INSTRUCTION BOOK TERMALINE® LOAD RESISTOR SERIES 8745/8746 Bird® Electronic Corporation 30303 Aurora Road Cleveland (Solon), Ohio 44139 Sales & Technical Support: 440-248-1200 866-695-4569 toll free Sales email: sales@bird-technologies.com Technical Support email: atechapp@bird-technologies.com ©Copyright 2010 by Bird Electronic Corporation Instruction Book Part Number 920-8745/46 Rev.
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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. WARNING Keep Away From Live Circuits Operating Personnel must at all times observe general safety precautions.
This symbol indicates that a shock hazard exists if the precautions in the instruction manual are not followed. The caution symbol appears on the equipment indicating there is important information in the instruction manual regarding that particular area. This symbol indicates that the unit radiates heat and should not be touched while hot.
Safety Statements USAGE ANY USE OF THIS INSTRUMENT IN A MANNER NOT SPECIFIED BY THE MANUFACTURER MAY IMPAIR THE INSTRUMENT’S SAFETY PROTECTION. USO EL USO DE ESTE INSTRUMENTO DE MANERA NO ESPECIFICADA POR EL FABRICANTE, PUEDE ANULAR LA PROTECCIÓN DE SEGURIDAD DEL INSTRUMENTO. BENUTZUNG WIRD DAS GERÄT AUF ANDERE WEISE VERWENDET ALS VOM HERSTELLER BESCHRIEBEN, KANN DIE GERÄTESICHERHEIT BEEINTRÄCHTIGT WERDEN.
SERVICE SERVICING INSTRUCTIONS ARE FOR USE BY SERVICE - TRAINED PERSONNEL ONLY. TO AVOID DANGEROUS ELECTRIC SHOCK, DO NOT PERFORM ANY SERVICING UNLESS QUALIFIED TO DO SO. SERVICIO LAS INSTRUCCIONES DE SERVICIO SON PARA USO EXCLUSIVO DEL PERSONAL DE SERVICIO CAPACITADO. PARA EVITAR EL PELIGRO DE DESCARGAS ELÉCTRICAS, NO REALICE NINGÚN SERVICIO A MENOS QUE ESTÉ CAPACITADO PARA HACERIO. WARTUNG ANWEISUNGEN FÜR DIE WARTUNG DES GERÄTES GELTEN NUR FÜR GESCHULTES FACHPERSONAL.
CONNECT INTERLOCK TO TRANSMITTER BEFORE OPERATING. BRANCHER LE VERROUILLAGE À L'ÉMETTEUR AVANT EMPLOI. CONECTE EL INTERBLOQUEO AL TRANSMISOR ANTES DE LA OPERACION. VOR INBETRIEBNAHME VERRIEGELUNG AM SENDER ANSCHLIESSEN. PRIMA DI METTERE IN FUNZIONE L'APPARECCHIO, COLLEGARE IL DISPOSITIVO DI BLOCCO AL TRASMETTITORE.
About This Manual This manual covers the operating and maintenance instructions for the following models 8745 8746 Changes to this Manual We have made every effort to ensure this manual is accurate. If you discover any errors, or if you have suggestions for improving this manual, please send your comments to our Solon, Ohio factory. This manual may be periodically updated. When inquiring about updates to this manual refer to the part number and revision on the title page.
Table of Contents Safety Precautions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i Safety Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i Warning Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii Caution Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii Safety Statements . . . . . .
Additional Repairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Storing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Shipping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Customer Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Specifications . . . . . . . . . .
Chapter 1 Introduction The Model 8745/46 Termaline Load Resistor is designed as a compact, lowreflection, and non-radiating termination for RF transmission lines. Cooled by internal water flow, it generates almost no surface heat, making installation space minimal and convenient. The load can safely dissipate up to 20 kilowatts of continuous power when used in a 50 ohm coaxial transmission line system.
Introduction 2
Chapter 2 Theory of Operation General This load resistor utilizes an external water supply for the direct cooling of the resistor element. By using this technique, the need for an intermediate dielectric fluid to transfer the heat generated in the resistor element has been eliminated, reducing the physical size of the load to a virtual minimum. This simplified system allows the use of the loads in more varied environments, and attachment in any orientation.
Theory of Operation Cooling Water The electrical performance of these RF loads is affected by impurities or other chemical additives in the cooling water. The presence of salts in the water definitely makes the device unusable because salts cause a rapid increase in VSWR. Therefore, sea water or silty water should not be used for cooling the loads.
Chapter 3 Installation Load Resistor Connection The compact design of the Models 8745/46 Termaline Load Resistor enables it to be installed in very small spaces. It requires no ventilation and may be placed at any attitude. Do not install it where the load may be subjected to severe vibration or to physical shock. The load is ready for connection as received from the factory.
Installation Flow Switch (Optional) The ports of the flow switch are 3/4 inch NPT Female. The direction of flow is marked on the casting of the flow tube and on the operating head. Observe carefully- opposite connection will restrict the water flow and cause load failure. The flow switch may be connected to the inlet or the outlet side of the load, preferably as close to the load as possible. Just be certain the flow through the switch is in the correct direction.
Chapter 4 Operating Instructions General CAUTION DO NOT disconnect the water flow switch leads from the control assembly. Any operation of the load without a properly functioning cooling system will cause almost immediate destruction of the resistor element. WARNING Never attempt to disconnect the equipment from the transmission line while RF power is being applied. Leaking RF energy is a potential health hazard. The Models 8745/46 Termaline Load Resistors do not have any operating controls.
Operating Instructions Operating as an RF Wattmeter The RF load can be combined with a Bird Rigid Line Series Thruline Wattmeter to form an absorption-type wattmeter by inserting the wattmeter line section just ahead of the RF load. Installation and operation of the wattmeter is covered in the Thruline Wattmeter Instruction Book. Note: Select a wattmeter type appropriate to the input connector of the load resistor. Consult the Bird Catalog or contact the Company. 1.
Chapter 5 Maintenance General WARNING Never attempt to disconnect the equipment from the transmission line while RF power is being supplied. Leaking RF energy is a potential health hazard. The Models 8745/46 Termaline Load Resistors are rugged and simple, requiring only nominal and routine attention. The load is designed to operate satisfactorily for long periods of time if care is taken not to exceed its power handling capabilities.
Maintenance Preventative Maintenance Due to the basic simplicity of construction, the major requirement for preventive maintenance is to keep the equipment clean. RF Load Resistor Preparation: z z z z Tools: Common hand tools Ohmmeter with an accuracy of ± 1% at 50 ohms. Use low resistance leads, preferably a short piece of 50 ohm coaxial cable fitted with alligator clips.
Termaline Load Resistor 8745/8746 Replacing a Resistive Element This series of water-cooled loads is designed to be quickly and easily repaired in the field. If in performing the DC resistance check described previously. A significant change in resistance is noted, or if for any reason the resistive element should fail, inexpensive replacement resistors are available.
Maintenance Figure 2 Removing the Resistor 1/4-20 x 2-1/2 6 Socket Head Cap Screw (6 Req'd) 5 Water Chamber With O-Ring Inner Seal 3 4 10 O-Ring, Outer O-Ring Inner Resistor 2 17 Resistor Sleeve Ground Cap, Resistor (Normally Remains Inside Water Chamber 3 ) 9 Inner Flow Tube 8 O-Ring 7 1 Outer Flow Tube 12 Hose Nipple (2) (Not used in Moduload Application) Load Housing
Termaline Load Resistor 8745/8746 Figure 3 RF Input Assembly Inspecting the Unit Note: Perform this once the resistor has been successfully removed. 1. Inspect the resistor carefully to ensure that it is not fractured. Note: In the majority of cases, even in the event of resistor failure, the resistor substrate will remain intact. 2. Examine the inside of the load housing assembly for any apparent damage to the internal parts. 3.
Maintenance Replacing the Resistor 1. Inspect the load housing assembly. See “Inspecting the Unit” on page 13. 2. Insert new resistor [1] into the load housing until it reaches its fitting. 3. Push in the resistor until it bottoms snugly. Note: If resistor seems to be loose, see “Replacing Fractured Resistors” on page 14 for instructions on how to lighten the resistor fitting. 4. Place the inner flow tube [9] inside the resistor. 5. Lower the inner flow tube until it reaches the resistor fitting. 6.
Termaline Load Resistor 8745/8746 2. Loosen and remove the six (6\ 1/4-20 x 1 inch socket head cap screws [16] from the flanged end of the load housing. Note: Use a 3/16 inch Allen wrench. Note: As shown in Figure 2, the outer conductor assembly may now be easily removed. 3. Remove the input center conductor assembly [11] or [13] by pulling it out of the load housing (Figure 3 on page 13). 4. Carefully remove any remaining pieces of the resistor.
Maintenance Removing the Front Connector Assembly Note: This portion of the load unit consists of the inner conductor [11] or [13] and the outer conductor [12] or [14], respectively. 1. Remove the six screws [16] at the front of the housing flange. 2. Remove the front connector assembly and inner conductor. 3. Replace the O-ring seal, if needed. Note: Do not attempt further disassembly of this part. Return to the factory for repair, if necessary; consult the company.
Termaline Load Resistor 8745/8746 7. Prongs of the clamp match side slots in the socket holder. 8. Fit the clamp in the slots. 9. Turn the head screw up snugly. 10. Reverse steps 1 and 2. 11. Perform preoperational checkout. See “Pre-Operational Checkout” on page 6. Replacing the Pilot Light 1. Locate the pilot lamp (P/N 5-970 (-1 or -2)) on the top of the control box. 2. Push down, gently, and twist the pilot lamp lens (P/N 8750-106). 3. Remove the pilot lamp lens. 4. Remove the pilot lamp. 5.
Maintenance Customer Service Any maintenance or service procedure beyond the scope of those in this chapter should be referred to a qualified service center. If you need to return the unit for any reason, request an RMA through the Bird Technologies website (link shown below). All instruments returned must be shipped prepaid and to the attention of the RMA number. Bird Service Center 30303 Aurora Road Cleveland (Solon), Ohio 44139-2794 Fax: (440) 248-5426 E-mail: bsc@bird-technologies.
Termaline Load Resistor 8745/8746 Specifications Power Rating 20,000 Watts lmpedance 50 ohms Input Connectors Model 8745 Model 8746 3-1/8. EIA flanged (50 ohm) 3-1/8. unflanged (50 ohm) flush center conductor Frequency Range 1000 Hz to 900 MHz VSWR 1 kHz to 900 MHz Modes CW, AM, FM, SSB, TV, and certain Pulse types Input Water Temperature Range 5°C to 60°C (41°F to 140°F) AC Power Required 115 V 50/60 Hz or 23O V 50/60 Hz (with optional items only) Water Flow - Minimum Rate 6 GPM (22.
Maintenance Replacement Parts Customer Replacement Part RPK8755-027-2 Consists of 8755-027-2 923-RPK000 8755-025 8755-024 8740-020 8755-005 8755-016 8755-026 923-8740-025 5-099 5-567 5-1127 5-1128 8110-059 8410-009 8740-025 8740-020 Description Resistor 50.
Termaline Load Resistor 8745/8746 Optional Equipment Control and Water Flow Parts - not shown on Figures Qty Description Part Number 1 Water flow switch 5-898-2 1 Control assembly - 115 V Control assembly - 230 V 8750-101-1 8750-101-2 1 Relay retaining clamp 8630-193 1 Time delay relay - 115 V Time delay relay - 230 V 5-1664 5-1665 1 Indicator light 8750-106 * 1 Incandescent lamp - 115 V Incandescent lamp - 230V* 5-970-1 5-970-2 1 Pipe nipple (flow switch) 5-489-1 Hex bushing (flow
Limited Warranty All products manufactured by Seller are warranted to be free from defects in material and workmanship for a period of one year, unless otherwise specified, from date of shipment and to conform to applicable specifications, drawings, blueprints and/or samples.
