Keithley 7999-4 Service manual

Model 7999-4
Microwa v e Switch
Instruction Manual
Contains Operating and Servicing Information
Keithley Instruments, Inc. warrants this product to be free from defects in material and workmanship for a period of 1 year from date of shipment.
Keithley Instruments, Inc. warrants the following items for 90 days from the date of shipment: probes, cables, rechargeable batter­ies, diskettes, and documentation.
During the warranty period, we will, at our option, either repair or replace any product that proves to be defective.
To exercise this warranty, write or call your local Keithley representativ e, or contact Keithley headquarters in Cleveland, Ohio. Y ou will be given prompt assistance and return instructions. Send the product, transportation prepaid, to the indicated service facility. Repairs will be made and the product returned, transportation prepaid. Repaired or replaced products are warranted for the balance of the original warranty period, or at least 90 days.
LIMITATION OF WARRANTY
This warranty does not apply to defects resulting from product modification without Keithley’s express written consent, or misuse of any product or part. This warranty also does not apply to fuses, software, non-rechargeable batteries, damage from battery leak­age, or problems arising from normal wear or failure to follow instructions.
THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. THE REMEDIES PROVIDED HEREIN ARE BUYER’S SOLE AND EXCLUSIVE REMEDIES.
NEITHER KEITHLEY INSTRUMENTS, INC. NOR ANY OF ITS EMPLOYEES SHALL BE LIABLE FOR ANY DIRECT, INDIRECT, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF ITS INSTRU­MENTS AND SOFTWARE EVEN IF KEITHLEY INSTRUMENTS, INC., HAS BEEN ADVISED IN ADVANCE OF THE POS­SIBILITY OF SUCH DAMAGES. SUCH EXCLUDED DAMAGES SHALL INCLUDE, B UT ARE NOT LIMITED TO: COSTS OF REMOVAL AND INSTALLATION, LOSSES SUSTAINED AS THE RESULT OF INJURY TO ANY PERSON, OR DAM­AGE TO PR OPERTY .
Keithley Instruments, Inc. • 28775 Aurora Road • Cleveland, OH 44139 • 440-248-0400 • Fax: 440-248-6168 • http://www.keithley.com
BELGIUM: Keithley Instruments B.V. Bergensesteenweg 709 • B-1600 Sint-Pieters-Leeuw • 02/363 00 40 • Fax: 02/363 00 64 CHINA: Keithley Instruments China Yuan Chen Xin Building, Room 705 • 12 Yumin Road, Dewai, Madian • Beijing 100029 • 8610-62022886 • Fax: 8610-62022892 FRANCE: Keithley Instruments Sarl B.P. 60 • 3, allée des Garays • 91122 Palaiseau Cédex • 01 64 53 20 20 • Fax: 01 60 11 77 26 GERMANY: Keithley Instruments GmbH Landsberger Strasse 65 • D-82110 Germering • 089/84 93 07-40 • Fax: 089/84 93 07-34 GREAT BRITAIN: Keithley Instruments Ltd INDIA: Keithley Instruments GmbH Flat 2B, WILOCRISSA • 14, Rest House Crescent • Bangalore 560 001 • 91-80-509-1320/21 • Fax: 91-80-509-1322 ITALY: Keithley Instruments s.r.l. Viale S. Gimignano, 38 • 20146 Milano • 02/48 30 30 08 • Fax: 02/48 30 22 74 NETHERLANDS: Keithley Instruments B.V. Postbus 559 • 4200 AN Gorinchem • 0183-635333 • Fax: 0183-630821 SWITZERLAND: Keithley Instruments SA Kriesbachstrasse 4 • 8600 Dübendorf • 01-821 94 44 • Fax: 01-820 30 81 TAIWAN: Keithley Instruments Taiwan 1 Fl. 85 Po Ai Street • Hsinchu, Taiwan, R.O.C. • 886-3572-9077• Fax: 886-3572-9031
The Minster • 58 Portman Road • Reading, Berkshire RG30 1EA • 0118-9 57 56 66 • Fax: 0118-9 59 64 69
6/99
Model 7999-4 SPDT Microwave RS-232 Switch
Instruction Manual
©1999, Keithley Instruments, Inc.
All rights reserved.
Cleveland, Ohio, U.S.A.
Second Printing, December 1999
Document Number: 7999-4-901-01 Rev. B
Manual Print History
The print history shown below lists the printing dates of all Revisions and Addenda created for this manual. The Revision Le vel letter increases alphabetically as the manual under goes sub­sequent updates. Addenda, which are released between Revisions, contain important change in­formation that the user should incorporate immediately into the manual. Addenda are numbered sequentially . When a new Re vision is created, all Addenda associated with the previous Re vision of the manual are incorporated into the new Revision of the manual. Each ne w Revision includes a revised copy of this print history page.
Revision A (Document Number 7999-4-901-01).................................................... September 1999
Revision B (Document Number 7999-4-901-01)..................................................... December 1999
All Keithley product names are trademarks or registered trademarks of Keithley Instruments, Inc. Other brand names are trademarks or registered trademarks of their respective holders.

Safety Precautions

The following safety precautions should be observed before using this product and any associated instrumen­tation. Although some instruments and accessories would normally be used with non-hazardous v oltages, there are situations where hazardous conditions may be present.
This product is intended for use by qualified personnel who recognize shock hazards and are familiar with the safety precautions required to avoid possible injury. Read the operating information carefully before using the product.
The types of product users are:
Responsible body is the individual or group responsible for the use and maintenance of equipment, for ensuring
that the equipment is operated within its specifications and operating limits, and for ensuring that operators are adequately trained.
Operators use the product for its intended function. They must be trained in electrical safety procedures and
proper use of the instrument. They must be protected from electric shock and contact with hazardous live circuits.
Maintenance personnel perform routine procedures on the product to keep it operating, for example, setting
the line voltage or replacing consumable materials. Maintenance procedures are described in the manual. The procedures explicitly state if the operator may perform them. Otherwise, they should be performed only by ser­vice personnel.
Service personnel are trained to work on live circuits, and perform safe installations and repairs of products.
Only properly trained service personnel may perform installation and service procedures. Exercise extreme caution when a shock hazard is present. Lethal voltage may be present on cable connector
jacks or test fixtures. The American National Standards Institute (ANSI) states that a shock hazard e xists when voltage levels greater than 30V RMS, 42.4V peak, or 60VDC are present. A good safety practice is to expect
that hazardous voltage is present in any unknown circuit before measuring.
Users of this product must be protected from electric shock at all times. The responsible body must ensure that users are prevented access and/or insulated from every connection point. In some cases, connections must be exposed to potential human contact. Product users in these circumstances must be trained to protect themselves from the risk of electric shock. If the circuit is capable of operating at or above 1000 volts, no conductive part
of the circuit may be exposed.
As described in the International Electrotechnical Commission (IEC) Standard IEC 664, digital multimeter measuring circuits (e.g., Keithley Models 175A, 199, 2000, 2001, 2002, and 2010) are Installation Category II. All other instruments’ signal terminals are Installation Category I and must not be connected to mains.
Do not connect switching cards directly to unlimited power circuits. They are intended to be used with imped­ance limited sources. NEVER connect switching cards directly to AC mains. When connecting sources to switching cards, install protective devices to limit fault current and voltage to the card.
Before operating an instrument, make sure the line cord is connected to a properly grounded power receptacle. Inspect the connecting cables, test leads, and jumpers for possible wear, cracks, or breaks before each use.
For maximum safety, do not touch the product, test cables, or any other instruments while power is applied to the circuit under test. ALWAYS remove power from the entire test system and discharge any capacitors before: connecting or disconnecting cables or jumpers, installing or removing switching cards, or making internal changes, such as installing or removing jumpers.
Do not touch any object that could provide a current path to the common side of the circuit under test or power line (earth) ground. Always make measurements with dry hands while standing on a dry, insulated surface ca­pable of withstanding the voltage being measured.
The instrument and accessories must be used in accordance with its specifications and operating instructions or the safety of the equipment may be impaired.
Do not exceed the maximum signal levels of the instruments and accessories, as defined in the specifications and operating information, and as shown on the instrument or test fixture panels, or switching card.
When fuses are used in a product, replace with same type and rating for continued protection against fire hazard. Chassis connections must only be used as shield connections for measuring circuits, NOT as safety earth ground
connections. If you are using a test fixture, keep the lid closed while power is applied to the device under test. Safe operation
requires the use of a lid interlock.
If a screw is present, connect it to safety earth ground using the wire recommended in the user documentation.
!
The symbol on an instrument indicates that the user should refer to the operating instructions located in the manual.
The symbol on an instrument shows that it can source or measure 1000 volts or more, including the com­bined effect of normal and common mode voltages. Use standard safety precautions to avoid personal contact with these voltages.
The WARNING heading in a manual explains dangers that might result in personal injury or death. Always read the associated information very carefully before performing the indicated procedure.
The CAUTION heading in a manual explains hazards that could damage the instrument. Such damage may invalidate the warranty.
Instrumentation and accessories shall not be connected to humans. Before performing any maintenance, disconnect the line cord and all test cables.
To maintain protection from electric shock and fire, replacement components in mains circuits, including the power transformer, test leads, and input jacks, must be purchased from Keithley Instruments. Standard fuses, with applicable national safety approvals, may be used if the rating and type are the same. Other components that are not safety related may be purchased from other suppliers as long as they are equivalent to the original component. (Note that selected parts should be purchased only through Keithley Instruments to maintain accu­racy and functionality of the product.) If you are unsure about the applicability of a replacement component, call a Keithley Instruments office for information.
T o clean an instrument, use a damp cloth or mild, water based cleaner . Clean the e xterior of the instrument only . Do not apply cleaner directly to the instrument or allow liquids to enter or spill on the instrument. Products that consist of a circuit board with no case or chassis (e.g., data acquisition board for installation into a computer) should never require cleaning if handled according to instructions. If the board becomes contaminated and op­eration is affected, the board should be returned to the factory for proper cleaning/servicing.
Rev. 2/99
SBG 8/31/99

7999-4 Microwave SPDT RS-232 Switch

CONTACT CONFIGURATION: Single Pole Double Throw. CONNECTOR TYPE: 3-SMA type connectors (COMMON, NO, NC). MAXIMUM SIGNAL: 120W 3GHz (VSWR 1.15 or less), CAT I. CONTACT RESISTANCE: 0.1max. CONTACT LIFE: Mechanical: 5 × 10
6
(at 180cpm).
Electrical: 5 × 10
6
(3GHz, 50, VSWR 1.2 at 20cpm).
MAXIMUM COMMON MODE: 42V peak, any terminal to earth. ACTUATION TIME: 25ms. RELAY CHARACTERISTICS (50):
To 1– 4– 8– 12.4–
Frequency 1GHz 4GHz 8GHz 12.4GHz 18GHz
VSWR (max) 1.1 1.15 1.25 1.35 1.5 Insertion Loss
(dB max.) 0.2 0.2 0.3 0.4 0.5 Isolation
(dB min.) 85 80 70 65 60
GENERAL
INTERFACE: RS-232 control (9600 baud, 8 data, 1 stop). Response
terminator selectable (CR, LF, CRLF, LFCR).
INDICATORS: Power, relay position status. ENVIRONMENT: Operating: 0° to 40°C, up to 35°C <80% RH.
Storage: –25° to 65°C.
EMC: Conforms with European Union Directive 89/336/EEC, FCC
part 15 class B.
SAFETY: Conforms with European Union Directive 73/23/EEC. DIMENSIONS: 109mm long × 112mm wide × 59mm deep (4.3˝ ×
4.4˝ × 2.3˝).
ACCESSORIES SUPPLIED: AC/DC power adapter with line cord,
user and service manual.

T able of Contents

1 General Information
Introduction ................................................................................ 1-2
Feature overview ........................................................................ 1-2
Warranty information ................................................................. 1-2
Manual addenda ......................................................................... 1-2
Safety symbols and terms .......................................................... 1-3
Specifications ............................................................................. 1-3
Unpacking and inspection .......................................................... 1-3
Inspection for damage ......................................................... 1-3
Handling precautions .......................................................... 1-3
Shipment contents ............................................................... 1-4
Instruction manual .............................................................. 1-4
Repacking for shipment ...................................................... 1-4
Connections ................................................................................ 1-4
2 Connections
Introduction ................................................................................ 2-2
Handling precautions ................................................................. 2-2
Configuration ............................................................................. 2-2
Layout ................................................................................. 2-2
Simplified schematic ........................................................... 2-4
Connections ................................................................................ 2-5
RS-232 Connection ............................................................. 2-5
SMA connectors .................................................................. 2-6
Power connector .................................................................. 2-6
3 Operation
Introduction ................................................................................ 3-2
Maximum signal considerations ................................................ 3-2
Toggle relay state switch ............................................................ 3-2
Operation (RS-232) .................................................................... 3-3
Sending and receiving data ................................................. 3-3
Termination characters ........................................................ 3-3
RS-232 Commands ............................................................. 3-5
Switching considerations ........................................................... 3-6
Connector integrity ............................................................. 3-6
Voltage standing wave ratio ................................................ 3-6
Path isolation ....................................................................... 3-6
Insertion loss ....................................................................... 3-7
RFI/EMI .............................................................................. 3-7
4 Service Information
Introduction ................................................................................ 4-2
Handling and cleaning precautions ............................................ 4-2
Handling precautions ........................................................... 4-2
Card and connector cleaning ............................................... 4-2
Performance verification ............................................................. 4-3
Environmental conditions .................................................... 4-3
Recommended equipment ................................................... 4-3
Channel resistance tests ....................................................... 4-3
Replacing components ................................................................ 4-5
Replacement parts ............................................................... 4-5
Replacement precautions ..................................................... 4-5
Soldering considerations ..................................................... 4-5
Disassembly ........................................................................ 4-5
5 Replaceable Parts
Introduction ................................................................................ 5-2
Parts list ...................................................................................... 5-2
Ordering information .................................................................. 5-2
Factory service ............................................................................ 5-2
Component layout ...................................................................... 5-3

List of Illustrations

2 Connections
Figure 2-1 General layout..........................................................................2-3
Figure 2-2 Simplified schematic................................................................2-4
Figure 2-3 RS-232 interface connector .....................................................2-5
3 Operation
Figure 3-1 Toggle relay state switch..........................................................3-2
Figure 3-2 Jumper location........................................................................3-4
4 Service Information
Figure 4-1 Channel resistance test connections.........................................4-4

List of T ables

2 Connections
Table 2-1 RS-232 connector terminals.....................................................2-5
3 Operation
Table 3-1 Jumper positions—termination characters...............................3-3
Table 3-2 Command set............................................................................3-5
4 Service Information
Table 4-1 Recommended verification equipment.....................................4-3
5 Replaceable Parts
Table 5-1 Parts list—electronic components............................................5-3
Table 5-2 Parts list—mechanical parts.....................................................5-4
1

General Information

1-2 General Information

Introduction

This section contains general information about the Model 7999-4 Microwa ve SPDT switch. The information is organized as follows:
Feature overview
Warranty information
Manual addenda
Safety symbols and terms
Specifications
Unpacking and inspection
Connections
If you have any questions after reviewing this information, please contact your local Keithley representative or call one of our Applications Engineers at 1-800-348-3735 (U.S. and Canada only). Worldwide phone numbers are listed at the front of this manual.

Feature overview

The Model 7999-4 is a single channel Microwave SPDT switch with the following features:
SMA connectors
RS-232 relay control
+12V DC power connections
Operating range from DC to 18GHZ

W arranty information

Warranty information is located at the front of this instruction manual. Should your Model 7999-4 require warranty service, contact the Keithley representativ e or authorized repair facility in your area for further information. When returning the switch for repair, be sure to fill out and include the service form at the back of this manual to provide the repair facility with the necessary information.

Manual addenda

Any improvements or changes concerning the switch or manual will be explained in an addendum included with the manual. Be sure to note these changes and incorporate them into the manual.
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