Agilent Technologies 8494A/B, 8495A/B, and 8496A/B Attenuators Operating and Service Manual Agilent Part Number: 08494-90008 Printed in USA Print Date: April 2002 Supersedes: October 2000
Notice The information contained in this document is subject to change without notice. Agilent Technologies makes no warranty of any kind with regard to this material, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose. Agilent Technologies shall not be liable for errors contained herein or for incidental or consequential damages in connection with the furnishing, performance, or use of this material.
What You’ll Find in This Manual… • • • • • • • • “Instrument Definition” on page 1 “Description” on page 2 “Specifications” on page 3 “Installation” on page 6 “Operating Instructions” on page 7 “Operator’s Check” on page 8 “Replaceable Parts” on page 10 “Service” on page 11 Agilent 8494A/B, 8495A/B, 8496A/B Operating And Service Manual iii
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.
Service and Support Any adjustment, maintenance, or repair of this product must be performed by qualified personnel. Contact your customer engineer through your local Agilent Technologies Service Center. You can find a list of local service representatives on the Web at: http://www.agilent.com/find/assist Click on “Contact Us” and select your country.
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.
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. Safety Earth Ground This is a Safety Class I product (provided with a protective earthing terminal).
viii Agilent 8494A/B, 8495A/B, 8496A/B Operating And Service Manual
Instrument Definition This manual contains installation, operation and test information for the Agilent Technologies 8494A/B, 8495A/B, and 8496A/B step attenuators. The instruments covered by this manual have a two-part serial number. The first four digits and letter comprise the serial number prefix. The last five digits form the sequential suffix that is unique to each instrument. The contents of this manual apply to instruments with serial prefixes 2544A and above.
Description Description Agilent 8494A/B, 8495A/B, and 8496A/B are 50-ohm coaxial step attenuators. For the 8494A/B, the attenuation can be varied in 1 dB steps, or 10 dB steps for the 8495A/B and 8496A/B. The attenuation shown on the control knob is the additional attenuation added in the signal path over the insertion loss of the attenuator in the 0 dB position. • Agilent 8494A/B instruments are four-section attenuators with a range of 0 dB to 11 dB in 1 dB steps.
Specifications Specifications Frequency Range and Attenuation Product 8494A 8494B 8495A 8495B 8496A 8496B Frequency Range dc to 4 GHz dc to 18 GHz dc to 4 GHz dc to 18 GHz dc to 4 GHz dc to 18 GHz Attenuation 0 dB to 11 dB 0 dB to 11 dB 0 dB to 70 dB 0 dB to 70 dB 0 dB to 110 dB 0 dB to 110 dB Steps 1 dB 1 dB 10 dB 10 dB 10 dB 10 dB Attenuation Accuracy 8494A/B ( dB): (Referenced from 0 dB) 8495A/B 8496A/B 8494A 8494B 8495A 8495B 8496A 8496B Attenuation Selection (dB)
Specifications Maximum SWR Instrument Frequency Range (GHz) Maximum SWR 8495A dc to 4 1.35 8495B dc to 8 8 to 12.4 12.4 to 18 1.35 1.5 1.7 8494A, 8496A dc to 4 1.5 8494B, 8496B dc to 8 8 to 12.4 12.4 to 18 1.5 1.6 1.9 Maximum Residual Attenuation Attenuation Repeatability RF Power Handling Capability Minimum Life Environment Limits Instrument Maximum Residual Attenuation 8494A, 8494B 0.6 dB + 0.09 dB/GHz 8495A, 8495B 0.4 dB + 0.07 dB/GHz 8496A, 8496B 0.6 d8 + 0.09 dB/GHz 0.
Specifications Physical Characteristics Instrument Dimensions 1 (depth x width x height) Weight 2 8494A/B 6.25 in x 2.875 in x 1.6875 in 159 mm x 73 mm x 43 mm 15 oz 5.125 in x 2.875 in x 1.6875 in 130 mm x 73 mm x 43 mm 11 oz 6.25 in x 2.875 in x 1.6875 in 159 mm x 73 mm x 43 mm 15 oz 8495A/B 8496A/B 425 g 312 g 425 g 1. Dimensions are for general information only. If dimensions are required for building special enclosures, contact your Agilent field engineer. 2.
Installation Installation Initial Inspection Inspect the shipping container for damage. If the shipping container or cushioning material are damaged, they should be kept until the contents of the shipment have been checked for completeness and the instrument has been checked mechanically and electrically. A procedure for checking electrical performance is provided under “Operator’s Check” on page 8 (see also “Performance Tests” on page 9).
Operating Instructions Operating Instructions CAUTION Do not apply power greater than 1 W average, or 100 W peak with a maximum pulse width of 10 microseconds. If these limits are exceeded, the attenuators may be damaged. After the instrument is connected, the attenuation may be selected. Turn counterclockwise to increase attenuation or clockwise to decrease attenuation. Either connector may be used as the input or output. Table 1 lists the attenuator switching order.
Operator’s Check Operator’s Check The operator's check allows the operator to make a quick check of the instrument prior to use or if a failure is suspected. Description The attenuator is driven from a 50-ohm signal source at 1 kHz. The output level from the attenuator is detected by a narrow-bandwidth voltmeter. The attenuator and detector range switches are stepped together and the variations in level noted.
Operator’s Check Table 2 SWR Meter Range (dB) Attenuation and SWR Settings Attenuation (dB) Meter Indication (dB) Minimum Actual Maximum 8494A/B 8495A/B 8496A/B 8494A/B 8495A/B 8496A/B 8494A/B 8495A/B 8496A/B 8494A/B 8495A/B 8496A/B 8494A/B 8495A/B 8496A/B 10 2 0 0 0 - - Set to 0.0 Set to 0.5 - - 10 6 1 10 10 0.40 1.40 - - 0.60 1.60 10 12 2 20 20 0.90 0.30 - - 1.10 0.70 10 16 3 30 30 1.35 1.25 - - 1.65 1.75 10 1 22 4 40 40 1.85 0.
Replaceable Parts Replaceable Parts Table 3 lists the replaceable parts which are the only parts that can be replaced without access to the interior of the instrument. If any parts not listed below need replacement, return the instrument to Agilent Technologies. CAUTION Due to special fixtures necessary for assembly, do not attempt to replace any parts not listed in the table below. If the instrument is opened, the warranty is void.
Service Service Troubleshooting Troubleshooting consists of performing the “Operator’s Check” on page 8. If the instrument does not perform within limits, return the instrument to Agilent Technologies. Repair The only recommended field repair is replacing the outer connector shell for the Option 001 and 003, or replacing the center contact in the 7 mm connector. For any other repair, return the entire instrument to Agilent Technologies.
Service Replacing the Connector Outer Shell NOTE The connector outer shell can be replaced only on the Option 001 (type-N female) or the Option 003 (7 mm). The outer shell on the Option 002 (SMA) cannot be replaced in the field. The connector outer shells on the Option 001 and 003 may be replaced as follows: 1. With a 9/16-inch (1/2-inch for 7 mm) thin open-end wrench, unscrew the outer connector body. 2. Replace the connector outer shell. See Table 3 on page 10 for replaceable parts numbers. 3.
