Agilent Technologies 281A Service manual

281A/B Adapters
Operating and Service
Manual
Manual part number: 00281-90045
Printed in USA
Print Date: May 2001
Supersedes: October 2000

ii 281A/B Operating And Service Manual
Notice
The information contained in this document is subject to change without
notice.
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shall not be liable for errors contained herein or for incidental or
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Agilent Technologies, Inc.
1400 Fountaingrove Parkway
Santa Rosa, CA 95403-1799, U.S.A.
© Copyright 2000–2001 Agilent Technologies, Inc.

281A/B Operating And Service Manualiii
What You’ll Find In This Manual…
•Overview, page1
•Specifications, page2
•Inspection and Shipping, page3
•Operation, page5
•Replaceable Parts, page7

iv 281A/B Operating And Service Manual
Warranty
Custom systems are warranted by contractual agreement between Agilent
Technologies and the customer.
Certification Agilent Technologies, Inc., certifies that this product met its published
specifications at the time of shipment from the factory. Agilent Technologies
further certifies that its calibration measurements are traceable to the
United States National Institute of Standards and Technology (NIST,
formerly NBS), to the extent allowed by the Institute’s calibration facility,
and to the calibration facilities of other International Standards
Organization members.
Warranty This Agilent Technologies system product is warranted against defects in
materials and workmanship for a period corresponding to the individual
warranty periods of its component products. Instruments are warranted for a
period of one year. During the warranty period, Agilent Technologies will, at
its option, either repair or replace products that prove to be defective.
Warranty service for products installed by Agilent Technologies and certain
other products designated by Agilent Technologies will be performed at
Buyer’s facility at no charge within Agilent Technologies service travel
areas. Outside Agilent Technologies service travel areas, warranty service
will be performed at Buyer’s facility only upon Agilent Technologies’ prior
agreement and Buyer shall pay Agilent Technologies’ round trip travel
expenses. In all other areas, products must be returned to a service facility
designated by Agilent Technologies.
For products returned to Agilent Technologies for warranty service, Buyer
shall prepay shipping charges to Agilent Technologies and Agilent
Technologies shall pay shipping charges to return the product to Buyer.
However, Buyer shall pay all shipping charges, duties, and taxes for products
returned to Agilent Technologies from another country.
Agilent Technologies warrants that its software and firmware designated by
Agilent Technologies for use with an instrument will execute its
programming instructions when properly installed on that instrument.
Agilent Technologies does not warrant that the operation of the instrument,
or software, or firmware will be uninterrupted or error free.
LIMITATION OF WARRANTY. The foregoing warranty shall not apply
to defects resulting from improper or inadequate maintenance by Buyer,
Buyer-supplied software or interfacing, unauthorized modification or
misuse, operation outside of the environmental specifications for the
product, or improper site preparation or maintenance.

281A/B Operating And Service Manualv
NO OTHER WARRANTY IS EXPRESSED OR IMPLIED. AGILENT
TECHNOLOGIES SPECIFICALLY DISCLAIMSTHE IMPLIED
WARRANTIES OR MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE.
EXCLUSIVE REMEDIES. THE REMEDIES PROVIDED HEREIN ARE
BUYER’S SOLE AND EXCLUSIVE REMEDIES. AGILENT
TECHNOLOGIES SHALLNOT BE LIABLE FOR ANY DIRECT,
INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
DAMAGES, WHETHER BASED ON CONTRACT, TORT, OR ANY
OTHER LEGAL THEORY.
YEAR 2000. Agilent Technologieswarrants that eachAgilent Technologies
hardware,software,and firmwareproduct onAgilent Technologies’
Corporate Price List (dated July 1, 1998 or later) delivered under the
product’scontract of sale will be able to accurately process date data
(including, but not limited to, calculating, comparing, and sequencing) from,
into, and between the twentieth and twenty-first centuries, and the years
1999 and 2000, including leap year calculations, when used in accordance
with the product documentation provided that all other products (that is,
hardware,software,firmware) usedincombination with such Agilent
Technologies product(s) properly exchange date data with it.If the
agreement requires that specific Agilent Technologies products must
perform as a system in accordance with the foregoing warranty, then that
warrantywill apply to those Agilent Technologies products as a system, and
Customer retains sole responsibility to ensure the year 2000 readiness of its
information technologyand business environment. The duration of this
warrantyextends through January 31, 2001.
The remedies available under this warranty will be definedin, and subject to,
the terms and limitations of the warranties contained in the contract of sale.
To the extent permitted by local law, this warranty applies only tobranded
Agilent Technologies products and not to products manufacture by others
that may be soldor distributed by Agilent Technologies. Nothing in this
warrantywill be construed to limit any rights or remedies provided
elsewhere in thecontract of sale withrespect tomatters other than year 2000
compliance.
Assistance Product maintenance agreements and other customer assistance agreements
are available for Agilent Technologies products.
For assistance, call your local Agilent Technologies Sales and Service Office
(refer to “Service andSupport” onpagevi).

vi 281A/B Operating And Service Manual
Service and Support
By internet, phone, or fax, get assistance with all your test and measurement needs.
Online assistance: www.agilent.com/find/assist
United States
(tel) 1 800 452 4844 Latin America (tel) [phone]
(fax) [phone]
Canada
(tel) 1 877 894 4414
(fax) [phone]
Europe
(tel) ([phone]
(fax) ([phone]
New Zealand
(tel) 0 800 738 378
(fax) ([phone]
Japan
(tel) ([phone]
(fax) ([phone]
Australia
(tel) 1 800 629 485
(fax) ([phone]
Asia Call Center Numbers
Country Phone Number Fax Number
Singapore 1-800-375-8100 (65) 836-0252
Malaysia 1-800-828-848 1-800-801664
Philippines (632) 8426802
1-800-16510170 (PLDT Subscriber
Only)
(632) 8426809
1-800-16510288 (PLDT
Subscriber Only)
Thailand [phone] (outside Bangkok)
[phone] (within Bangkok) (66) 1-661-3714
Hong Kong 800-930-871 (852) 2506 9233
Taiwan 0800-047-866 (886) 2 25456723
People’s Republic of
China 800-810-0189 (preferred) 10800-650-0021 10800-650-0121
India 1-600-11-2929 000-800-650-1101

281A/B Operating And Service Manual vii
Safety and Regulatory Information
Review this product and related documentation to familiarize yourself with
safety markings and instructions before you operate the instrument. This
product has been designed and tested in accordance with international
standards.
WARNING The WARNING notice denotes a hazard. It calls attention to a procedure,
practice, or the like, that, if not correctly performed or adhered to, could result
in personal injury. Do not proceed beyond a WARNING notice until the
indicated conditions are fully understood and met.
CAUTION The CAUTION notice denotes a hazard. It calls attention to an operating
procedure, practice, or the like, which, 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.
Instrument Markings
When you see this symbol on your instrument, you should refer to the instrument’s
instruction manual for important information.
This symbol indicates hazardous voltages.
The laser radiation symbol is marked on products that have a laser output.
This symbol indicates that the instrument requires alternating current (ac) input.
The CE mark is a registered trademark of the European Community. If it is
accompanied by a year, it indicates the year the design was proven.
The CSA mark is a registered trademark of the Canadian Standards Association.
1SM1-A This text indicates that the instrument is an Industrial Scientific and Medical Group 1
Class A product (CISPER 11, Clause 4).
This symbol indicates that the power line switch is ON.
This symbol indicates that the power line switch is OFF or in STANDBY position.
!

viii 281A/B Operating And Service Manual
Safety Earth
Ground This is a Safety Class I product (provided with a protective earthing
terminal). An uninterruptible safety earth ground must be provided from the
main power source to the product input wiring terminals, power cord, or
supplied power cord set. Whenever it is likely that the protection has been
impaired, the product must be made inoperative and secured against any
unintended operation.
Before Applying Power Verify that the product is configured to match the available main power
source as described in the input power configuration instructions in this
manual. 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.

281A/B Adapters Operating and Service Manual1
Overview
Description Agilent 281 adapters provide a convenient means of couplingbetween
waveguide and coaxial systems. Power can betransmitted in either direction,
and each adapter covers the full frequency range of its waveguide sizewith
an SWR of less than1.30.The flanges are lapped to a slight, controlled
convexity to assure minimum leakage at the waveguide joint. A probe
transforms the waveguide impedance to the 50-ohm impedance of coaxial
line. Complete specifications for the adapters are given inTable1.
Examples of the waveguide flange and coaxial connectors used on these
adapters are shown inFigure 1. One type of flange and two types of coaxial
connectors are used: Type N female connectors (which are compatible with
connectors conformingto MILS-71), are available on all 281A adapters and
Amphenol precision7-mm connectors (available onthe 281B adapters). The
7-mm connector features precise alignment, a clearly definedreference
plane, and low RF leakage. Inaddition, any pair canbe connected together
without an adapter. Option13 adapters have stainless steel Type N female
connectors and are available on the P281B.
Figure 1 Adapters Showing Flange Types and Coaxial Connector Styles

2281A/B Adapters Operating and Service Manual
Specifications
Specifications
Table 1 281A/B Specfications
CAUTION The power that can be handled will be a function of the size of the center
conductor. The majority of the heat flow will be via conduction. The weak
point is the coax portion. The waveguide portion is capable of higher power.
These numbers are assuming an ambient temperature of 25 degrees
centigrade and an altitude of sea level. Higher ambient temperatures and
altitude would degrade power-handling capability.
Model Frequency
Range (GHz)1
1. Maximum Reflection Coefficient: 0.11 (1.25 SWR) over entire frequency range.
Fits Waveguide Size
Nom. OD(in.) EIA Equivalent Flange Coaxial Connector2
2. Typical maximum power handling capability for the Type N and APC-7 connectors is 200 W (refer to caution below).
Length
(in) (mm) Weight (lb) (kg)
X281A 8.20 to 12.40 1 x 1/2 WR90 UG135/U N female 1-7/16 37 1/4 0. 1
P281B 12.40 to 18.00 0.702 -0.391 WR62 UG419/U APC-73
3. Option 013 furnished with stainless steel Type N female connector.
Option 012 furnished with Type N male connector.
Option 006 adds additional alignment holes.
1 26 3/16 0. 1

281A/B Adapters Operating and Service Manual3
Inspection and Shipping
Inspection and Shipping
Inspection
Mechanical Check If external damage to the shipping carton is evident, the carrier’s agent
should be present when the adapter is unpacked. Checkthe adapter for
external damage. If damage is evident, refer to Claims, below, for
recommendedclaim procedure. If theshippingcarton isnot damaged, check
the packaging material for signs of stress that indicate rough handling in
transit. If the adapter appears undamaged, perform the electrical check.
Electrical Check The electrical performance of the adapter should be checked as soon as
possible after receipt against thespecifications showninTable1. If the
adapter does not perform within thespecifications, see thefollowing
paragraphs for recommended claim procedure and repackagingthe
instrument.
Claims If physical damage is evident, or if the adapter does not meet electrical
specifications when received, notify the carrier and the nearest Agilent
Technologies office
Shipping
Using Original Packaging The same containers andmaterial usedin factory packaging can be obtained
through Agilent offices.
If theadapter is being returned to Agilent Technologies for servicing, attach
a tag indicatingthe type of service required, returnaddress, and model
number. Also, mark the container FRAGILEto assurecareful handling
Using Other Packaging The following general instructions shouldbe usedfor repackagingwith
commerciallyavailable materials:
1.Wrap the adapter inheavy paper or plastic. (If shipping to a Agilent
Technologies office or service center, attach a tag indicating the type of
service required, returnaddress, and model number.)
2.Use a strong shipping container. A double-wall carton made of
350-pound test material isadequate.

4281A/B Adapters Operating and Service Manual
Inspection and Shipping
3. Use enough shock-absorbing material (3 to 4-inch layer) around all sides
of the adapter to provide firm cushion and prevent movement inside the
container.
4. Seal the shipping container securely
5. Mark the shipping container FRAGILE to assure careful handling.

281A/B Adapters Operating and Service Manual5
Operation
Operation
Protest Flanges Care should be takentoprotect the face of the flange from any damage that
would prevent close surface-to-surface contact. Any burring,denting, or
scratching will increases RF leakageandthereflection coefficient of the
joint. The supplied plastic cover should be used to protect the flange when
the adapter is not in use.
Assemble Carefully Whenconnecting anadapter to a waveguide.
1.Make sure the rectangular ports are oriented the same way (i.e., not
"cross-guided").
2.Alignports carefully to minimize reflections.
3.Clamp or bolt flanges securely together so that pressure is evenly
distributed over thecontacting surfaces.Loose jointsand flange
distortion result inleakage and mismatch.
Connector Types Type N Connectors
Twoversions of the Type N coaxial connector are usedon the adapters: one
is used on the 281A model, and the other is usedin the Option 13B model.
The version on the 281A model is plated brass andis compatible with
connectors conformingto MIL-C-71. The version on the Option 13B model
is stainless steel and is compatible with connectors conforming to MIL-C-71
or MIL-C-39012. Dimensions of these connectors are given in Figure 2.
Figure 2 Dimensions of Type N Connectors

6281A/B Adapters Operating and Service Manual
Operation
Precision 7 mm Connectors
Except for Option 13, the 281B model adapter has a APC-7 precision 7-mm
coaxial connector. These connectors relyon uniform end-toend contact of
both conductors for electrical continuity. Consequently, the conditionof the
contacting surfaces is critical: they should be kept clean and smooth.To
prevent damagewhen theadapter is not in use,theconnector’sthreaded
sleeve should be fully extended.
Performance Test The maximum SWR for the Adapters are listed in Table1. When making
these measurements, the test results must be less than those listed in Table1
plusthe measurement uncertainty of the measurement system. Measurement
maybe made usinga standard reflectometer setup. To ensure satisfactory
performance, make sure flanges andcoaxial connectors are not damaged or
worn.

281A/B Adapters Operating and Service Manual7
Replaceable Parts
Replaceable Parts
The 281Amay be disassembled for part replacement, but the 281B should
be returned toAgilent because liquid nitrogen andspecial wrenches and
gauges are neededfor assembly.
The explodedview of Figure 3 givesinformationfor ordering replacement
parts and can be used as anassembly guide. Toobtaina replacement part
give the adapter’s full model number and the part number fromTable2, and
addresstheorder tothe nearest Agilent Technologies office.
Figure 3 281A Replacement Parts

8281A/B Adapters Operating and Service Manual
Replaceable Parts
NOTE All 281B adapters should be returned for part replacement.
Table 2 281A Replaceable Parts
Item No. Description Model No. Agilent Part No.
1 RF Connector Body X281A 5020-0213
2 Probe Assembly X281A not applicable
Probe Body1
1. This part is a subcomponent of item number 2 (Probe Assembly for X281A).
00281-20025
Probe Insulator100281-20106
3 Probe Case X281A X281A-5
4 X-band X281A 00281-20017
Flange Cap (not shown)
X-band
P-band X281A P281B 5040-0354 5040-0358