Agilent Technologies 8494/95/96G/H Attenuators Operating and Service Manual Agilent Part Number: 08495-90025 Printed in USA Print Date: August 2004 Supersedes: July 2002
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… • • • • • • Overview, page 1 Specifications, page 6 Installation, page 10 Operating Instructions, page 12 Replaceable Parts, page 15 Service, page 16 8494/95/96G/H 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 Product maintenance agreements and other customer assistance agreements are available for Agilent Technologies products. 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.
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.
Overview This manual contains operating instructions for the Agilent 8494G/H, 8495G/H, and 8496G/H attenuators. Included in the manual is information required to install and test these attenuators. Specification Instruments Covered by Manual Instrument specifications are indicated in Specifications, page 6. These specifications are the performance standards or limits against which the instruments may be tested. The instruments covered by this manual have a two-part serial number.
Overview NOTE Solenoid (K4) and associated circuitry are not available in models 8495G and 8495H. Figure 1 Typical Four Section Attenuator Schematic Diagram Table 1 and Table 2 on page 3 and Table 3 on page 4 show the typical switching arrangement to increase the amount of attenuation in an 8494G/H, 8495G/H, or 8496G/H in a linear manner. To ensure specified performance, it is recommended that the attenuator sections that are shown in the following tables be used.
Overview Table 1 8494G/H Attenuator Switching Order 8494G/H Attenuator Sections Atten (dB) 1 1 dB 2 2 dB 3 4 dB 4 4 dB 0 1 X 2 X 3 X X 4 X 5 X 6 7 X X X X X X 8 9 X X X X X X X X X X 10 11 Table 2 X X 8495G/H Attenuator Switching Order 8495G/H Attenuator Sections Atten (dB) 1 10 dB 2 20 dB 3 40 dB 0 10 X 20 30 X X X 40 50 X X 60 70 X X X X X X 8494/95/96G/H Operating And Service Manual 3
Overview Table 3 8496G/H Attenuator Switching Order 8496G/H Attenuator Sections Atten (dB) 1 10 dB 2 20 dB 3 40 dB 4 40 dB 0 10 X 20 30 X X X 40 50 X X 60 70 X X X X X X 80 90 X X X X X X X X X X 100 110 X X Each solenoid requires a drive of 20 to 30 V with a switching current of approximately 125 mA* at 24 V dc per section. The solenoid switching time is less than 20 milliseconds including settling time.
Overview Figure 2 CAUTION Instrument Options Typical Solenoid Coil Driver Circuits Do not exceed the RF power rating of 1 W average or 100 W peak with a maximum pulse width of 10 µs. Do not connect an attenuator RF input or output connector to greater the ±7 Vdc. If the attenuator must be connected to a device with a potential greater than ±7 Vdc, use a blocking capacitor. Each instrument is specified with an option number which denotes the configuration of the input and output connectors.
Specifications Specifications Frequency Range and Attenuation Attenuation Accuracy 8494G/H 8495G/H 8496G/H Attenuation Selection (dB) Instrument Frequency Range Attenuation 8494G dc to 4 GHz 0 dB to 11 dB in 1 dB steps 8494H dc to 18 GHz 0 dB to 11 dB in 1 dB steps 8495G dc to 4 GHz 0 dB to 70 dB in 10 dB steps 8495H dc to 18 GHz 0 dB to 70 dB in 10 dB steps 8496G dc to 4 GHz 0 dB to 110 dB in 10 dB steps 8496H dc to 18 GHz 0 dB to 110 dB in 10 dB steps (±dB): (Referenced from 0 d
Specifications Maximum SWR Instrument Frequency Range (GHz) Maximum SWR 8495G dc to 4 1.35 8495H dc to 8 8 to 12.4 12.4 to 18 1.35 1.5 1.7 8494G, 8496G dc to 4 1.5 8494H, 8496H 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 Instrument Maximum Residual Attenuation 8494G, 8494H 0.6 dB + 0.09 dB/GHz 8495G, 8495H 0.4 dB + 0.07 dB/GHz 8496G, 8496H 0.6 d8 + 0.09 dB/GHz ±0.
Specifications Solenoid Cable Connector Section Refer also to Figure 3.
Specifications Minimum Life Switching speed Environment Limits >5 million cycles per section Maximum 20 milliseconds including settling time. The instrument should be stored in a clean, dry environment. The following environmental limits apply to storage and shipment, and operation.
Installation Installation Initial Inspection Inspect the shipping container for damage. If the shipping container or cushioning material is damaged, it 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 given under “Operator’s Check” on page 12 (also see “Performance Tests” on page 14).
Installation Installation Instructions The attenuators may be installed with or without the base. The base is removed by unscrewing the two fillister head screws from the bottom of the base. The attenuator may be mounted without the base by inserting two 4-40 screws into the screw holes in the bottom of the attenuator. Removing the base and mounting the attenuator does not affect the performance of the attenuator.
Operating Instructions Operating Instructions CAUTION Do not apply RF 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. CAUTION Do not ground both solenoid drive pins at the same time. This causes rapid cycling of the solenoid and could reduce the operating life of the attenuator. The rapid cycling may produce a buzzing sound from the attenuator.
Operating Instructions Procedure 1. Connect equipment as shown in Figure 4 on page 12 with the attenuator set to 0 dB attenuation. 2. Set the test oscillator to 0.3 Vrms at 1 kHz. 3. Set SWR meter range to 2 dB (expanded) [or for the 8494G/H to 10 dB (expanded)] and adjust its bandwidth to center of adjustment range. Fine tune oscillator frequency to obtain maximum meter indication. 4. Set attenuator and SWR meter range switch as listed in Table 4 and verify that SWR meter indicates within limits shown.
Operating Instructions Performance Tests The instrument can be tested to the accuracy of the “Specifications” on page 6, with an automatic network analyzer or equivalent equipment of suitable accuracy. If an automatic network analyzer is available, test the instrument using the procedures in the analyzer's operating manual. Refer to the Agilent 11713A Attenuator/Switch Driver Operating and Service Manual for programming instructions.
Replaceable Parts Replaceable Parts Table 5 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. To order a part listed in the replaceable parts table below, quote the part number, indicate the quantity required, and address the order to the nearest Agilent Technologies office.
Service Service Troubleshooting Troubleshooting consists of performing the “Operator’s Check” on page 12. 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 4. Close the gap between coupling nut with the nut on the extended-sleeve connector. To disconnect: 1. Loosen the coupling nut of the connector showing the wider gold band. CAUTION Part the connectors carefully to prevent striking the inner conductor contact. To care for the device: 1. Keep contacting surfaces smooth and clean. Irregularities and foreign particles can degrade electrical performance. 2.
Service CAUTION Do not use aromatic or chlorinated hydrocarbons, esters, ethers, terpenes, higher alcohols, ketones, or ether-alcohols such as benzene, toluene, turpentine, dioxane, gasoline, cellosolve acetate, or carbon tetrachloride. Keep exposure of the connector parts to both the cleaning fluid and its vapors as brief as possible. Replacing Amphenol 7 mm Center Contact CAUTION Through wear or damage, the contact in the 7 mm center conductor may need replacement.
Service 3. Allow the jaws of the tool used to close and pull straight back from the connector without twisting. The contact should come with the tool. If not, repeat the process. Do not reuse the contact. 4. Snap in a new contact by pushing it in place. Test the action of the new contact by pushing it in. It should spring out again when released. Type N Connector Dimensions Figure 7 For critical dimensions for the type-N connector, see below.
