Used Agilent Agilent Used 346A Manual

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Keysight 346A/B/C Noise
Source (Including Options
001 and 004)

Instruments with serial prefixes 4124A and above are
supplied with the noise source ENR data preloaded on a
diskette - see Chapters 3 and 4.

Instruments with serial prefixes MY5823 and above are
supplied with the noise source ENR data preloaded on a
CD - see Chapters 3 and 4.

Operating and
Service Manual

Notices

CAUTION

WARNING

Copyright Notice

© Keysight Technologies 2001 - 2018
No part of this manual may be repro-

duced 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.

Manual Part Number

00346-90148

Edition

Edition 4, July 26, 2018

Printed in:

Printed in Malaysia

Published by:

Keysight Technologies
Bayan Lepas Free Industrial Zone,
11900 Penang, Malaysia

Technology Licenses

The hard ware 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.

U.S. Government Rights

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). The license set
forth in the EULA represents the
exclusive authority by which the U.S.
government may use, modify,
distribute, or disclose the Soft-ware.
The EULA and the license set forth
therein, does not require or per-mit,
among other things, that Keysight: (1)
Furnish technical information related to
commercial computer
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, per-form,
display, or
computer software
com-puter software documentation.
No additional government
requirements beyond those set forth in
the EULA shall apply, except to the
extent
licenses are explicitly required from all
providers of commercial computer
software pursu-ant to the FAR and the
DFARS and are set forth specifically in
writing
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.

disclose commercial

that those terms, rights, or

else-where in the EULA.

soft-ware or

or commercial

Warranty

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

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.

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.

2 Keysight 346A/B/C Operating and Service Manual

Environmental Conditions

The instrument is designed for indoor use and in an area with low condensation.
The table below shows the general environmental requirements for this
instrument.

Environmental condition Requirement

Temperature

Humidity <95% RH

Altitude

Operating condition
– 0 °C to 55 °C
Storage/shipment condition
– –55 °C to 75 °C

Operating condition
– <4600 m (15000 ft)
Storage/shipment condition
– <15300 m (50000 ft)

Keysight 346A/B/C Operating and Service Manual 3

Safety Symbols

The following symbols on the instrument and in the manual indicate precautions
which must be taken to maintain safe operation of the instrument.

The Instruction Documentation
Symbol. The product is marked with
this symbol when it is necessary for the
user to refer to the instructions in the
supplied documentation.

This symbol indicates that a device, or
part of a device, may be susceptible to
electrostatic discharges (ESD) which
can result in damage to the product.
Observe ESD precautions given on the
product, or its user documentation,
when handling equipment bearing this
mark.

4 Keysight 346A/B/C Operating and Service Manual

Regulatory Information

MSIP-REM-Kst-

xxxxxxxxxxxxxx

The 346A/B/C Noise Source (including Options 001 and 004) complies with the
following Electromagnetic Compatibility (EMC) compliances:

– IEC 61326-1/EN 61326-1

– Canada: ICES/NMB-001

– Australia/New Zealand: AS/NZS CISPR11

In order to preserve the EMC performance of the product, any cable which
becomes worn or damaged must be replaced with the same type and
specification.

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.

ICES/NMB-001 indicates that this
ISM product complies with the
Canadian ICES-001.

Cet appareil ISM est conforme a la
norme NMB-001 du Canada.

ISM GRP.1 Class A indicates that
this is an Industrial Scientific and
Medical Group 1 Class A product.

Keysight 346A/B/C Operating and Service Manual 5

The RCM mark is a registered trademark of the
Australian Communications and Media Authority.

This instrument is Class A suitable for professional
use and is for use in electromagnetic environments
outside of the home.

This symbol indicates the time
period during which no hazardous
or toxic substance elements are
expected to leak or deteriorate
during normal use. Forty years is the
expected useful life of the product.

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.

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.

6 Keysight 346A/B/C Operating and Service Manual

Table of Contents

Environmental Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Safety Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Regulatory Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Regulatory markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Waste Electrical and Electronic Equipment (WEEE) Directive 2002/96/

EC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Product category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Sales and Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

1Introduction

Product Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

2Installation

Handling Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Initial Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Service and Recalibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

Instruments Covered by this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Equipment available but not supplied . . . . . . . . . . . . . . . . . . . . . . . . 22

Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

Mating connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

3 Specifications

General Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

Excess Noise Ratio expanded uncertainty (U(Y)) . . . . . . . . . . . . . . . 27

Supplemental characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

Physical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

4Operating Guide

Operating Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Recommended test equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

Keysight 346A/B/C Operating and Service Manual 7

Operator’s check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Operator’s Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Performance Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Replaceable Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Principles of operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Returning the noise source for calibration . . . . . . . . . . . . . . . . . . . . 44

5 Manual Changes

Manual Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Change A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

6 Using the ENR Data Diskette or CD

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Loading ENR Data from Diskette . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Retrieving ENR Data from CD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Saving the ENR Data to the Noise Figure Analyzer’s Internal

Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Copying the ENR Data to the Noise Figure Analyzer’s Internal

Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

7 ENR File Format

Format Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Comment records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Header fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

ENR data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Example 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Example 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

A Caring for Connectors

8 Keysight 346A/B/C Operating and Service Manual

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66

Connector part numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66

Handling and storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66

Visual Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67

Obvious defects and damage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67

Mating plane surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67

Precision 7 mm connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68

Sexed connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69

Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70

Compressed air . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70

Cleaning alcohol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Precision 7 mm connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71

Cleaning interior surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

Drying connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72

Mechanical Inspection: Connector Gages . . . . . . . . . . . . . . . . . . . . . . .73

Mechanical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

Precision 7 mm connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74

Sexed connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75

50 Ω Type-N connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75

75 Ω Type-N connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .76

Using Connector Gages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77

Inspecting and cleaning the gage . . . . . . . . . . . . . . . . . . . . . . . . . . .77

Zeroing the gage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77

Measuring connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .78

Making Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .80

Align connectors carefully . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .80

To make a preliminary connection . . . . . . . . . . . . . . . . . . . . . . . . . .81

Final connection using a torque wrench . . . . . . . . . . . . . . . . . . . . . .81

Disconnection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .83

Adapters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .84

Principles of Microwave Connector Care . . . . . . . . . . . . . . . . . . . . . . . .86

Keysight 346A/B/C Operating and Service Manual 9

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10 Keysight 346A/B/C Operating and Service Manual

List of Figures

Figure 1-1 A partial view of typical calibration label . . . . . . . . . . .16

Figure 3-1 Characteristic ENR plot versus cardinal frequency

Figure 4-1 Typical noise figure measurement test setup . . . . . . .32

Figure 4-2 Operator’s check test setup 1 . . . . . . . . . . . . . . . . . . .34

Figure 4-3 Operator’s check test setup 2a . . . . . . . . . . . . . . . . . .35

Figure 4-4 Operator’s check test setup 2b . . . . . . . . . . . . . . . . . .36

Figure 4-5 Typical example of power reading with Noise

Figure 4-6 Typical example of power reading with Noise

Figure 4-7 Preparing for parts removal/replacement . . . . . . . . . .42

Figure 4-8 Simplified diagram of the noise source . . . . . . . . . . . .43

Figure A-1 Precision 7 mm connector . . . . . . . . . . . . . . . . . . . . . .68

Figure A-2 Precision 3.5 mm connectors . . . . . . . . . . . . . . . . . . . .69

Figure A-3 SMA connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69

Figure A-4 Cleaning interior surfaces . . . . . . . . . . . . . . . . . . . . . .72

Figure A-5 Type-N connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . .75

Figure A-6 Using the connector gage . . . . . . . . . . . . . . . . . . . . . .78

points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28

Source On . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Source Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

Keysight 346A/B/C Operating and Service Manual 11

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12 Keysight 346A/B/C Operating and Service Manual

List of Tables

Table 1-1 Model characteristics of individual noise sources . . . .17

Table 2-1 Connectors that can be mated with the noise

sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

Table 3-1 346A/B/C specifications . . . . . . . . . . . . . . . . . . . . . . . 26

Table 3-2 Characteristic ENR (U(Y)) specification . . . . . . . . . . . .28

Table 3-3 Supplemental characteristics . . . . . . . . . . . . . . . . . . .29

Table 3-4 Physical specifications . . . . . . . . . . . . . . . . . . . . . . . . .29

Table 4-1 Recommended test equipment for operator’s

checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

Table 4-2 Replaceable parts list for 346A . . . . . . . . . . . . . . . . . .41

Table 4-3 Replaceable parts list for 346B and 346C . . . . . . . . . .41

Table 4-4 Replaceable labels list . . . . . . . . . . . . . . . . . . . . . . . . .41

Table 5-1 Manual changes by serial number . . . . . . . . . . . . . . . .46

Table 7-1 Mandatory header fields . . . . . . . . . . . . . . . . . . . . . . .57

Table 7-2 Optional header fields . . . . . . . . . . . . . . . . . . . . . . . . .57

Table A-1 Recommended connector gages . . . . . . . . . . . . . . . . .73

Table A-2 Recommended torque settings . . . . . . . . . . . . . . . . . . 82

Table A-3 Adapters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .85

Table A-4 Principles of microwave connector care . . . . . . . . . . .86

Keysight 346A/B/C Operating and Service Manual 13

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14 Keysight 346A/B/C Operating and Service Manual

Keysight 346A/B/C Noise Source
Operating and Service Manual

1 Introduction

Product Overview 16

This chapter provides an overview of the Keysight 346A/B/C Noise Source.

15

1Introduction

Product Overview

The Keysight 346A/B/C noise source produces noise output (power-on) when
+28 V is applied. When it is off, there is residual noise due to thermal agitation in
the noise source (power-off). These two noise levels are used to measure the gain
and added noise of the device under test, and consequently, its noise figure.

The Excess Noise Ratio (ENR) for each noise source has been measured at major
frequencies and recorded on a label attached to the noise source (see Figure 1-1).
ENR references power-on to the noise power that exists at 290 Kelvin (17 °C). In
addition, a separate calibration sheet showing the complex reflection coefficient
in both the on and off states is included with each instrument.

All three models are provided with a BNC female connector for power input. The
output connector is a male APC-3.5 on the standard noise sources. Type-N
connectors are available as options for the Keysight 346A and 346B noise sources.
In addition to these general characteristics, certain characteristics apply to the
specific models. These characteristics are listed in Tab le 1-1.

Figure 1-1 A partial view of typical calibration label

16 Keysight 346A/B/C Operating and Service Manual

Introduction 1

Table 1-1 Model characteristics of individual noise sources

Keysight 346A Keysight 346B Keysight 346C

Reflection coefficient differential
between on and off states is
specified to be no greater than

0.01.

Specified output noise spectrum
from 10 MHz to 18 GHz.

Nominal ENR is 6 dB over the
specified frequency range.

Not directly usable for Keysight
8970A IF attenuator calibration
(Special Function 33). 10 dB of
gain is required.

Not directly usable for Keysight
8970B IF attenuator calibration.
Refer to “Calibration, IF
Attenuators” in the Keysight
8970B Operating Manual.

Reflection coefficient differential
between on and off states is not
specified, but is less than 0.1
typically.

Specified output noise spectrum
from 10 MHz to 18 GHz.

Nominal ENR is 15 dB over the
specified frequency range.

Suitable for Keysight 8970A IF
attenuator calibration (Special
Function 33).

Suitable for Keysight 8970B IF
attenuator calibration. Refer to
“Calibration, IF Attenuators” in
the Keysight 8970B Operating
Manual.

Reflection coefficient differential
between on and off states is not
specified, but is less than 0.1
typically.

Specified output noise spectrum
from 10 MHz to 26.5 GHz.

Nominal ENR is 15 dB over the
specified frequency range.

Suitable for Keysight 8970A IF
attenuator calibration (Special
Function 33).

Suitable for Keysight 8970B IF
attenuator calibration. Refer to
“Calibration, IF Attenuators” in
the Keysight 8970B Operating
Manual.

Keysight 346A/B/C Operating and Service Manual 17

1Introduction

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18 Keysight 346A/B/C Operating and Service Manual

Keysight 346A/B/C Noise Source
Operating and Service Manual

2 Installation

Handling Precautions 20
Initial Inspection 20
Service and Recalibration 21
Instruments Covered by this Manual 21

This chapter provides you important information on how to check and prepare
your instrument for operation.

19

2Installation

CAUTION

CAUTION

Handling Precautions

Do not disassemble the noise source. The diode module is static sensitive
and can be damaged or the calibration can be altered.

Do not drop the noise source. Dropping can damage the unit or alter the
calibration.

Proper connector care is essential. See “Operator’s Maintenance” on page 39 for
more information.

Initial Inspection

1 Unpack and inspect the shipping container and its contents thoroughly to

ensure that nothing was damaged during shipment. If the shipping container
or cushioning material is damaged, the contents should be checked both
mechanically and electrically.

– Check for mechanical damage such as scratches or dents.

– Procedures for checking electrical performance are given under “Operator’s

check” on page 33.

2 If the contents are damaged or defective, contact your nearest Keysight

Technologies Service and Support Office. Refer to “Sales and Technical

Support” on page 6 of this manual. Keysight Technologies will arrange for

repair or replacement of the damaged or defective equipment. Keep the
shipping materials for the carrier’s inspection.

3 If you are returning the instrument under warranty or for service, repackaging

the instrument requires original shipping containers and material or their
equivalents. Keysight Technologies can provide packaging materials identical
to the original materials. Refer to “Sales and Technical Support” on page 6 of
this manual for the Keysight Technologies nearest to you. 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.

20 Keysight 346A/B/C Operating and Service Manual

Service and Recalibration

If your 346A/B/C requires service or repair, contact the nearest Keysight office for
information on where to send it. The performance of the 346A/B/C can only be
verified by specially-manufactured equipment and calibration standard from
Keysight. The recommended interval for recalibration is 12 months.

Instruments Covered by this Manual

The noise sources covered by this manual have a two-part serial number. The first
four digits and letter constitute the serial number prefix. The last five digits form a
sequential suffix that is unique to each noise source. The prefix is the same for all
noise sources of a particular configuration. It will change when a design
modification occurs. The contents of this manual apply directly to those
instruments having the same serial number prefixes listed on the title page.

A noise source manufactured after the printing of this manual may have a serial
number prefix which is not listed on the title page. This unlisted serial number
prefix indicates the noise source is different than those documented in this
manual. If manual changes are needed, the manual for this newer noise source is
accompanied by a Manual Changes supplement. The supplement contains
“change information” that explains how to adapt this manual to the newer noise
source.

In addition to change information, the supplement may contain information for
correcting errors in the manual. The supplement is identified with the manual print
date and part number, both of which appear on the manual title page.

Installation 2

For information concerning a serial number prefix that is not listed on the title
page in the Manual Change supplement, contact your nearest Keysight
Technologies office.

Keysight 346A/B/C Noise Source which was manufactured before the printing of
this manual will have a serial number prefix lower than the one listed on the title
page. Manual changes for these older models are found in Chapter 5, “Manual

Changes”.

Keysight 346A/B/C Operating and Service Manual 21

2Installation

NOTE

NOTE

Keysight Technologies are migrating their existing product serial numbers to a
new format. All new products use this new format. The format is the first two
letters signify the country of manufacture, for example, US representing the
USA, the next four numbers, the serial number prefix, and the last five numbers
form a sequential suffix that is unique to each product. For example,
US123456789, where 1234 is the prefix and 56789 is the suffix. The two letters
MY represent Malaysia.

Equipment available but not supplied

The following equipment is available from Keysight Technologies for use with the
noise sources:

– 8710-1766: 3/4" torque wrench (APC-7)

– 5060-0344: 9/16" torque wrench (APC-3.5)

Keysight Model 346B Noise Sources with serial prefixes of 2037A and below,
have an APC-3.5 connector of a different configuration. The 9/16" torque wrench
will not fit these older models.

Options

The Keysight 346A and 346B Noise Sources are available with the following
output connector options:

– Option 001, Type-N (male)

– Option 004, Type-N (female)

Since the Type-N connectors do not operate up to 26.5 GHz, no output connector
options are available for the Keysight 346C.

22 Keysight 346A/B/C Operating and Service Manual

Mating connectors

The noise sources can be mated with other instrumentation having the connectors
listed in Table 2-1.

Table 2-1 Connectors that can be mated with the noise

Configuration Mating connector

Input: all units

Output: standard

Opt 001

Opt 004

[a] Must comply with U.S. Military Standard MII,C-39012.

sources

BNC male

– APC-3.5 female
– SMA female

Type-N female

Type-N male

[a]

[a]

[a]

Installation 2

Keysight 346A/B/C Operating and Service Manual 23

2Installation

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24 Keysight 346A/B/C Operating and Service Manual

Keysight 346A/B/C Noise Source
Operating and Service Manual

3 Specifications

General Specifications 26

This chapter provides the specifications of the 346A/B/C Noise Source.

25

3 Specifications

General Specifications

Specifications

The specifications in Table 3-1 are performance standards or limits against which
the noise source may be tested. These specifications for the noise source when
used with a Noise Figure Analyzer are ONLY valid if the analyzer has been allowed
to meet its specified warm up time of 60 minutes.

ENR expanded uncertainty analysis and supplemental characteristics are not
specifications but are typical characteristics included as additional information.

Tab le 3-1 346A/B/C specifications

Specification 346A 346B 346C

Frequency range 10 MHz to 18 GHz 10 MHz to 18 GHz 10 MHz to 26.5 GHz

Operating temperature 0 °C to 55 °C 0 °C to 55 °C 0 °C to 55 °C

Excess Noise Ratio (ENR)

[a]

range

Maximum Standing Wave
Ratio (SWR)

[for source ON/OFF
states]

Reflection Coefficient
(Rho) (r)

[for source ON/OFF

[b]

states]

Impedance 50 Ω nominal 50 Ω nominal 50 Ω nominal

Maximum reverse power 1 watt 1 watt 1 watt

Power required

Connectors

[c]

4.5 to 6.5 dB 14 to 16 dB 12 to 17 dB

<1.3:1 (0.01 to 0.03 GHz)
<1.15:1 (0.03 to 5.0 GHz)
<1.25:1 (5.0 to 18.0 GHz)

0.13 (0.01 to 0.03 GHz)

0.07 (0.03 to 5.0 GHz)

0.11 (5.0 to 18.0 GHz)

28 ±1 V (60 mA peak, 30 mA

average for source ON)

Output: APC-3.5 (male)

Input: Bias: BNC (f)

standard

[d]

<1.3:1 (0.01 to 0.03 GHz)
<1.15:1 (0.03 to 5.0 GHz)
<1.25:1 (5.0 to 18.0 GHz)

0.13 (0.01 to 0.03 GHz)

0.07 (0.03 to 5.0 GHz)

0.11 (5.0 to 18.0 GHz)

28 ±1 V (60 mA peak, 30 mA

average for source ON)

Output: APC-3.5 (male)

Input: Bias: BNC (f)

standard

[d]

<1.25:1 (0.01 to 18.0 GHz)
<1.35:1 (18.0 to 26.5 GHz)

0.11 (0.01 to 18.0 GHz)

0.15 (18.0 to 26.5 GHz)

28 ±1 V (45 mA)

Output: APC-3.5 (male)

Input: Bias: BNC (f)

standard

[d]

26 Keysight 346A/B/C Operating and Service Manual

Specifications 3

[a] ENR values are given at cardinal frequency points over the frequency range of each noise source. Calibrated values at cardinal frequencies

printed on each noise source label and on a separate report supplied with each Keysight 346A/B/C Noise Source. Specifications are valid at
calibration temperature only.

[b] Maximum change in complex reflection coefficient between source ON and source OFF at all frequencies for 346A only: 0.01.

[c] For correct connector usage, refer Tab le A -2 for the torque settings.

[d] Also mates with female SMA connectors. See option information for other connector styles.

Excess Noise Ratio expanded uncertainty (U(Y))

ENR values are given at cardinal frequency points over the frequency range of
each noise source. These ENR values are printed on the noise source label and on
a separate printed report supplied with the 346A/B/C Noise Source. Included in
the printed report is the measurement uncertainty for each cardinal frequency
point.

A significant proportion of the expanded uncertainty (U(Y)) is based on the
uncertainties provided by the United States National Institute of Standards and
Technology (NIST) and/or The United Kingdom National Physics Laboratories
(NPL). Keysight therefore reserve the right to change the overall expanded
uncertainties based on changes in uncertainty values within the National
Standards Institutes.

Uncertainties are valid at the ambient temperature of 23 °C ±1 °C (296 K) only.

A typical characteristic plot of ENR (U(Y)) versus each cardinal frequency point is
shown in Figure 3-1. The uncertainties given are typical — refer to the printed
calibration report for the actual uncertainties for your noise source.

Keysight 346A/B/C Operating and Service Manual 27

3 Specifications

Figure 3-1 Characteristic

[1]

ENR plot versus cardinal frequency

points

Tab le 3-2 Characteristic ENR (U(Y)) specification

Specification 346A 346B 346C

0.21 (0.01 to 1.5 GHz)

ENR uncertainty (±dB)

[a] Characteristic values are met or bettered by 90% of instruments with 90% confidence.

[a]

[1] Characteristic values are met or bettered by 90% of instruments with 90% confidence.

0.20 (1.5 to 3.0 GHz)

0.20 (3.0 to 7.0 GHz)

0.23 (7.0 to 18.0 GHz)

0.20 (0.01 to 1.5 GHz)

0.19 (1.5 to 3.0 GHz)

0.20 (3.0 to 7.0 GHz)

0.23 (7.0 to 18.0 GHz)

0.22 (0.01 to 1.5 GHz)

0.19 (1.5 to 3.0 GHz)

0.20 (3.0 to 7.0 GHz)

0.28 (7.0 to 18.0 GHz)

0.34 (18.0 to 26.5 GHz)

28 Keysight 346A/B/C Operating and Service Manual

Supplemental characteristics

Table 3-3 Supplemental characteristics

Characteristic 346A/B/C

ENR variation with temperature <0.01 dB/°C for 30 MHz to 26.5 GHz

ENR variation with voltage Internal current regulator for <0.02 dB variation for 28 ±1 V

Switching speed

Physical specifications

Specifications 3

For repetitive operation (in previous state for less than 5 seconds):
– Turn-on: < 20 μs
– Turn-off: <80 μs

For single-shot operation (in previous state more than 5 seconds):
– Turn-on: < 3 ms
– Turn-off: <80 μs

Table 3-4 Physical specifications

Specifications 346A/B/C

Net weight 0.1 kg (3.5 oz.)

Dimensions 140 × 21 × 31mm (5.5 × 0.8 × 1.2 in)

Keysight 346A/B/C Operating and Service Manual 29

3 Specifications

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30 Keysight 346A/B/C Operating and Service Manual

Keysight 346A/B/C Noise Source
Operating and Service Manual

4 Operating Guide

Operating Instructions 32
Operator’s Maintenance 39
Performance Tests 40
Adjustments 40
Replaceable Parts 40
Service 43

This chapter provides simple quick-check instructions to verify the 346A/B/C
noise source’s functionality prior to usage. It also provides information on service
and maintenance of the 346A/B/C.

31

4 Operating Guide

CAUTION

NOTE

Operating Instructions

This section refers to operation with noise figure meters. For more detailed
operating instructions, refer to the operating manual for the noise figure meter
used.

Use a DC blocking capacitor to protect the noise source from damage when
connected to any system where a DC voltage is present on the output center
conductor.

Noise figure measurements of devices (such as amplifiers, mixers, transistors, and
receivers) can be made using the noise source with a noise figure meter.

Figure 4-1 depicts a simple test setup for a noise figure measurement.

The noise figure meter must have a +28 ±1 V switch supply.

Figure 4-1 Typical noise figure measurement test setup

32 Keysight 346A/B/C Operating and Service Manual

Recommended test equipment

Table 4-1 is a list of equipment that can be used to perform an operational

verification check.

Table 4-1 Recommended test equipment for operator’s

checks

Check no. Instrument Critical specification Recommended model

Operating Guide 4

Power meter and
power sensor

1

Power supply

2 Noise figure meter

Operator’s check

The operator’s checks in this section should be performed if failure of the noise
source is suspected. The checks can be used only to verify that the noise sources
are producing a broadband noise spectrum. They cannot be used to check the
units against specifications. Only one of the checks is necessary to verify
operation. Tabl e 4-1 shows the recommended test equipment used for each
check.

Operator’s check with power meter (Check 1)

1 Connect the equipment as shown in Figure 4-2.

– Minimum sensitivity: 0.1 nW
– Frequency range: 10 MHz to 18 GHz

– Voltage: 28.0 ±1.0 V
– Current: 100 mA

– Voltage output: 28.0 ±1.0 V
– Input noise figure: <7.4 FdB at

100 MHz

Keysight E4418A with
Keysight 8481D, or
E4412A, or E9300A

Keysight 6028A

Keysight 8970B or
Keysight N8972/3/4/5A

Keysight 346A/B/C Operating and Service Manual 33

4 Operating Guide

Figure 4-2 Operator’s check test setup 1

2 Turn the power supply OFF. Zero the power meter.

3 Turn the power supply ON (+28 V). Measure the power output with the noise

4 Verify that the result of the measurement is within the following limits and

source on.

hence the noise source is operating correctly:
– Keysight 346A power output: –66 ±4 dBm
– Keysight 346B power output: –56 ±4 dBm
– Keysight 346C power output: –56 ±4 dBm

Operator’s check with Keysight 8970B noise figure meter (Check 2a)

1 Remove any cables from the noise figure meter input. Press PRESET. After

5 seconds, verify that the noise figure display shows --FdB and the left display
shows 30 MHz.

2 Connect the equipment as shown in Figure 4-3.

34 Keysight 346A/B/C Operating and Service Manual

Operating Guide 4

Figure 4-3 Operator’s check test setup 2a

3 Enter a tuned frequency of 100 MHz. (See “Fixed Frequency Tuning” in the

Keysight 8970B Operating Manual.)

4 Enter special function 5.3 to enable the instrument for spot ENR entry. (See

“Special Functions” in the Keysight 8970B Operating Manual.)

5 Enter the ENR at 100 MHz from the noise source calibration label. (See “Spot

ENR, T

hot

, and T

”, in the Keysight 8970B Operating Manual.)

Cold

6 Confirm that the noise source is operating correctly.

The noise figure measurement of the noise figure meter will appear in the noise
figure display. If the result of the measurement is less than 7.4 FdB, the noise
source is operating.

7 Press PRESET to return the instrument to preset conditions.

Keysight 346A/B/C Operating and Service Manual 35

4 Operating Guide

NOTE

Operator’s check with Keysight N8972/3/4/5AB noise figure analyzer
(Check 2b)

1 Remove any cables from the NFA input and the noise source drive.

2 Press the Preset key.

The preset condition used is the NFA default of Preset (Factory).

3 Connect the 346A/B/C to the NFA Input port using a BNC cable, as shown in

Wait until the preset routine has completed before proceeding.

Figure 4-4.

Figure 4-4 Operator’s check test setup 2b

4 Press the ENR key.

5 Press the ENR Table menu key.

6 Press the Edit Table menu key.

7 Press the Clear Table menu key.

8 Enter 100 MHz in the Frequency column of the table: Press 1, 0, 0 on the

numeric keypad followed by the MHz menu key.

36 Keysight 346A/B/C Operating and Service Manual

Operating Guide 4

9 Press the Tab key to highlight the ENR Value column of the table.

10 Enter the ENR value of the 346A/B/C at 100 MHz (0.1 GHz) using the numeric

keypad followed by the dB menu key.

11 Press the Frequency/Points key.

12 Press the Frequency Mode menu key.

13 Press the Fixed menu key.

14 Press the Fixed Frequency menu key.

Enter 100 MHz as a fixed frequency value, by pressing the 1, 0, 0 numeric keys
followed by pressing the MHz menu key.

15 Press the Sweep key.

16 Press the Manual Meas menu key.

17 Press the Manual State menu key and set it to Manual State (On).

18 Press the Noise Source menu key and set it to Noise Source (On).

19 Press the IF Att menu key and set it to IF Att (Hold).

20 Monitor the power value which appears in the manual measurement screen.

Figure 4-5 shows a typical example of this.

Figure 4-5 Typical example of power reading with Noise

Source On

Keysight 346A/B/C Operating and Service Manual 37

4 Operating Guide

NOTE

21 Press the Noise Source menu key and set it to Noise Source (Off).

22 Monitor the power value which appears in the manual measurement screen.

The monitored value is only to be used to indicate if the 346A/B/C is switching
the Excess Noise “On” and “Off” by showing a change in power value.

Figure 4-6 shows a typical example of this.

Figure 4-6 Typical example of power reading with Noise

Source Off

23 If there is no change in value, return the 346A/B/C to Keysight Technologies

for repair.

38 Keysight 346A/B/C Operating and Service Manual

Operator’s Maintenance

Proper connector care is a vital part of the maintenance which you should
perform. By following the general connector care practices outlined below, the life
of the connector can be greatly extended.

– Connectors should be properly torqued as shown below.

Connector type Torque specifications

N 1.3 N m (12 in.-lb.)

APC-7 1.3 N m (12 in.-lb.)

SMA to APC-3.5 0.9 N m (8 in.-lb.)

APC-3.5 to APC-3.5 0.9 N m (8 in.-lb.)

– Always tighten or loosen a connector by rotating only the nut. Never rotate the

noise source body.

– Use isopropyl or ethyl alcohol on a swab to clean connectors. Absorbent,

lint-free paper wrapped around the end of tweezers is recommended. Carefully
clean the conductive surfaces and avoid wetting the plastic parts inside the
connector with alcohol. After cleaning, be sure the connector is blown dry
before re-assembly.

– It is good practice to inspect a connector after cleaning. During the inspection,

check for contaminants and worn plating. Also check for a misaligned center
conductor or spread fingers on the APC-3.5 or Type-N connectors.

Operating Guide 4

– Support the cable or component attached to the connector.

– When using APC-7 connectors, the nut of one connector should always be

backed off completely and the nut on the mating connector should be
tightened. Never set an APC-7 connector on its mating surface. Before
storage, always screw the nut out to protect the surfaces.

– Be sure the connectors are axially aligned before the nut is tightened.

– Use a connector gage periodically to check the center pin depth. The shoulder

of the center conductor must never extend beyond the plane of the outer
conductor mating surface in an APC-3.5 connector.

– For more information, refer to “Appendix A: Caring for Connectors” on page 65.

Keysight 346A/B/C Operating and Service Manual 39

4 Operating Guide

NOTE

Performance Tests

Due to the complex test equipment involved, there are no recommended
performance tests to perform. Return the noise sources to Keysight Technologies
when tests are required to verify its performance and for periodic re-calibration.
The suggested interval before initial re-calibration is one year.

Adjustments

There are no adjustments that can be made on the noise sources.

Replaceable Parts

Table 4-2 and Table 4-3 list all replaceable parts available for the Keysight 346A/

B/C noise source. Figure 4-7 shows a typical noise source being prepared for
parts replacement at modular level by removing the four end screws (two at each
end).

– If the 346A/B/C is opened and parts are replaced, the noise source will

require calibration.

– Due to a parts change, adjustment of the bias current may be necessary for

the noise source to meet its ENR specifications when parts are replaced in
older units. Installation Note 00346-90137 details the adjustment process for
the 346A and 346B. Installation Note 00346-90140 details the adjustment
process for the 346C. Both are supplied with their appropriate replacement
parts.

To order parts, contact your local Keysight Sales and Service Office. Refer to

“Sales and Technical Support” on page 6 of this manual.

40 Keysight 346A/B/C Operating and Service Manual

Operating Guide 4

Table 4-2 Replaceable parts list for 346A

Keysight part number

Model/Option

Bulkhead RF

346A Std 00346-60168 00346-60194 00346-60193 00346-60194 00346-60157

– Option 001 00346-60169 00346-60194 00346-60193 00346-60194 00346-60157

– Option 004 00346-60171 00346-60194 00346-60193 00346-60194 00346-60157

Noise cartridge
kit (serial prefix
≤ MY/SG/US5322)

Noise cartridge
(serial prefix
≥ MY/SG/US5323)

Attenuator kit PC board

Table 4-3 Replaceable parts list for 346B and 346C

Keysight part number

Model/Option

346B Std 00346-60026 00346-60154 00346-60027 00346-60157

– Option 001 00346-60018 00346-60154 00346-60027 00346-60157

Bulkhead RF
replacement

Replacement noise
cartridge assembly

Replacement
attenuator assembly

Replacement PC
board assembly

– Option 004 00346-60020 00346-60154 00346-60027 00346-60157

346C Std 00346-60021 00346-60155 00346-60027 00346-60158

Table 4-4 Replaceable labels list

Part number Label description

00346-80006 346A label caution

00346-80007 346B label caution

00346-80008 346C label noise

00346-80012 Label - Blank ENR

Keysight 346A/B/C Operating and Service Manual 41

4 Operating Guide

Figure 4-7 Preparing for parts removal/replacement

42 Keysight 346A/B/C Operating and Service Manual

Service

Operating Guide 4

Principles of operation

Figure 4-8 shows a simplified diagram of the noise source. When driven by a

+28 V pulse, the 346A/B/C produces an output noise spectrum with an ENR of
approximately 5.0 dB for the 346A and approximately 15.0 dB for the 346B and
346C. The noise generator is an avalanche diode positioned into a 50 Ω system.
The noise source is divided into a DC section including a voltage converter and a
current regulator, and an RF section which includes the noise generator, a
matching network and an attenuator.

The +28 V supplies a 5.6 kHz oscillator which is rectified as the supply for the
constant current source to produce a controlled noise level output. The current
regulator controls through the noise generator diode producing a known level of
broadband noise that is constant for a supply voltage of 27 to 29 V.

Figure 4-8 Simplified diagram of the noise source

Troubleshooting

Check the connectors. If there is no apparent damage to the connectors, perform
one of the operator’s checks described in the Operating Instructions section of
this manual. If the noise source’s output does not fall within the stated range, or if
the connectors are damaged, return the unit to Keysight Technologies for repair.

Repair

Repair by the user is not recommended because of the complex equipment
required for test and calibration.

Keysight 346A/B/C Operating and Service Manual 43

4 Operating Guide

Returning the noise source for calibration

When returning the 346A/B/C to Keysight Technologies for repair or calibration,
please specify whether an ENR Data Diskette or CD is needed.

Instruments with serial prefixes MY5823 will only be provided with ENR DATA CD if
requested.

When the 346A/B/C is used with a Keysight Noise Figure Analyzer NFA, the ENR
Data Diskette is used to automatically load the ENR values into memory.

When the 346A/B/C is used with an 8970A/B Noise Figure Meter, you must enter
the ENR values manually, and the ENR Data Diskette is not necessary.

44 Keysight 346A/B/C Operating and Service Manual

Keysight 346A/B/C Noise Source
Operating and Service Manual

5 Manual Changes

Manual Changes 46

This chapter contains information for adapting this manual to Keysight 346B noise
sources with serial number prefixes of 2015A and 1935A.

45

5Manual Changes

Manual Changes

To adapt this manual to your instrument, refer to Table 5-1. Make all of the
manual changes listed opposite your instrument’s serial number prefix. Perform
these changes in the sequence listed.

Tab le 5-1 Manual changes by serial number

Instrument Serial number prefix Make manual changes

346B 1935A, 2015A A

If your instrument (all models) has a serial number prefix which is higher in value
than those listed on the title page of this manual, it may be documented in a
yellow MANUAL CHANGES supplement. For additional information, refer to

“Instruments Covered by this Manual” on page 21 in this manual.

Change A

Table 3-3 Supplemental characteristics

Change Switching Speed for both repetitive operation and single shot operation
to read: Turn off <140 μs.

46 Keysight 346A/B/C Operating and Service Manual

Keysight 346A/B/C Noise Source
Operating and Service Manual

6 Using the ENR Data

Diskette or CD

Introduction 48
Loading ENR Data from Diskette 49
Retrieving ENR Data from CD 50
Saving the ENR Data to the Noise Figure Analyzer’s Internal Memory 51
Copying the ENR Data to the Noise Figure Analyzer’s Internal Memory 53

This chapter provides the information on using the ENR data for the Keysight NFA
Series Noise Figure Analyzers.

47

6 Using the ENR Data Diskette or CD

NOTE

Introduction

The Keysight 346 and 347 series of noise sources are supplied with the noise
source ENR data preloaded on a diskette or CD to allow easy downloading into
the Keysight NFA series noise figure analyzers. This eliminates time consuming
and error prone manual keying of the ENR values.

Additionally you can easily open the ENR files using a standard text editor, and
the files are easy to interpret and create.

This chapter covers the following:

– Loading ENR data from diskette

– Retrieving ENR data from CD

– Saving the ENR data to the noise figure analyzer’s internal memory

– Copying the ENR data from the diskette to the noise figure analyzer’s internal

memory

The following procedures do not apply to noise sources used with the Keysight
8970A/B Noise Figure Meter.

You must enter ENR values manually into the 8970A/B.

The following procedures do not apply to noise sources with serial prefixes
MY5823

48 Keysight 346A/B/C Operating and Service Manual

Loading ENR Data from Diskette

NOTE

NOTE

To load the ENR data from the diskette and use the data as the current ENR table,
proceed as follows:

1 Power up the noise figure analyzer and wait for the power-up sequence to

complete.

2 Insert the diskette into the floppy drive of the noise figure analyzer.

Do not insert the diskette into the noise figure analyzer until the power-up
sequence is complete.

3 On the noise figure analyzer, press the File key and press the Load menu key to

access the file system.

4 Press the ENR menu key and select whether the ENR table is a Meas Table

(used for measurements) or a Cal Table (used for calibration). If you intend to
use the same ENR table for calibration and measurement, then set the ENR
table as Meas Table.

The noise figure analyzer allows you to use the same or separate ENR tables
for calibration and measurement as required. For more details on specifying

Meas Table and Cal Table, see the Noise Figure Analyzer User’s Guide.

5 Press the Select menu key and use the arrow keys if necessary to highlight

[-A-]. If C: is the currently selected drive use the “..” directory to reach the

A: drive as directed on the screen. Press the Select menu key again to read
the diskette.

Using the ENR Data Diskette or CD 6

6 Use the down arrow key (↓) to highlight the ENR file and press the Enter key to

load it.

When the file is successfully loaded, a message for example, A:A0100364.ENR
file loaded appears on the display.

ENR files with a large number of frequency points (for example, up to 50 GHz)
may take a few seconds to load.

Keysight 346A/B/C Operating and Service Manual 49

6 Using the ENR Data Diskette or CD

Retrieving ENR Data from CD

Noise Source with serial prefixes MY5823 and above are supplied with the noise
source ENR data preloaded on a CD.

The ENR files can be retrieved using computer CD-ROM drive and edited using a
standard text editor.

ENR filename format

The ENR filename of the ENR file stored on the diskette or CD, for example
A0100123.enr, has the following format:

– The first letter shows the noise source type and can be:

– A = 346A

– B = 346B

– C = 346C

– R = R347A

– Q = Q347A

– The next four digits, for example 0100, show the calibration date. For example,

0100 shows a calibration date of January 2000.

–The last three digits, for example 123, are the last three digits of the serial

number of the noise source.

– The file extension is .enr to indicate ENR file format.

Once the ENR file is loaded, to verify that the ENR data is correct, press the ENR
key, then press the ENR Table> menu item to display the ENR table.

50 Keysight 346A/B/C Operating and Service Manual

Using the ENR Data Diskette or CD 6

Confirm that the noise source Serial Number and the noise source Model ID are
correct, and compare the Frequency and ENR values with the supplied Calibration
Sheet or the data printed on the body of the noise source.

Saving the ENR Data to the Noise Figure Analyzer’s Internal Memory

To save the current noise source ENR data from the diskette (A: drive) to the noise
figure analyzer’s internal memory (C: drive), proceed as follows:

1 Load the ENR table as described in “Loading ENR Data from Diskette” on

page 49.

2 Press the File key and press the Save menu key.

3 The ENR menu key indicates whether the file is currently loaded as a

measurement table (Meas Table) or a calibration table (Cal Table). Press the
ENR menu key and select whether you want to store the ENR table as a Meas
Tab le or a Cal Table. If you intend to use the same common ENR table for

calibration and measurement, then set the ENR table as Meas Table.

Keysight 346A/B/C Operating and Service Manual 51

6 Using the ENR Data Diskette or CD

The noise figure analyzer allows you to use the same or separate ENR tables
for calibration and measurement as required. For more details on using ENR
tables, see the Noise Figure Analyzer User’s Guide.

When the ENR table is selected, the Alpha Editor is now presented to you,
allowing you to specify a name for the file. If required you can use the numeric
keypad to enter numbers in the filename. Note that you can also use the
default filename which is in the format of TSTxxxx where x is a sequentially
allocated number. For details of the filename format used for the ENR data
supplied on the diskette, see “ENR filename format” on page 50.

4 Input the name of the ENR table using the Alpha Ed itor and numeric keypad.

Use the Tab key to move to the “..”: field.

5 If the To: Path: field is currently A:, press the Select menu key and use the

arrow key to highlight [-C-], then press the Select menu key again. With the
To: Path: field set to C:, press Enter to save the file with the specified
filename.

When the file is successfully saved, a message for example C:A0100364.ENR
file saved, appears on the status line of the display.

52 Keysight 346A/B/C Operating and Service Manual

Using the ENR Data Diskette or CD 6

NOTE

Copying the ENR Data to the Noise Figure Analyzer’s Internal Memory

To copy the noise source ENR data from the diskette (A: drive) to the noise figure
analyzer’s internal memory (C: drive), proceed as follows:

1 Power up the noise figure analyzer and wait for the power-up sequence to

complete.

2 Insert the diskette into the floppy drive of the noise figure analyzer.

Do not insert the diskette into the noise figure analyzer until the power-up
sequence is complete.

3 Press the File key and press the File Manager menu key.

4 Press the Copy> menu key.

The file system is now presented to you.

5 Press the ENR menu key to set the file type and format to ENR.
6 Set the From: Path: field to A:, use the down arrow key (↓) to highlight the

ENR file and the Select key to select it for copying.

The filename you are going to copy now appears in the From: Name: field.

7 Press the Tab key to navigate to the To: Path: field and ensure it is set to C:.

8 Press the Enter key to copy the selected file from the diskette (A:) to the noise

figure analyzer’s internal memory (C:).

When the file is successfully copied, a message for example A:A0100364.ENR
file copied, appears on the status line of the display.

For details on the ENR filename format, see “ENR filename format” on
page 50.

Keysight 346A/B/C Operating and Service Manual 53

6 Using the ENR Data Diskette or CD

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54 Keysight 346A/B/C Operating and Service Manual

Keysight 346A/B/C Noise Source
Operating and Service Manual

7 ENR File Format

Format Details 56
Examples 61

This chapter explains the format of an ENR file.

55

7 ENR File Format

Format Details

An ENR file:

– includes all data currently supplied on the printed noise source Calibration

– can be viewed and edited using a standard text editor (for example Notepad)

– is simple to create and interpret

– is easily printable

– is easily imported into Excel

The ENR file is read line by line. Each line is terminated by either a linefeed
character, or a carriage-return, linefeed pair. Each line must be less than 100
characters long, excluding the terminator.

Lines containing only whitespace (tab or space character) are ignored. Each line is
interpreted as one of three types of record:

–Comment

– Header Field

–ENR Data

Certificate

Comment records

A comment record must have either a ‘#’ or ‘!’ as the first character in the line. The
entire line is ignored. Comment records can appear at any point within the file.

Header fields

General form

Header fields must have a ‘[’ as the first character in the line. Each header field
has the general form:

– [FieldName OptionalValue]

–The ‘[’ must be the first character on the line.

– The fieldname and optionalvalue, if present, must be separated by whitespace.

– Whitespace following the ‘]’ is ignored.

56 Keysight 346A/B/C Operating and Service Manual

ENR File Format 7

NOTE

– The file must start with one or more header fields (ignoring comments and

blank lines).

All header fields must appear at the beginning of the file before the ENR data
records. Mixing header fields and ENR data is not permitted.

Mandatory header fields

Certain header fields must be present. These are:

Table 7-1 Mandatory header fields

FieldName Description OptionalValue Description Example

Filetype

Version

Indicates the type of
file

Indicates the version of
the file format which
applies to this file

ENR

versionnumber
(formatted as
major.minor)

Only ’ENR’ is allowed
for ENR data files

Allows for future
changes in the file
format.

All mandatory fields must appear in the file before any optional header fields.

Optional header fields

The following header fields are also allowed. Note that only the first two,
Serialnumber and Model are currently used by the noise figure analyzer.

Table 7-2 Optional header fields

FieldName Description OptionalValue Description Example

Serialnumber

Model

The serial number of
the noise source

Identifies the noise
source model
number

serialtext

modelcode Model code string [Model 346B]

A string containing the
serial number

[Serialnumber 3318A14223]

[Filetype ENR]

[Version 1.0]

Keysight 346A/B/C Operating and Service Manual 57

7 ENR File Format

NOTE

Tab le 7-2 Optional header fields (continued)

FieldName Description OptionalValue Description Example

Option

Identifies any model
code option

optioncode Option code string [Option 001]

Caldate

Calduedate

Temperature

Humidity

Date of calibration of
noise source

Indicates date when
next calibration of
noise source is due

Calibration
temperature

Calibration relative
humidity

The format of date&time parameters is YYYYMMDD[.hh:mm:ss], i.e. a 4-digit
year, 2-digit month, and 2-digit date, optionally followed by a ‘.’ then 2-digit
hour ‘:’ 2-digit minutes ‘:’ 2-digit seconds.

Unknown header fields are ignored by the noise figure analyzer. This allows for
future expansion.

ENR data

ENR data records must be ordered from the lowest to the highest frequency.

General form

The noise figure analyzer attempts to interpret lines which are not comments or
header fields as ENR data. ENR data has the general form:

Freq [Funit] ENR [Eunit] [Euncert [on_mag on_phase off_mag
off_phase [Runcert]]]

date&time

date&time

value

value

Formatted date and
optional time

Formatted date and
optional time

Number followed by unit.
Valid units are C, F, K

Number followed by
optional ’%’

[Caldate 19991202.09:15:30]

[Calduedate 20001225]

[Temperature 24C]

[Humidity 40%]

The square brackets denote optional fields.

58 Keysight 346A/B/C Operating and Service Manual

ENR File Format 7

Field separator

Each field is separated by whitespace. A single ‘,’ is allowed within or instead of
the whitespace.

Numeric fields

With the exception of the two optional unit fields, the other fields are numeric.
Numbers are formatted as an optional sign, followed by a sequence of one or
more digits (which can include a single decimal point within the sequence),
followed by an optional exponent. The exponent consists of the ‘e’ or ‘E’ followed
by an optional sign followed by between one and three digits.

Frequency fields

The frequency field (Freq) is the frequency at which the ENR amplitude was
measured.

The frequency unit field (Funit) is optional. The default unit is Hz.

Valid units are Hz, kHz, MHz, GHz, THz. Units are not case sensitive.

ENR fields

The ENR amplitude (ENR) is the measured ENR at the specified frequency.

The ENR unit field (Eunit) is optional. The default unit is dB. Currently, the only
allowed unit is dB. Note that units K, C, F (temperature) are reserved for possible
future use, but are not supported by the noise figure analyzer at this time.

The uncertainty field for the ENR amplitude (Euncert) is optional. However, this
field must be present if reflection coefficient data is supplied.

Reflection coefficient data

The reflection coefficient data is optional and is formatted as four fields
(on_mag, on_phase, off_mag, off_phase):

– reflection magnitude with noise source on

– reflection angle (in degrees) with noise source on

– reflection angle with noise source off

– reflection angle (degrees) with noise source off

Keysight 346A/B/C Operating and Service Manual 59

7 ENR File Format

If any reflection coefficient data is supplied, then all four fields must be present.
Note that the file format requires that the ENR uncertainty field must be present
before any reflection data.

The reflection coefficient uncertainty (Runcert) is an optional parameter.
Reflection coefficient data must be present if this field is supplied.

60 Keysight 346A/B/C Operating and Service Manual

Examples

Example 1

ENR File Format 7

This first example shows a simple ENR file where the Frequency and ENR values
have been entered manually into the noise figure analyzer:

# ENR Data File
# Created by N8973A Keysight NFA Series Noise Figure Analyzer
# Serial Number US00000012 Firmware Revision A.00.01
# 13:37:07 Mar 28, 2000
# Format is: Frequency (Hz), ENR (dB)

[Filetype ENR]
[Version 1.0]
10000000, 15.3500
100000000, 15.4230
1000000000, 15.2280
2000000000, 15.0900
3000000000, 14.9600
4000000000, 14.8400
5000000000, 14.7890
6000000000, 14.7500
7000000000, 14.7720
8000000000, 14.8570
9000000000, 14.9580
10000000000, 15.0600
11000000000, 15.0830
12000000000, 15.1950
13000000000, 15.2710
14000000000, 15.3430
15000000000, 15.4800
16000000000, 15.6750
17000000000, 15.8400
18000000000, 15.8940

Keysight 346A/B/C Operating and Service Manual 61

7 ENR File Format

Example 2

The second example is a typical ENR file supplied on diskette or CD with a noise
source:

[Filetype ENR]
[Version 1.0]
[Serialnumber 3318A15364]
[Model 346B]
[Caldate 20000110.13:53:54]
[Temperature 24C]

62 Keysight 346A/B/C Operating and Service Manual

[Humidity 40%]

! Frequency ENR Unc Refl. Coef. On Refl. Coef. Off
! MHz dB dB Mag Phase Deg Mag Phase Deg

10 MHz 15.281 .193 .0450 -136.0 .0330 -66.0

100 MHz 15.291 .190 .0358 +168.0 .0110 -24.6

1000 MHz 15.118 .151 .0398 +39.6 .0107 +164.5

2000 MHz 14.999 .168 .0377 -85.7 .0266 +.9

3000 MHz 14.879 .172 .0267 +150.6 .0390 -129.2

4000 MHz 14.795 .173 .0130 -18.1 .0313 +106.0

5000 MHz 14.818 .179 .0359 +169.5 .0104 -99.3

6000 MHz 14.846 .181 .0556 +63.7 .0451 +104.3

7000 MHz 14.895 .180 .0430 -37.0 .0579 -2.3

8000 MHz 15.016 .198 .0232 -160.3 .0491 -123.8

9000 MHz 15.134 .201 .0122 +71.4 .0407 +107.3

10000 MHz 15.253 .194 .0080 +116.2 .0248 -15.4

11000 MHz 15.249 .243 .0241 +65.7 .0259 +144.5

12000 MHz 15.349 .240 .0196 +8.8 .0457 +32.2

13000 MHz 15.383 .188 .0217 -5.4 .0362 -61.9

14000 MHz 15.355 .178 .0228 -66.6 .0075 +151.2

15000 MHz 15.367 .187 .0141 +141.6 .0136 -13.2

16000 MHz 15.421 .182 .0251 +6.4 .0030 -127.2

17000 MHz 15.418 .174 .0242 -100.5 .0148 -29.7

18000 MHz 15.464 .179 .0183 +124.4 .0198 -149.1

ENR File Format 7

Keysight 346A/B/C Operating and Service Manual 63

7 ENR File Format

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64 Keysight 346A/B/C Operating and Service Manual

Keysight 346A/B/C Noise Source
Operating and Service Manual

A Caring for Connectors

Introduction 66
Visual Inspection 67
Cleaning 70
Mechanical Inspection: Connector Gages 73
Mechanical Specifications 74
Using Connector Gages 77
Making Connections 80
Adapters 84
Principles of Microwave Connector Care 86

The material contained in this appendix may not apply to the connector you are
using on the instrument.

65

A Caring for Connectors

Introduction

Recent advances in measurement capabilities have made connectors and
connection techniques more important than ever before. Damage to the
connectors on calibration and verification devices, test ports, cables, and other
devices represent an increasing burden in downtime and expense.

This Appendix will help you get the best performance from all coaxial microwave
connectors:

– To know what to look for when cleaning and inspecting them, in order to

preserve their precision and extend their life.

– To make the best possible microwave connections, improving the accuracy

and repeatability of all of your measurements, saving both time and money.

Connector part numbers

Refer to the latest edition of the Keysight RF & Microwave Test Accessories
Catalog for connector part numbers.

Handling and storage

Microwave connectors must be handled carefully, inspected before use and when
not in use, stored in a way that gives them maximum protection. Avoid touching
the connector mating plane surfaces and avoid setting the connectors
contact-end down, especially on a hard surface.

Never store connectors with the contact end exposed. Plastic end caps are
provided with all Keysight connectors and these should be retained after
unpacking and placed over the ends of the connectors whenever they are not in
use. Extend the threads of connectors that have a retractable sleeve or sliding
connector nut, then put the plastic end cap over the end of the connector.

Above all, never store any devices loose in a box or in a desk or a bench drawer.
Careless handling of this kind is the most common cause of connector damage
during storage.

66 Keysight 346A/B/C Operating and Service Manual

Visual Inspection

Visual inspection and, if necessary, cleaning should be done every time a
connection is made.

Metal and metal by-product particles from the connector threads often find their
way onto the mating plane surfaces when a connection is disconnected and even
one connection made with a dirty or damaged connector can damage both
connectors beyond repair.

Magnification is helpful when inspecting connectors, but it is not required and
may actually be misleading. Defects and damage that cannot be seen without
magnification generally have no effect on electrical or mechanical performance.
Magnification is of great use in analyzing the nature and cause of damage and in
cleaning connectors, but it is not required for inspection.

Obvious defects and damage

Examine the connectors first for obvious defects or damage — badly worn plating,
deformed threads or bent, broken, or misaligned center conductors. Connector
nuts should move smoothly and be free of burrs, loose metal particles, and rough
spots.

Immediately discard, or mark for identification and send away for repair, any
connector that has obvious defects like these.

Caring for Connectors A

Mating plane surfaces

Flat contact between the connectors at all points on their mating plane surfaces is
required for a good connection. Therefore, particular attention should be paid to
deep scratches or dents and to dirt and metal or metal by-product particles on
the connector mating plane surfaces.

Also look for bent or rounded edges on the mating plane surfaces of the center
and outer conductors and for any signs of damage due to excessive or uneven
wear or misalignment.

Light burnishing of the mating plane surfaces is normal, and is evident as light
scratches or shallow circular marks distributed more or less uniformly over the
mating plane surface. Other small defects and cosmetic imperfections are also
normal. None of these affect electrical or mechanical performance.

Keysight 346A/B/C Operating and Service Manual 67

A Caring for Connectors

If a connector shows deep scratches or dents, particles clinging to the mating
plane surfaces, or uneven wear, clean it and inspect it again. Damage or defects
like dents or scratches, which are deep enough to displace metal on the mating
plane surface of the connector, may indicate that the connector itself is damaged
and should not be used. Try to determine the cause of the damage before making
further connections.

Precision 7 mm connectors

Precision 7 mm connectors, among them APC-7® connectors, should be
inspected visually with the center conductor collets in place, and whenever the
collet has been removed. See Figure A-1.

The collet itself should be inspected for edge or surface damage and for any signs
that the spring contacts are bent or twisted. If they are, replace the collet. When
the collet has been re-inserted, verify that it springs back immediately when
pressed with a blunt plastic rod or with the rounded plastic handle of the collet
removing tool. Never use a pencil or your finger for this purpose.

Figure A-1 Precision 7 mm connector

68 Keysight 346A/B/C Operating and Service Manual

Sexed connectors

On sexed connectors, especially precision 3.5 mm and SMA connectors, pay
special attention to the female center conductor contact fingers (Figure A-2 and

Figure A-3). These are very easily bent or broken, and damage to them is not

always easy to see. Any connector with damaged contact fingers will not make
good electrical contact and must be replaced.

Caring for Connectors A

Figure A-2 Precision 3.5 mm connectors

Figure A-3 SMA connectors

Keysight 346A/B/C Operating and Service Manual 69

A Caring for Connectors

NOTE

Cleaning

Careful cleaning of all connectors is essential to assure long, reliable connector
life, to prevent accidental damage to connectors, and to obtain maximum
measurement accuracy and repeatability. Yet it is the one step most often
neglected or done improperly. Supplies recommended for cleaning microwave
connectors are as follows:

– Compressed air

–Alcohol

– Cotton swabs

– Lint-free cleaning cloth

Compressed air

Loose particles on the connector mating plane surfaces can usually be removed
with a quick blast of compressed air. This is very easy to do and should always be
tried first using compressed air from a small pressurized can. The stream of air can
be directed exactly where it is wanted through a plastic (not metal) nozzle. No
hoses or other connections are needed. Hold the can upright, to avoid spraying
liquid along with the vapor.

Cleaning alcohol

Dirt and stubborn contaminants that cannot be removed with compressed air can
often be removed with a cotton swab or lint-free cleaning cloth moistened with
alcohol.

Use the least amount of alcohol possible, and avoid wetting any plastic parts in
the connectors with the alcohol.

Alcohol should be used in liquid rather than spray form. If a spray must be used,
always spray the alcohol onto a cloth or swab, never directly into a connector.

Very dirty connectors can be cleaned with pure alcohol. Other solutions that
contain additives should not be used.

70 Keysight 346A/B/C Operating and Service Manual

Carefully avoid wetting the plastic support bead (which is easily damaged by
alcohol) inside the connector and blow the connector dry immediately with a
gentle stream of compressed air.

Precision 7 mm connectors

When precision 7 mm connectors have been cleaned with the center conductor
collet removed, insert the collet and clean the mating plane surfaces again.

When the connector is attached to a small component, or to a cable, calibration,
or verification standard, the easiest way to do this is to put a lint-free cleaning
cloth flat on a table and put a couple of drops of alcohol in the center of the cloth.
It should be noted that it is not necessary to remove the collet to use this cleaning
method.

Retract the connector sleeve threads so that the connector interface is exposed.
Gently press the contact end of the connector into the cloth moistened with
alcohol, then turn the connector.

Dirt on the connector interface will be scrubbed away by the cloth without
damaging the connector. Blow the connector dry with a gentle stream of
compressed air.

This cleaning method can be adapted even for fixed connectors such as those
attached to test ports. Simply fold the cloth into several layers of thickness,
moisten it, press it against the connector interface, and turn it to clean the
connector. Blow the connector dry with a gentle stream of compressed air.

Caring for Connectors A

Cleaning interior surfaces

Interior surfaces, especially on precision 3.5 mm connectors, are very difficult to
reach, and it is easy to damage connectors in trying to clean them. The openings
are very small, and generally the center conductor is supported only at the inner
end, by a plastic dielectric support bead. This makes it very easy to bend or break
the center conductor.

One suitable method (Figure A-4) is to cut off the sharp tip of a round wooden
toothpick, or a smaller diameter wooden rod, and then to wrap it with a single
layer of lint-free cleaning cloth.

Keysight 346A/B/C Operating and Service Manual 71

A Caring for Connectors

NOTE

Figure A-4 Cleaning interior surfaces

Metal must never be used (it will scratch the plated surfaces), and in cleaning
precision 3.5 mm connectors the diameter must not exceed 0.070 in. (1.7 mm).
The wooden handle of a cotton swab, for example, is too large for this purpose.
Even though the handle can sometimes be inserted into the connector, even
when wrapped in lint-free cloth, movement of the handle against the center
conductor can exert enough force on the center conductor to damage it
severely.

Moisten the cloth with a small amount of alcohol and carefully insert it into the
connector to clean the interior surfaces. Use an illuminated magnifying glass or
microscope to see clearly the areas you wish to clean.

Drying connectors

When you have cleaned a connector, always be sure that it is completely dry
before reassembling or using it. Blow the connector dry with a gentle stream of
clean compressed air and inspect it again under a magnifying glass to be sure that
no particles or alcohol residues remain.

72 Keysight 346A/B/C Operating and Service Manual

Mechanical Inspection: Connector Gages

Even a perfectly clean, unused connector can cause problems if it is mechanically
out of specification. Since the critical tolerances in microwave connectors are on
the order of a few ten-thousandths of an inch, using a connector gage is essential.

Before using any connector for the first time, inspect it mechanically using a
connector gage. How often connectors should be gaged after that depends upon
usage.

In general, connectors should be gaged whenever visual inspection or electrical
performance suggests that the connector interface may be out of specification,
for example due to wear or damage. Connectors on calibration and verification
devices should also be gaged whenever they have been used by someone else or
on another system or piece of equipment.

Precision 3.5 mm and SMA connectors should be gaged relatively more often than
other connectors, owing to the ease with which the center pins can be pulled out
of specification during disconnection.

Connectors should also be gaged as a matter of routine — after every 100
connections and disconnections initially, more or less often after that as
experience suggests.

Caring for Connectors A

Connector gage kits containing all of the items required are included in many
Keysight calibration kits. They are also available separately. Part numbers are as
follows:

Table A-1 Recommended connector gages

Type Part number/ordering information

Precision 7 mm (APC-7) 85050-80012

Precision 3.5 mm 11752D

Precision 2.4 mm 11752E

Type-N 85054-60047

Keysight 346A/B/C Operating and Service Manual 73

A Caring for Connectors

Mechanical Specifications

The critical dimension to be measured, regardless of connector type, is the
position (generally, the recession or setback) of the center conductor relative to
the outer conductor mating plane.

Mechanical specifications for connectors specify a maximum distance and a
minimum distance that the center conductor can be positioned behind (or, in
female Type-N connectors, in front of) the outer conductor mating plane. Nominal
specifications for each connector type exist, but the allowable tolerances (and
sometimes the dimensions themselves) differ from manufacturer to manufacturer
and from device to device. Therefore, before gaging any connector, consult the
mechanical specifications provided with the connector or the device itself.

Precision 7 mm connectors

In precision 7 mm connectors, contact between the center conductors is made by
spring-loaded contacts called collets. These protrude slightly in front of the outer
conductor mating plane when the connectors are apart. When the connection is
tightened, the collets are compressed into the same plane as the outer
conductors.

For this reason, two mechanical specifications are generally given for precision
7 mm connectors — the maximum recession of the center conductor behind the
outer conductor mating plane with the center conductor collet removed; and a
minimum and maximum allowable protrusion of the center conductor collet in
front of the outer conductor mating plane with the collet in place.

The center conductor collet should also spring back immediately when pressed
with a blunt plastic rod or with the rounded plastic handle of the collet removing
tool. Never use a pencil or your finger for this purpose.

With the center conductor collet removed, no protrusion of the center conductor
in front of the outer conductor mating plane is allowable, and sometimes a
minimum recession is required. Consult the mechanical specifications provided
with the connector or the device itself.

74 Keysight 346A/B/C Operating and Service Manual

Sexed connectors

NOTE

In Type-N and precision 3.5 mm connectors, the position of the center conductor
in the male connector is defined as the position of the shoulder of the male
contact pin — not the position of the tip. The male contact pin slides into the
female contact fingers and electrical contact is made by the inside surfaces of the
tip of the female contact fingers on the sides of the male contact pin.

50 Ω Type-N connectors

No Type-N connector should ever be used when there is any possibility of
interference between the shoulder of the male contact pin and the tip of the
female contact fingers when the connectors are mated. In practice this means
that no Type-N connector pair should be mated when the separation between
the tip of the female contact fingers and the shoulder of the male contact pin
could be less than zero when the connectors are mated. Gage Type-N
connectors carefully to avoid damage.

Type-N connectors differ from other connector types in that the outer conductor
mating plane is offset from the mating plane of the center conductors. The outer
conductor sleeve in the male connector extends in front of the shoulder of the
male contact pin. When the connection is made, this outer conductor sleeve fits
into a recess in the female outer conductor behind the tip of the female contact
fingers (Figure A-5).

Caring for Connectors A

Figure A-5 Type-N connectors

Keysight 346A/B/C Operating and Service Manual 75

A Caring for Connectors

NOTE

Therefore the mechanical specifications of Type-N connectors give a maximum
protrusion of the female contact fingers in front of the outer conductor mating
plane and a minimum recession of the shoulder of the male contact pin behind the
outer conductor mating plane.

As Type-N connectors wear, the protrusion of the female contact fingers generally
increases, due to wear of the outer conductor mating plane inside the female
connector. This decreases the total center conductor contact separation and
should be monitored carefully.

75 Ω Type-N connectors

75 Ω Type-N connectors differ from 50 Ω Type-N connectors most significantly in
that the center conductor, male contact pin, and female contact hole are smaller.
Therefore, mating a male 50 Ω Type-N connector with a female 75 Ω Type-N
connector will destroy the female 75 Ω connector by spreading the female
contact fingers apart permanently or even breaking them.

If both 75 Ω and 50 Ω Type-N connectors are among those on the devices you
are using, identify the 75 Ω Type-N connectors to be sure that they are never
mated with any 50 Ω Type-N connectors.

76 Keysight 346A/B/C Operating and Service Manual

Using Connector Gages

Before a connector gage is used, it must be inspected, cleaned, and zeroed.

Inspecting and cleaning the gage

Inspect the connector gage and the gage calibration block carefully, exactly as
you have inspected the connector itself. Clean or replace the gage or the block if
necessary (dirt on the gage or block will make the gage measurements of the
connectors inaccurate and can transfer dirt to the connectors themselves,
damaging them during gaging or when the connection is made).

Zeroing the gage

Zero the gage by following the steps described below. Be sure that you are using
the correct connector gage and correct end of the gage calibration block for the
connector being measured.

– Hold the gage by the plunger barrel (not the dial housing or cap) and, for male

connectors, slip the protruding end of the calibration block into the circular
bushing on the connector gage. For precision 7 mm, female precision 3.5 mm
use the flat end of the gage calibration block. For female Type-N connectors,
use the recessed end of calibration block.

– Hold the gage by the plunger barrel only (Figure A-6). Doing so will prevent

errors in gage readings due to the application of stresses to the gage plunger
mechanism through the dial indicator housing.

Caring for Connectors A

– Carefully bring the gage and gage block together, applying only enough

pressure to the gage and gage block to result in the dial indicator pointer
settling at a reading.

– Gently rock the two surfaces together, to make sure that they have come

together flatly. The gage pointer should now line up exactly with the zero mark
on the gage. If it does not, inspect and clean the gage and gage calibration
block again and repeat this process. If the gage pointer still does not line up
with the zero mark on the gage, loosen the dial lock screw and turn the
graduated dial until the gage pointer exactly lines up with zero. Then
re-tighten the lock screw.

Keysight 346A/B/C Operating and Service Manual 77

A Caring for Connectors

NOTE

Figure A-6 Using the connector gage

Gages should be checked often, to make sure that the zero setting has not
changed. Generally, when the gage pointer on a gage that has been zeroed
recently does not line up exactly with the zero mark, the gage or calibration
block needs cleaning. Clean carefully and check the zero setting again.

Measuring connectors

Measuring the recession of the center conductor behind the outer conductor
mating plane in a connector is done in exactly the same way as zeroing the gage,
except of course that the graduated dial is not re-set when the measurement is
made.

If the connector has a retractable sleeve or sliding connector nut — precision
7 mm connectors, for example — extend the sleeve or nut fully. This makes it
easier to keep the gage centered in the connector. Hold the gage by the plunger
barrel and slip the gage into the connector so that the gage plunger rests against
the center conductor. Carefully bring the gage into firm contact with the outer
conductor mating plane.

78 Keysight 346A/B/C Operating and Service Manual

Caring for Connectors A

Apply only enough pressure to the gage so that the gage pointer settles at a
reading.

Gently rock the connector gage within the connector, to make sure that the gage
and the outer conductor have come together flatly. Read the recession (or
protrusion) from the gage dial. (For maximum accuracy, measure the connector
several times and take an average of the readings.)

Rotate the gage relative to the connector between each measurement. To monitor
connector wear, record the readings for each connector over time.

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A Caring for Connectors

Making Connections

Making good connections is easy if a few simple principles are kept in mind:

– All connectors must be undamaged, clean, and within mechanical

specification.

– The connectors must be precisely aligned with one another and in flat physical

contact at all points on the mating plane surfaces.

– The connection must not be too tight or too loose.

– Lateral or horizontal (bending) force must not be applied to the connection,

nor should any connection ever be twisted.

Align connectors carefully

Careful alignment of the connectors is critical in making a good connection, both
to avoid damaging connectors and devices and to assure accurate measurements.

As you bring one connector up to the other and as you make the actual
connection, be alert for any sign that the two connectors are not aligned perfectly.
If you suspect that misalignment has occurred, stop and begin again.

Alignment is especially important in the case of sexed connectors, such as
precision 3.5 mm and SMA connectors, to avoid bending or breaking the contact
pins. The center pin on the male connector must slip concentrically into the
contact fingers of the female connector. This requires great care in aligning the
two connectors before and as they are mated.

When they have been aligned, the center conductors must be pushed straight
together, not twisted or screwed together, and only the connector nut (not the
device itself) should then be rotated to make the connection. (slight resistance is
generally felt as the center conductors mate).

Alignment of precision 7 mm connectors is made easier by the fact that the
connector sleeve on one of the connectors must be extended fully (and the sleeve
on the other connector retracted fully) in order to make the connection. Extending
the sleeve creates a cylinder into which the other connector fits.

If one of the connectors is fixed, as on a test port, extend that connector sleeve
and spin its knurled connector nut to make sure that the threads are fully
extended, while on the other connector, fully retract the connector sleeve.

80 Keysight 346A/B/C Operating and Service Manual

To make a preliminary connection

NOTE

Align the two connectors carefully and engage the connector nut over the
exposed connector sleeve threads on the other connector.

Gently turn the connector nut until a preliminary connection is made. Let the
connector nut pull the two connectors straight together. Do not twist one
connector body into the other (as you might drive a screw or insert a light bulb) as
this is extremely harmful and can damage the connectors.

When the mating plane surfaces make uniform, light contact, the preliminary
connection is tight enough. Do not overtighten this connection.

At this stage all you want is a connection in which the outer conductors make
gentle contact at all points on both mating surfaces. Very light finger pressure
(no more than 2 inch-ounces of torque) is enough.

Final connection using a torque wrench

When the preliminary connection has been made, use a torque wrench to make
the final connection. Tighten the connection only until the “break” point of the
wrench is reached, when the wrench handle gives way at its internal pivot point.
Do not tighten the connection further.

Also make sure that torque actually is being applied to the connection through the
torque wrench, not only to the wrench handle or in any way that prevents the
break point of the wrench from controlling the torque applied to the connection.
Suggestions to ensure that torque is actually being applied are given in Table A -2.

Caring for Connectors A

Using a torque wrench guarantees that the connection will not be too tight, thus
preventing possible damage to the connectors and impaired electrical
performance. It also guarantees that all connections will be made with the same
degree of tightness every time they are made.

Torque wrenches pre-set to the correct value for each connector type are included
in many Keysight calibration kits, and they are also available separately. Torque
settings are detailed in Table A-2.

When using a torque wrench, prevent rotation of anything other than the
connector nut that is being tightened with the torque wrench. Generally this is
easy to do by hand (all the more so if one of the connectors is fixed) as on a test
port. In other situations, an open-end wrench can be used to keep the bodies of
the connectors from turning.

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A Caring for Connectors

Hold the torque wrench lightly by the knurled end of the handle only. Apply force
at the end of the torque wrench only, perpendicular to the wrench and always in a
plane parallel to the outer conductor mating planes. This will result in torque
being applied to the connection through the wrench until the break point of the
wrench is reached.

Avoid pivoting the wrench handle on the thumb or other fingers. This results in an
unknown amount of torque being applied to the connection when the break point
of the wrench is reached. Avoid twisting the head of the wrench relative to the
outer conductor mating plane. This results in applying more than the
recommended torque.

Tab le A-2 Recommended torque settings

Type Description

Precision 7 mm 12 lb-in (136 N-cm)

Precision 3.5 mm 8 lb-in (90 N-cm)

SMA

Type-N

5 lb-in (56 N-cm)

Use the SMA wrench to connect male SMA connectors to female precision

3.5 mm connectors.

Connections of male precision 3.5 mm connectors to female SMA connectors

can be made with the precision 3.5 mm torque wrench (8 lb-in).

Type-N connectors may be connected finger tight. If a torque wrench is used,

12 lb-in (136 N-cm) is recommended.

To reiterate the main do’s and do not’s detailed previously:

– Avoid holding the wrench tightly, in such a way that the handle is not pivoted

but simply pushed downward the same amount throughout its length. If this is
done, an unlimited amount of torque can be applied.

– Hold the wrench at the same point near the end of the handle every time, and

always in the same orientation. Whenever possible, begin tightening the
connection with the wrench held horizontally.

82 Keysight 346A/B/C Operating and Service Manual

Disconnection

NOTE

Disconnect connectors by first loosening the connector nut that was tightened in
order to make the connection. If necessary, use the torque wrench or an open-end
wrench to start the process, but leave the connection finger tight. At all times
support the devices and the connection to avoid putting lateral (bending) force on
the connectors.

Complete the disconnection by disconnecting the connector nut completely.

Never disconnect connectors by twisting one connector or device out of the
other as one might remove a screw or a light bulb. This is extremely harmful and
connector damage can occur whenever the device body rather than the nut
alone is being turned.

If the connection is between sexed connectors, pull the connectors straight apart
and be especially careful not to twist the body of any device as you do so. Twisting
the connection can damage the connector by damaging the center conductors or
the interior component parts to which the connectors themselves are attached. It
can also scrape the plating from the male contact pin or even (in rare instances)
unscrew the male or female contact pin slightly from its interior mounting,
bringing it out of specification (this can also occur if the female contact fingers are
unusually tight).

Caring for Connectors A

Keysight 346A/B/C Operating and Service Manual 83

A Caring for Connectors

CAUTION

Adapters

Adapters are used to connect a device with one connector interface to a device or
to test equipment that has another interface, or to reduce wear on connectors
that may be difficult or expensive to replace. Reducing wear is possibly the most
important use of adapters, especially when devices that have SMA connectors are
being used.

SMA connectors are low-cost connectors generally used up to about 23 GHz.
They are not precision mechanical devices and are not designed for repeated
connections and disconnections as they wear out quickly and are very often
found, upon assembly, to be out of specification, even before they have been
used. This makes them potentially destructive to any precision 3.5 mm connectors
with which they might be mated.

Worn, damaged, or out-of-specification SMA connectors can destroy a
precision 3.5 mm connector even on the very first connection. For this reason
it is recommended that you use high-quality precision adapters, sometimes
called “connector savers”, whenever more than a few connections are to be
made between SMA and precision 3.5 mm connectors.

In most applications two adapters will be required, one each at the input and the
output of the device. Male-female adapters cause no change in the sex of the
interface. The same interface is presented when the adapter is in place as is
presented in the original setup.

Same-sex adapters (male-male, female-female) change the sex of the interface.
For example, if the original interface presents a male connector, attaching a
female-female adapter will result in a female interface to which devices or cables
that have male SMA (or male precision 3.5 mm) connectors can be connected.

Adapters are included in many Keysight calibration kits and with many Keysight
devices, or they may be ordered separately.

84 Keysight 346A/B/C Operating and Service Manual

Table A-3 Adapters

Type Description

– Precision 7 mm/male 3.5 mm

Precision 7 mm and Type-N

Precision 3.5 mm and SMA

– Precision 7 mm/female 3.5 mm
– Precision 7 mm/male 50 Ω Type-N
– Precision 7 mm/female 50 Ω Type-N

– Male 3.5 mm/female 3.5 mm
– Male 3.5 mm/female 3.5 mm
– Female 3.5 mm/female 3.5 mm
– Precision 7 mm/male 3.5 mm
– Precision 7 mm/female 3.5 mm
– “Connector saver” male 3.5 mm/female 3.5 mm
– “Connector saver” male 3.5 mm/male 3.5 mm

Caring for Connectors A

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A Caring for Connectors

Principles of Microwave Connector Care

Tab le A-4 Principles of microwave connector care

Handling and storage

DO DO NOT

– Keep connectors clean. – Touch mating plane surfaces.

– Extend sleeve or connector nut. – Set connectors contact-end down.

– Use plastic end caps during storage.

Visual inspection

DO DO NOT

– Inspect each connector carefully before every

connection.

– Look for metal particles, scratches, and dents.

Cleaning

DO DO NOT

– Try compressed air first. – Use any abrasives.

– Clean connector threads. – Get liquid onto plastic support beads.

Gaging

– Use a damaged connector – EVER.

DO DO NOT

– Clean and zero the gage before using. – Use an out-of-spec connector.

– Use correct gage type.

– Use correct end of calibration block.

– Gage all connectors before first use.

Making connections

DO DO NOT

– Align connectors carefully. – Apply bending force to connection.

– Make preliminary connection lightly. – Overtighten preliminary connection.

– Turn connector nut only to tighten. – Twist or screw in connectors.

– Use a torque wrench for final connection. – Tighten past “break” point of torque wrench.

86 Keysight 346A/B/C Operating and Service Manual

This information is subject to change
without notice. Always refer to the
Keysight website for the latest
revision.

© Keysight Technologies 2001 - 2018
Edition 4, July 26, 2018

Printed in Malaysia

*00346-90148*