INSTRUCTION BOOK OPERATING INSTRUCTIONS TERMALINE COAXIAL LOAD RESISTOR MODEL 8251D208 Electronic Corporation Cleveland (Solon) Ohio USA Copyright 1998 by Bird Electronic Corporation Instruction Book Part Number 920-8251D208 Rev.
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.
CAUTION Caution notes call attention to a procedure which if not correctly performed, could result in damage to the instrument. This symbol appears on the equipment indicating there is important information in the instruction manual regarding that particular area. + Note: Calls attention to supplemental information. Warning Statements The following safety warnings appear in the text where there is danger to operating and maintenance personnel and are repeated here for emphasis.
CAUTION The unit is factory filled to the proper level with 1.1 gallons (4.2 liter) of Bird P/N 5-1070. No other coolant should be used CAUTION Do not leave out the O-Ring seal, P/N 5-504 when interchanging the vent and shipping plugs. 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.
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 DESCARGÉAS ELÉCTRICAS, NO REALICE NINGÚN SERVICIO A MENOS QUE ESTÉ CAPACITADO PARA HACERIO. WARTUNG ANWEISUNGEN FÜR DIE WARTUNG DES GERÄTES GELTEN NUR FÜR GESCHULTES FACHPERSONAL.
About This Manual This instruction book covers the model 8251D208 Termaline Coaxial Resistor. This instruction book is arranged so that essential information on safety is contained 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 divided into Chapters and Sections.
Bird Model 8251D208 vi Termaline Coaxial Load Resistor
Table Of Contents Safety Precautions. . . . . . . . . . . . . . . . . . . . . . . i Warning Statements. . . . . . . . . . . . . . . . . . . . . . . ii Caution Statements.. . . . . . . . . . . . . . . . . . . . . . . ii Safety Statements. . . . . . . . . . . . . . . . . . . . . . . . iii About This Manual. . . . . . . . . . . . . . . . . . . . . . . . v Introduction. . . . . . . . . . . . . . . . . . . . . . . . . 1 Purpose and Function. . . . . . . . . . . . . . . . . . . . 1 Applications. . . . . . . .
Bird Model 8251D208 Termaline Coaxial Load Resistor Operation Under Abnormal Conditions. . . . . . . . . . . . . 9 Shutdown. . . . . . . . . . . . . . . . . . . . . . . . . 9 Emergency Shutdown. . . . . . . . . . . . . . . . . . . . 10 Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . 11 Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . 11 Cleaning. . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Inspection. . . . . . . . . . . . . . . . . . . . . . . . . . .
Sales Facilities. . . . . . . . . . . . . . . . . . . . . . 17 Preparation for Shipment. . . . . . . . . . . . . . . . . . . . . 17 Replacement Parts List.. . . . . . . . . . . . . . . . . . . . .
Bird Model 8251D208 x Termaline Coaxial Load Resistor
Chapter 1 Introduction This publication covers the Termaline Coaxial Load Resistor Model 8251D208. The Termaline Coaxial Load Resistor will generally be referred to as a load thoughout this manual. This chapter contains introductory information including product specifications; items supplied; and accessory items available. Purpose and Function The Bird Termaline Coaxial Load Resistor is a portable, general purpose 50 ohm coaxial transmission line termination.
Bird Model 8251D208 Environmental Requirements Items Supplied Termaline Coaxial Load Resistor The load should be operated in a dust and vibration free, dry environment. Allow at least 6 inches (153 mm) of clearance around the unit to permit adequate heat dissipation. s Load Resistor s Instruction Book Items Required Matching connector on the coaxial transmission line to which the load will be attached.
Introduction Specifications Impedance, Nominal VSWR: Connector: Power Range: Frequency Range: Ambient Temperature: Cooling Method Dimensions: Weight: Net Shipping Operating Position: Finish: European Safety: 50 ohms 1.065:1 1-5/8" EIA flanged 1000 watts continuous 470 to 860 MHz -40°C to +45°C (-40°F to +133°F) Oil dielectric and convection currents 17-29/32"L x 5-15/16"W x 8-1/2"H (455 x 151 x 216 mm) 25 lb. 8 oz. (11.6 kg) 30 lb. (13.
Bird Model 8251D208 4 Termaline Coaxial Load Resistor
Chapter 2 Theory of Operation This load consists essentially of a carbon film resistor on a ceramic substrate immersed in a dielectric coolant. The resistor, individually selected for its accuracy, is enclosed in a special exponentially tapered housing. This provides a linear reduction in surge impedance directly proportional to the distance along the resistor.
Bird Model 8251D208 Termaline Coaxial Load Resistor Figure 1 Shipping Plug O-ring seal Figure 2 Vent Plug O-Ring Seal 6
Chapter 3 Installation CAUTION This equipment is designed for operation in a horizontal position only, with mounting brackets down. Do not operate in any other manner. The load is to be installed, and operated in a horizontal position. The load is shipped horizontal, and normally stands on its base brackets. The load may be used for portable operation and stand free, or it may be secured to a bench top or other flat surface for a fixed installation.
Bird Model 8251D208 Connecting to the Transmitter Termaline Coaxial Load Resistor Connect the load to the transmitting equipment under test with 50 ohm coaxial cable (RG-8A/U, RG-9/U, RG-213/U or equivalent). After the transmitter has been connected to the load, proceed according to the transmitter manufacturer’s instructions. When reconnecting the antenna, it may be necessary to slightly readjust the transmitter due to possible differences in VSWR between the load and the antenna system.
Chapter 4 Operating Instructions Normal Operation CAUTION Do not operate this equipment over the rated 1000 watts continuously. Damage to the resistive element will result. The load has no indicators or operating controls, therefore it requires no special operating procedures or surveillance when the stated performance limits are not exceeded. Follow the instructions pertaining to the specific transmitting equipment.
Bird Model 8251D208 Termaline Coaxial Load Resistor Emergency Shutdown WARNING Never attempt to connect or disconnect RF equipment from the transmission line while RF power is being applied. Leaking RF energy is a potential health hazard. Turn off RF power at the source.
Chapter 5 Maintenance This chapter contains information for cleaning, inspection, troubleshooting, and performance of this load. Troubleshooting Refer to this table when troubleshooting the load for aid in isolating the problem, and for possible causes and remedies.
Bird Model 8251D208 Termaline Coaxial Load Resistor Inspection With the rugged and simple construction of the loads, periodic inspection will be necessary at only about six month intervals. Inspection should include the items listed below: 1. Oil Leakage - check for coolant oil leaking around the radiator tank, particularly at the front and back around the underside of the clamping band. If leakage is observed, refer to the troubleshooting section and, check tightness of the front and rear clamping bands.
Maintenance 3. Replace vent plug. If coolant needs to be added, refer to the RF Load Resistor section. DC Resistance Measurement Preparation and Tools Required Be sure that the vent plug is installed. Preparation: s Tools: Common hand tools s Ohmmeter with an accuracy of ± 1% at 50 ohms.
Bird Model 8251D208 Termaline Coaxial Load Resistor Figure 4 Measuring DC Resistance 50.0 These tests are by no means a necessity to the operation of the load but merely guidelines for the users information. Disassembly There are no special techniques required for the repair or replacement of components in this Termaline Load Resistor.
Maintenance 5. Inspect the diaphragm seal and replace it if it is not soft and pliable, or shows signs of surface cracks. 6. Replace the coolant if it appears contaminated, i.e., if it is not clear. The expansion tank is vented through the vent plug, P/N 2450-094. The unit unscrews from a socket on top of the tank, but is not itself subject to disassembly. The shipping plug is sealed by compression of an O-Ring, P/N 5-504, which should be included when replacing the vent plug.
Bird Model 8251D208 Termaline Coaxial Load Resistor 1. Gently pry apart the fins next to each stud just enough to clear the handle thickness. 2. With the fins pried apart sufficiently, slide each leg of the handle off its respective stud. Assembly Diaphragm and Coolant Oil To assemble the unit after replacing the diaphragm or adding coolant, follow the instructions below. 1. Install the diaphragm and the rear cover. 2. Install the clamping band and tighten the clamp screw with a screwdriver. 3.
Maintenance Storage No special preparations for storage are necessary other than to cover the equipment to keep out dust and dirt. Store the unit in a dry and dust-free environment where the ambient temperature will remain within the -40°C to +45°C (-40°F to +113°F) working range of the load. Customer Service Any maintenance or service beyond the scope of those provided in this section should be referred to a qualified service center.
Bird Model 8251D208 Termaline Coaxial Load Resistor Replacement Parts List Qty. Description RF Section Assembly 1 Radiator Assembly 1 Diaphragm Cover Guard 1.1 gals Coolant Oil - Dielectric (4.
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.
DECLARATION OF CONFORMITY Manufacturer: Bird Electronic Corporation 30303 Aurora Road Cleveland, Ohio 44139-2794 Product: TERMALINE RF COAXIAL LOAD RESISTOR Model: 8251D208 The undersigned hereby declares, on behalf of Bird Electronic Corporation of Cleveland, Ohio, that the above-referenced product, to which this declaration relates, is in conformity with the provisions of the following standards; 1. European Standard EN 61010-1:1993 - Safety, Group II.
