pF)
Output polarity Negative (refer to options for positive polarity units)
Detector element Supplied
Bias Not required
Noise |50 mVpp with CW applied to produce 100 mV output
Options
423B and 8470B
Option 002 Furnished with matched load resistor for optimum square law characteristics of 25
°C, within ±0.5 dB from square law over a range of at least
30 dB up to 10 mV peak output, working into an external load > 8 kΩ. Sensitivity
typically is greater than 0.1 mV/mW when load resistor is used
Option 003 Positive polarity output
423B
Option 001 Matched detector pair. Frequency response characteristics (exclusive of basic
sensitivity) track within ±0.2 dB from 10 MHz to 12.4 GHz at -30 dBm
8470B:
Option 001 Matched detector pair. Frequency response characteristics (exclusive of basic
sensitivity) track within ±0.2 dB from 10 MHz to 12.5 GHz; ±0.3 dB from 12.4 GHz to
18 GHz at -30 dBm.
Option 012 Furnished with stainless steel type-N male connector

14 Keysight 423B and 8470B Operating and Service Manual
Environmental
423B
Operating temperature
Humidity
Vibration
Shock
Altitude
0 °C to +55 °C
|95% relative
20 G from 80 to 2000 Hz
100 G for 11 ms
|4570 meters (15,000 feet)
8470B
Operating temperature
Humidity
Vibration
Shock
Altitude
–20°C to +85 °C
|95% relative
20 G from 80 to 2000 Hz
100 G for 11 ms
|4570 meters (15,000 feet)
General
Weight
423B and 8470B Net 114 g (4 oz.)
Dimensions
423B
8470B
63 mm long, 20 mm diameter (2.47 in. long, 0.78 in. diameter)
64 mm long, 19 mm diameter (2.50 in. long, 0.75 in. diameter)
[a] RF may leak through the output connector below 1 GHz. It can be reduced, if objectionable, with a suitable low pass filter.
[b] Measured at –30 dBm. Flatness is the peak-to-valley range of the response.
[c] External load resistance }50 kΩ
[d] Specifications given for +25 °C unless otherwise noted.
[e] Measurement made at –20 dBm.
[f] Sensitivity decreases with increasing temperature, typically: 0.5 dB from −20 to +25 °C; 0.5 dB from +25 to +40 °C; 1 dB from +40 to +55
°C; 1.25 dB from +55 to +75 °C; 1 dB from +75 to +85 °C.
Table 1 Specifications (continued)
Characteristic Value

Keysight 423B and 8470B Operating and Service Manual 15
Operating Information
The detector can be used as a demodulator to obtain a pulse envelope which can then be observed
on an oscilloscope. It can also be used as a general purpose detector.
The power applied to the detector can be either modulated or continuous wave (CW). If modulated
at a 1000 Hz rate, an SWR meter can be used as an indicator. For CW detection, a dc milliammeter
or millivoltmeter can be used as the indicator.
CAUTION
Static discharge can damage the detector element. A 100 pF capacitor (1.2 m [4 ft] of coax
cable) charged to 14 volts stores .1 erg, the maximum pulse rating of the detector element.
– Connect cables to test equipment and discharge the center conductor before connecting
to the detector.
– DO NOT NEEDLESSLY HANDLE THE DETECTOR ELEMENT USED IN CRYSTAL DETECTOR.
Static electricity which builds up on a person, especially on a cold dry day, must never be
allowed to discharge through the detector.
– Avoid exposed leads to or from the detector, since these are often touched accidentally.
NOTE
When using the detector with an oscilloscope, and the waveshapes to be observed have rise
times of less than 5 µs, the coaxial cable connecting oscilloscope and detector should be as short
as possible and shunted with a resistor.
Ideally, this resistor should be 50 Ωto terminate the coaxial cable properly. However, with 50 Ω
resistance, the output video pulse may be too small to drive some oscilloscopes. Therefore, the
cable should be shunted with the smallest value of resistance that will obtain suitable deflection
on the oscilloscope; typically the value will lie between 50 Ωand 2 kΩ. The larger the resistance
the more degradation of rise time.

16 Keysight 423B and 8470B Operating and Service Manual
Operator’s check
Peak power measurement
The procedure for peak power measurement involves calibration of an oscilloscope which, in turn,
is used to calibrate a CW generator. The output of the calibrated CW generator is measured with a
power meter; the peak power of a pulse is thereby measured. The procedure is as follows:
1Connect equipment as shown in Figure 1, step A. Observe the pulse on a decoupled
oscilloscope. Using a marking pencil, mark on the graticule the base-to-peak amplitude of the
pulse envelope.
2Replace the pulse source with a CW generator. While observing the oscilloscope trace, adjust
the amplitude of CW generator output to make detector's output equal to that of pulse
generator, as indicated by markings on the graticule (step A).
3Leave the CW generator at setting obtained in step B. Disconnect the detector from CW
generator.
4Connect the output of CW generator to the power meter (step C). Measure the adjusted levels
(set in step B) of the CW generator output. The peak power of the pulse envelope observed in
step A is equal to the output power of the CW generator.
Figure 1 Peak power measurement
Reflectometer application
For information about reflectometer systems and measurements refer to Keysight Technologies
Application Note Index. Copies are available upon request.
Harmony frequency comparison measurement application
The detector can be used as a mixer in harmonic-frequency comparison measurements. Refer to
Keysight Technologies Application Note Index for further information.

Keysight 423B and 8470B Operating and Service Manual 17
Performance Tests
Methods for testing detector specifications are given below. Refer to the manuals of the equipment
involved for operating instructions.
Frequency response test
1Using signal sources covering 10 MHz to 18 GHz with a 10 dB isolating attenuator and a power
meter, connect the power sensor to the attenuator. Adjust the RF power level to –20 dBm input
to the power sensor.
2Without changing the RF power level of signal source, disconnect the power sensor.
3Connect the detector to the attenuator. Measure the dc voltage output and record the
measurement.
4Change the frequency of the signal source and repeat steps 1 through 3.
5Since the detector follows a square-law response at this power level, its output is proportional
to power (PdB = 10 log Vo). Total variation of detector readings should meet specifications for all
frequencies of interest across the band.
Higher level sensitivity test
1Using signal sources covering 10 MHz to18 GHz and a dc voltmeter or oscilloscope as the
indicator, connect the detector to the signal source. Adjust the RF power level for a 100 mV
detected output from the detector, using a CW signal.
2Disconnect the detector from the signal source and measure the RF output level. The RF output
level should be ≤ 0.35 mW.
3Repeat steps 1 and 2 for all frequencies of interest across the band.
Low level sensitivity test
1Using a signal source (covering 10 MHz to 18 GHz), a 10 dB attenuator, and a power meter,
connect the attenuator to the signal source and power sensor to the attenuator. Adjust the RF
power level for -20 dBm output from the attenuator. Verify the ambient temperature.
2Disconnect the power sensor from the attenuator and connect the detector. Measure the dc
voltage output from the detector. The output should be }5.0 mV at 25× °C. Between 20× °C and
30× °C, the sensitivity slope is typically –0.04 dB/× °C.
Match test (SWR)
1To verify the detector's SWR specifications, use any system whose measurement accuracies for
SWR (residual SWR) are known.
NOTE
Multiple mismatch errors caused by attenuator SWR, power meter SWR, and detector SWR
should be taken into account, as well as the accuracy of the indicator used to measure the
detector's output.

18 Keysight 423B and 8470B Operating and Service Manual
Service
The 423B and 8470B does not have internal adjustments and should not be opened; it should only
be repaired by service-trained personnel. Should it become necessary to return the 423B and
8470B for repair or service, contact your nearest Keysight Sales and Service Center. Refer to “Sales
and Technical Support” on page 4 of this manual.

This information is subject to change
without notice. Always refer to the
Keysight website for the latest
revision.
© Keysight Technologies 2014 - 2019
Edition 3, January 15, 2019
Printed in Malaysia
*00423-90103*
00423-90103
www.keysight.com