Agilent Technologies 87075C Option H08 Manual

Agilent Technologies
87075C Option H08
User’s and Service Guide

Agilent Technologies
87075C Option H08
User’s and Service Guide
This Guide applies to 87075C instruments
with serial numbers greater than US37370245
Use this manual with the following documents:
87050E/75C User’s Guide
Part Number 87050-90026
and
87050E/75C Addendum
Part number 87075-90021
Manufacturing Part Number: 87075-90022
Printed in USA
July 2005
© Copyright 2003, 2005 Agilent Technologies, Inc. All rights reserved.

2User’s and Service Guide Supplement
Warranty Statement
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, AGILENT 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. AGILENT SHALL NOT BE LIABLE FOR ERRORS OR FOR INCIDENTAL
OR CONSEQUENTIAL DAMAGES IN CONNECTION WITH THE FURNISHING, USE, OR
PERFORMANCE OF THIS DOCUMENT OR ANY INFORMATION CONTAINED HEREIN.
SHOULD AGILENT 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 WILL
CONTROL.
Definitions
•Specifications describe the performance of parameters covered by the product warranty
(temperature - 0 to 55 °C, unless otherwise noted.)
•Typical describes additional product performance information that is not covered by the
product warranty. It is performance beyond specification that 80% of the units exhibit
with a 95% confidence level over the temperature range 20 to 30 °C. Typical
performance does not include measurement uncertainty.
•Nominal values indicate expected performance, or describe product performance that is
useful in the application of the product, but is not covered by the product warranty.

User’s and Service Guide Supplement 3
Safety Notes
The following safety notes are used throughout this manual. Familiarize yourself with
each of the notes and its meaning before operating this instrument. All pertinent safety
notes for using this product are located in Chapter 5, “Safety and Regulatory Information,”
on page 60.
WARNING Warning denotes a hazard. It calls attention to a procedure which, if
not correctly performed or adhered to, could result in injury or loss
of life. Do not proceed beyond a warning note until the indicated
conditions are fully understood and met.
CAUTION Caution denotes a hazard. It calls attention to a procedure that, if not
correctly performed or adhered to, could result in damage to or destruction of
the instrument. Do not proceed beyond a caution sign until the indicated
conditions are fully understood and met.
DFARS/Restricted Rights Notice
If software is for use in the performance of a U.S. Government prime contract or
subcontract, Software is delivered and licensed as “Commercial computer software” as
defined in DFAR 252.227-7014 (June 1995), or as a “commercial item” as defined in FAR
2.101(a) or as “Restricted computer software” as defined in FAR 52.227-19 (June 1987) or
any equivalent agency regulation or contract clause. Use, duplication or disclosure of
Software is subject to Agilent Technologies’ standard commercial license terms, and
non-DOD Departments and Agencies of the U.S. Government will receive no greater than
Restricted Rights as defined in FAR 52.227-19(c)(1-2) (June 1987). U.S. Government users
will receive no greater than Limited Rights as defined in FAR 52.227-14 (June 1987) or
DFAR 252.227-7015 (b)(2) (November 1995), as applicable in any technical data.

4User’s and Service Guide Supplement

Contents
5
1. General Information
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Verify the Shipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Specifications and Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Environmental . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Preparations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Environmental . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Electrostatic Discharge Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Connecting and Turning On the Test Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Setting the Test Set Address Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Performing the Operator’s Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Equipment Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2. Controlling the Test Set and Making Measurements
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Control Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Computer Control via Network Analyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Direct Computer Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Manual Control via Network Analyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Calibrating the Test System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Making Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3. Front/Rear Panel
Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Line Power Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Ports 1—8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
The REFLECTION Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
The TRANSMISSION Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
The GROUND Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
The PORT CONNECTION Status LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Rear Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
The Parallel Port Input Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
The 871X Printer Parallel Port Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
GPIB Connector (Agilent 8753D/E only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Address Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Line Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

6
Contents
Power Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
4. Service
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
Performance Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
Equipment Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
Insertion Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
Return Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
Isolation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
Performance Test Record . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
Replaceable Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
General Troubleshooting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
Troubleshooting Power Supply Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
Troubleshooting the Front Panel Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
Troubleshooting the Controller and Switch Driver Boards . . . . . . . . . . . . . . . . . . . . . . . .53
Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
System Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
A1 Power Supply Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
A2 Front Panel Display Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
A3 Main Switch Board Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
A4 Controller Board Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56
Connector Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
5. Safety and Regulatory Information
Safety and Regulatory Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
Connector Care and Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
Before Applying Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
Shipping Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61
Cautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62
Instrument Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63
Contacting Agilent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64

7
1General Information

8Chapter 1
General Information
Description
Description
The Agilent 87075C Option H08 Multiport Test Set is designed for use
with Agilent 75Ωnetwork analyzers, such as the 8753C/D/E, 8711B/C,
8712B/C, 8713B/C, and 8714B/C.
The multiport test set provides the ability to make single connection,
multiple measurements of multiport devices. Throughput is increased
by reducing the number of device reconnects the operator must
perform. Switching is performed with solid-state switches; no
mechanical parts are used.
The test set can be controlled with the network analyzer’s internal
IBASIC capability (if available), an external GPIB controller, or parallel
control.
NOTE This User's and Service Guide documents the use of the test set with an
Agilent 8753D/E Option 075 only.
When necessary, part numbers will be provided in parentheses after the
description of a part for clarification. Example: “Use any two Type-N
75 Ωjumper cables (8120-6995)....”

Chapter 1 9
General Information
Verify the Shipment
Verify the Shipment
After the test set has been unpacked, keep the original packaging
materials so they can be used if you need to transport the instrument.
Verify that you have received the items listed below in Table 1-1.
Inspect the test set and all accessories for any signs of damage that may
have occurred during shipment. If your test set or any accessories
appear to be damaged or missing, refer to “Contacting Agilent” on page
64.
Table 1-1 87075C Option H08 Accessories Supplied
Description Part Number Quantity
Power Cord See Figure 3-3 on page 42 1
Front Handle Kit 5063-9227 1
Parallel Port Interface Cable 8120-6818 1
Type-N to Type-N Cable 75 Ω8120-8624 2
Type-N Semi-Rigid Jumper Cables
10 inch, 75 Ω
8120-6983 2
Cal Constant Disk for Agilent 871x
Self-Cal
08712-10016 1
Adapter (APC-7 to Type-N) 85054-60001 2
Disk (Sample Program) 87075-10004 1
Cable Assembly-Test Port 87075-60026 1
Cable Assembly-Test Port 87075-60028 1
87050E / 87075C User’s and Service
Guide
87050-90026 1
Addendum to 87075C Option H08
User’s and Service Guide
87075-90021 1
87075C Option H08 User’s and
Service Guide
87075-90022 1

10 Chapter 1
General Information
Specifications and Characteristics
Specifications and Characteristics
Table 1-2 87075C Option H08 Performance Specifications
Parameter Specification
Frequency Range 3 MHz to 1.3 GHz
Isolationa
a. Between any two non-connected signal paths
>60 dB
Return Lossb
b. When properly terminated in 75 Ω
>15 dB
Insertion Loss <6 dBc, <10 dBd
c. From any test port to the Reflection port
d. From any test port to the Transmission port
Input Power Damage Level >+16 dBm

Chapter 1 11
General Information
Requirements
Requirements
Electrical
The alternating-current (AC) power that is supplied to the test set
must meet the following requirements:
Voltage: 90 to 250 Vac
Frequency: 48 to 66 Hz
Available power: 40 watts minimum
If the available AC line voltage is outside the 90 to 250 Vac range, an
autotransformer that provides third wire continuity to earth ground
may be used.
Environmental
Operating Environment
Indoor use only
Operating temperature: 0 to 55 °C
Maximum relative humidity: 80 percent for temperatures up to 31 °C
decreasing linearly to 50 percent relative humidity at 40 °C
Altitude: up to 15,000 feet (4,572 meters)
Enclosure protection: IP 20, according to IEC 529
CAUTION This product is designed for use in INSTALLATION CATEGORY II,
and POLLUTION DEGREE 2, per IEC 101 and 664 respectively.
Non-Operating Storage Conditions
Temperature: –40 °C to +70 °C
Humidity: 0 to 90 percent relative at +65 °C (non-condensing)
Altitude: 0 to 15,240 meters (50,000 feet)
Weight
Net: Approximately 7 kg
Shipping: Approximately 20 kg

12 Chapter 1
General Information
Requirements
Cabinet Dimensions
These dimensions exclude front and rear panel protrusions.
132.8 mm H by 425.0mm W by 497.0 mm L
(5.23 in by 16.75 in by 19.60 in)
Figure 1-1 Physical Dimensions
87075C Option H08 Options
UK6
Option UK6 provides a test data package for all critical specifications. A
calibration and test data package is shipped with the test set when the
UK6 Option is selected.

Chapter 1 13
General Information
Preparations
Preparations
Electrical
1. Ensure that the “Requirements” on page 11 are met.
2. Verify that the power cable is not damaged and that the power
source outlet provides a protective earth ground contact. Note that
Figure 1-2 depicts only one type of power source outlet. Refer to
Figure 3-3 on page 42 to see the different types of power cord plugs
that can be used with your test set.
Cables are available in different lengths. For descriptions and part
numbers of cables other than those described in Figure 3-3, Refer to
“Contacting Agilent” on page 64.
3. If this product is to be powered by autotransformer, make sure the
common terminal is connected to the neutral (grounded) side of the
ac power supply.
Figure 1-2 Protective Earth Ground
WARNING This is a Safety Class I product (provided with a protective
earthing ground incorporated in the power cord). The mains
plug shall only be inserted into a socket outlet provided with a
protective earth contact. Any interruption of the protective
conductor, inside or outside the instrument, is likely to make
the instrument dangerous. Intentional interruption of the
protective conductor is prohibited.

14 Chapter 1
General Information
Preparations
Environmental
1. Ensure that the “Requirements” on page 11 are met.
2. If you are installing the test set into a cabinet, ensure there are at
least two inches of clearance around the sides and back of the test
set and the system cabinet. See Figure 1-3. The convection into and
out of the test set must not be restricted. The ambient temperature
(outside the cabinet) must be less than the maximum operating
temperature of the test set by 4 ×C for every 100 watts dissipated in
the cabinet.
Figure 1-3 Ventilation Clearance Requirements
CAUTION If the total power dissipated in the cabinet is greater than 800 watts,
forced convection must be used.

Chapter 1 15
General Information
Preparations
Electrostatic Discharge Protection
Protection against electrostatic discharge (ESD) is essential while
removing or connecting cables or assemblies within the network
analyzer or test set.
Static electricity can build up on your body and can easily damage
sensitive internal circuit elements when discharged. Static discharges
too small to be felt can cause permanent damage. To prevent damage to
the instruments:
•always wear a grounded wrist strap having a 1 MΩresistor in series
with it when handling components and assemblies.
•always use a grounded, conductive table mat while working on the
instrument.
•always wear a heel strap when working in an area with a conductive
floor. If you are uncertain about the conductivity of your floor, wear a
heel strap.
Figure 1-4 shows a typical ESD protection setup using a grounded mat
and wrist strap.
Figure 1-4 ESD Protection Setup

16 Chapter 1
General Information
Getting Started
Getting Started
Connecting and Turning On the Test Set
The 87075C Option H08 test set is designed to be placed underneath
the network analyzer, in a rack system or on a bench top, and connected
as shown in Figure 1-5. Use the two Type N 75 Ωjumper cables (Agilent
Part No. 8120-6983) that were shipped with the test set. See Table 1-1
on page 9 for a list of accessories supplied.
Figure 1-5 Connecting the Test Set to the Network Analyzer
CAUTION Never connect 50 Ωcables to the test set or network analyzer.
Otherwise, connector damage will occur.
After the proper front and rear panel connections have been made, turn
On the test set using the front panel line switch. The front panel line
switch disconnects the mains circuits from the mains supply after the
EMI filters and before other parts of the instrument.
CAUTION For accurate, repeatable measurements, be sure to let the test set warm
up for at least two hours. It is recommended that the test set not be
turned Off on a regular basis. For the most stable and accurate
measurements, leave the test set turned On at all times.

Chapter 1 17
General Information
Setting the Test Set Address Switch
Setting the Test Set Address Switch
The test set is shipped with the GPIB address set to 12, which sets the
parallel address to 00 as in Figure 1-6. The left most switch is also
shown in the up, or “On”, position which is required for operation with
the Agilent 8753 series network analyzer or GPIB operation of the test
set. Refer to Chapter 2, “Controlling the Test Set and Making
Measurements,” on page 21, for the definition of the parallel address.
To set the parallel address use only the number 1 and 2 switches. The
possibilities for parallel port addressing are an address of 0, 1, 2, or 3.
When GPIB is used, the parallel address is ignored.
Figure 1-6 The Test Set Address Switch
CAUTION Make sure the test set is turned Off before you change the position of
any address switch.
NOTE The left most switch is used to specify whether the test set will work
with an Agilent 8753D/E or an Agilent 871xC. When the switch is up,
the test set will work with an Agilent 8753D/E and behaves as indicated
in Chapter 3. When the switch is down, the test set will work with an
Agilent 871xC. Refer to the 87075C User’s and Service Guide (Agilent
Part No. 87075-90005) for operating instructions.
The last switch is used to specify whether the test set will work with an
8753ET/ES or an 8712/14ET/ES. When the switch is up, the test set will
work with an 8753ET/ES and behaves as indicated in Chapter 2,
“Controlling the Test Set and Making Measurements.” When the switch
is down, the test set will work with 8712/14ET/ES. Refer to the
standard 87050E/75C User’s and Service Guide (87050-90026) for
operating instructions.

18 Chapter 1
General Information
Performing the Operator’s Check
Performing the Operator’s Check
The following operator’s check is designed to provide you with a high
degree of confidence that your test set is working properly. It is not
designed to verify specifications. To verify specifications, refer to
Chapter 4, “Service,” on page 43. In the event that your test set is not
working properly, it must be returned to Agilent for servicing. Contact
the nearest sales or service office for instructions on returning the test
set to Agilent. See “Contacting Agilent” on page 64.
For information on how to control the test set, refer to page 21.
Equipment Required
• Network Analyzer, 75 Ωimpedance (8753D/E)
• Computer (Agilent 9000 series 200/300/700)
• “CONTROL” program.
• Cable, 75 Ω, Type N, (8120-2408 or equivalent)
• Calibration Kit, 75 Ω, Type N (85036B)
Procedure
This procedure is for performing a simple operator’s check using a
network analyzer of the proper frequency range and impedance.
1. Connect the 75 Ωcable to the Reflection port of the analyzer.
2. Perform a one-port reflection calibration at the end of the 75 Ωcable
over the frequency range of 3 MHz to 1.3 GHz on the analyzer. Verify
that the calibration is active and that a cable terminated with a
short displays a return loss of 0 dB ±0.2 dB.
3. Connect the cable (already connected to the Reflection port of the
analyzer) to the Reflection port of the 87075C Option H08 test set.
4. Measure the return loss of each path of the test set by selecting
Ports 1 through 12, one at a time, viewing the display on the network
analyzer. All eight ports should be either unterminated or shorted.
5. The return loss value should be a maximum of 14 dB. This accounts
for the maximum of 6 dB loss each way, plus a 2 dB margin of error
to account for source match errors. Typically the return loss for each
port will be about 4 dB to 8 dB, depending upon frequency, and all
ports should look approximately the same.
6. Better accuracy can be obtained by averaging two measurements:
one taken with a short attached and one taken with an open
attached.