OPERATOR MANUAL SERIES 8320 TENULINE® ATTENUATOR Electronic Corporation Cleveland (Solon) Ohio USA ©Copyright 1996 by Bird Electronic Corporation Instruction Book Part Number 920-8320s Rev.
Limited Warranty All products manufactured by Seller are warranted to be free from defects in material and workmanship for a period of one (1) year, unless otherwise specified, from date of shipment and to conform to applicable specifications, drawings, blueprints and/or samples.
Safety Precautions The following are general safety precautions that are not necessarily related to any specific part or procedure and do not necessarily appear elsewhere in this publication. These precautions must be thoroughly understood and apply to all phases of operation and maintenance. Keep Away From Live Circuits Operating personnel must at all times observe general safety precautions. Do not replace components or make adjustments inside test equipment with the high voltage supply turned on.
Bird Model 8320S Tenuline Attenuator Safety Symbols WARNING Warning notes call attention to a procedure, which if not correctly performed, could result in personal injury. CAUTION Caution notes call attention to a procedure, which if not correctly performed, could result in damage to the instrument. The following safety warnings appear in the text where there is danger to operating and maintenance personnel and are repeated here for emphasis.
The following equipment cautions appear in the text whenever the equipment is in danger of damage and are shown here for emphasis. CAUTION The Calorimeter can overheat if operated without sufficient coolant. Failure to keep coolant reservoir adequately filled can result in serious damage to the equipment. CAUTION Use only premixed coolant, Bird part number 6091-120. Use of other solutions will damage the instrument and void all warranties. CAUTION Do not tighten the jack screws with a screwdriver.
About This Manual This instruction book covers the Tenuline Attenuator Models 8321, 8322, 8323 & 8325, which collectively are refered to as the 8320 Series. This instruction book is arranged so that essential information on safety appears in the front of the book. Reading the Safety Precautions Section before operating the equipment is strongly advised. The remainder of this Instruction Book is devided into Chapters and Sections.
Table Of Contents Safety Precautions. . . . . . . . . . . . . . . . . . i Safety Precautions . . . . . . . . . . . . . . . . . . . . . i Warning Statements . . . . . . . . . . . . . . . . . . . . ii Caution Statements . . . . . . . . . . . . . . . . . . . . iii About This Manual . . . . . . . . . . . . . . . . . . . . iv Introduction . . . . . . . . . . . . . . . . . . . . 1 Purpose and Function . . . . . . . . . . . . . . . . . . . 1 Performance Characteristics and Capabilities . . . . . . . . .
Bird Model 8320S Tenuline Attenuator Start-up . . . . . . . . . . . . . . . . . . . . . . . . . 9 Normal Operation . . . . . . . . . . . . . . . . . . . . . 9 Operation Under Abnormal Conditions. . . . . . . . . . . . 10 Shutdown . . . . . . . . . . . . . . . . . . . . . . . . 10 Emergency Shutdown . . . . . . . . . . . . . . . . . . . 10 Maintenance. . . . . . . . . . . . . . . . . . . . 11 Troublshooting . . . . . . . . . . . . . . . . . . . . . . 11 Cleaning . . . . . . . . . . . . . . . . . . . . . .
Reassembly . . . . . . . . . . . . . . . . . . . . . . . 16 Repairs . . . . . . . . . . . . . . . . . . . . . . . . . 16 Shipment . . . . . . . . . . . . . . . . . . . . . . . . 16 Storage . . . . . . . . . . . . . . . . . . . . . . . . .
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Chapter 1 Introduction Purpose and Function The Series 8320 Tenuline Attenuator are low reflection resistance networks for use in reducing RF power in 50 ohm transmission lines by known and controlled amounts. They are self-contained instruments that require no external source of power or utility service. The radiators having cooling fins spaced evenly along their lengths for efficient cooling.
Bird Model 8320S Tenuline Attenuator Tools and Test Equipment 2 Only simple tools such as screwdrivers will be necessary for disassembly of this equipment. A resistance bridge or ohmmeter with an accuracy of one percent or better at 50 ohms is useful for checking the resistance of the RF Section assembly.
Introduction Specifications Impedance 50 ohms nominal VSWR Input Output 1.1:1.0 maximum dc-500 MHz 1.15:1.0 maximum dc-500 MHz Connectors Input Output Bird “QC”, Female N normally supplied Bird “QC”, Female N normally supplied Power Rating Model 8321 Model 8322 Model 8323 Model 8325 50 W 200 W 100 W 500 W Frequency Range DC-500 MHz Attenuation 30 db ± ½ db, dc-500 MHz Calibration Frequencies (to ± 0.
Bird Model 8320S Tenuline Attenuator 4
Chapter 2 Installation Location CAUTION This equipment is designed for operation in a horizontal position only, with the mounting brackets down. Do not operate in any other manner. Allow at least six inches (150 mm) of clearance around the unit, to permit an unimpeded access of convection air currents for adequate heat dissipation. Place the attenuator to permit the shortest possible cable length between the unit and the transmitting equipment.
Bird Model 8320S Tenuline Attenuator WARNING The vent plug must be used at all times when the unit is in operation or cooling. Failure to do this could result in damage to the equipment and endanger the operator’s safety. Be sure to check this plug. Before placing the Model 8325 Attenuator into service, the solid shipping plug, P/N 2450-049 must be removed and replaced by the spring loaded vent plug, P/N 2450-094. The vent hole for this plug is located on the top near the rear.
Chapter 3 Theory of Operation General The Series 8320 Attenuators are symmetrical “T” pads, with the power distribution on the legs being different. The value of the resistance on each leg varies; therefore, according to the power it is to absorb. On the input resistance element, a proportionately larger resistor is of course required for its much greater power dissipation. A “T” configuration is used to provide equal input and output impedances for the 50 ohm transmission line attenuation.
Bird Model 8320S Tenuline Attenuator which are attached to its outer surface. These radiating surfaces dissipate the heat of the coolant into the surrounding air. The Series 8320 may be used for the isolation of power sources up to their maximum power rating and for low level monitoring. The low power value obtained at the output of the attenuator can easily be fed into an oscilloscope or terminated in a small RF load resistor.
Chapter 4 Operating Instructions Use And Function Of Controls Initial Adjustments These attenuators, being passive devices, have no indicators or operating controls. No initial adjustments are necessary other than to connect the attenuator to the RF source and load by means of coaxial cables equipped with suitable matching connector plugs. Start-up CAUTION The input and output ends of these attenuators are clearly labeled. Do not couple an attenuator backwards to the direction of power flow.
Bird Model 8320S Tenuline Attenuator ing procedures or surveillance when the stated performance limits are not exceeded. They should function faultlessly, absorbing and converting the excess RF energy into heat indefinitely, if they are properly maintained and not subjected to an overload. Operation Under Abnormal Conditions The Series 8320 TENULINE® Attenuators are not intended or recommended for outdoor use where they will be unprotected and exposed to the elements.
Chapter 5 Maintenance Troubleshooting PROBLEM Leakage of coolant oil around clamping bands or radiator housing. Excessive overheating of the radiator. High or low DC resistance. POSSIBLE CAUSE Clamping band not tight. Faulty input or output O-Ring. Transmitter power too high. Faulty RF section assembly. Coolant oil level too low. Faulty RF input connector. Loose RF input connector. Faulty RF section assembly. REMEDY Tighten slightly with a screwdriver. Replace Reduce transmitter power.
Bird Model 8320S Tenuline Attenuator sion. Also, occasionally check the coolant level in the radiator tank. Preventive Maintenance If there are signs of coolant leakage around the clamping bands, try tightening them. If the leakage persists, it is likely that the O-Ring seal is damaged or deteriorated. Replace it; see the sections for “coolant and seals” under Disassembly.
Maintenance 2. Pull the connector straight out of its socket. Coolant and Seals To replace or examine the coolant oil, proceed as follows: Models 8321, 8322 and 8323 1. Carefully raise up the back (output connector) end of the attenuator until the unit is resting on its front (input connector) end. 2. Brace the attenuator into a vertical position to avoid tipping it over.
Bird Model 8320S Tenuline Attenuator 5. Now release and remove the clamping band by loosening the 10-32 screw on its clamping block. 6. Remove the domed end cover assembly, P/N 8325-015, which has a special seal busing ring, P/N 2430-089, sealing the attenuator output housing. Be careful when disassembling not to damage either this sealing ring which is fitted on the coolant cylinder housing or the O-Ring, P/N 5-243, on the RF output section.
Maintenance normal operating conditions. As shipped the coolant is at a factory determined level which should approximately fill the entire cylindrical radiator tank. Expansion of the heated coolant is provided for by the expansion reservoir tank. The vent plug allows the release of excess internal pressure. However, the loss of up to 10 percent of the full radiator tank capacity should not impair the operating efficiently of the attenuator.
Bird Model 8320S Tenuline Attenuator 4. The RF section assembly is not subject to further disassembly in the field. A defective unit must be returned to the factory for repair. RF Connector Coolant and Seal To install a new connector, reverse the procedures found in RF Connector, Disassembly. Be sure that the projecting center pin on the connector is carefully engaged and properly seated in the mating socket of the load resistors and then push it firmly home.
Maintenance Replacement Parts List Item 1 Qty. 1 2 1 3 1 4 5 2 6 1 7 2 1 pint (0.31 liter) Description RF section assembly Model 8321 Models 8322/25 Models 8323 Radiator assembly Model 8321 Model 8322 Model 8323 Model 8325 Radiator handle Models 8321/23 Model 8322 Model 8325 RF connectors Clamping band assembly Model 8321 Models 8322/23/25 End cover assembly 8322/23 8325 Dielectric coolant Model 8321 0.7 gallon (2.65 liter) Model 8322 0.35 gallon (1.3 liter) Model 8323 0.9 gallon (3.
Bird Model 8320S Tenuline Attenuator N-Female M-Male HN-Female HN-Male LC-Female LC-Male BNC-Female BNC-Male 18 * Available QC Type Connectors 4240-062 LT-Female 4240-063 LT-Male 4240-268 C-Female 4240-278 C-Male 4240-031 UHF-Female (SO-239) 4240-025 UHF-Male (PL-259) 4250-125 7/8" EIA Air Line 4240-132 4240-018 4240-012 4240-100 4240-110 4240-050 4240-179 4240-002
