BIRD 4314B Operating Instructions Manual

Instruction Book Part Number 920-4314B Rev. C Thruline ® is a Registered Trademark of Bird Electronic Corporation Electronic Corporation Cleveland (Solon) Ohio USA

to any specific part or procedure and do not necessarily appear elsewhere in this publication. Keep Away From Live Circuits Operating personnel must at all times observe normal safety precautions. Do not replace components inside equipment with the high voltage supply turned on. To avoid casualties, always remove power. Do Not Service Or Adjust Alone Under no circumstances should any person reach into an enclosure for the purpose of service or adjustment of equipment except in the presence of some- one who is capable of rendering aid. Safety Earth Ground An uninterruptible earth safety ground must be supplied from the main power source to test instruments. Grounding one conductor of a two conduc- tor power cable is not sufficient protection. Serious injury or death can occur if this grounding is not properly supplied. Shock Hazard Do not attempt to remove a RF transmission line while power is present. Ra- diated RF power is a potential health hazard. Resuscitation Personnel working with or near high voltages should be familiar with modern methods of resuscitation. i

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. This symbol appears on the equipment indicating there is important information in the instruction manual regard- ing that particular area. � Note: Calls attention to supplemental information. 4314B Warning Statements The following warnings appear in the text where there is danger to operating and maintenance personnel, and are repeated here for emphasis. WARNING Exposure to RF power radiation and the possibility of RF shock or burns exists with some operating conditions. Always be sure to turn off the transmitter when connecting or disconnecting a wattmeter. Be sure the transmission line is terminated into a load or antenna. When a Plug-In Element is removed from the RF line socket, the line section center conductor is exposed. Do not put fingers or other objects into the Plug-In Element socket while RF power is applied. WARNING Always be sure transmitter power is off before disconnecting the unit from the transmission line. ii

The following cautions appear in the text whenever a procedure, if not prop- erly followed, could put the equipment in danger of damage and are repeated here for emphasis. CAUTION Do not drop the Thruline Wattmeter or its elements or subject them to hard blows. The microammeter is shock mounted in the wattmeter housing, but its delicate mechanism may be damaged by severe impact. CAUTION Severe damage to the Plug-In Element or wattmeter can result from exposure to excessive RF power. Make sure the Plug-In Element installed in the wattmeter has a sufficiently high wattage rating to handle the line load when it is first applied to the RF line. CAUTION Use reasonable care in handling. Do not drop or subject the wattmeter or elements to hard blows as accuracy may be impaired or other damage may result. CAUTION Do not apply RF power to the wattmeter in excess of the full scale range of the element. CAUTION When making low reflection readings using a more sensitive element, take care to insert the element so that it senses reflected power only. Do not rotate the element in the socket so that it is subjected to forward power. This can result in damage to the Plug-In Element, the microammeter, or both. CAUTION If other than Female N type connectors are used, limit power and frequency to the capabilities of the RF coaxial cable or connectors used. Damage to connectors or errors in reading could result. Model 4314B Safety Statements USAGE ANY USE OF THIS INSTRUMENT IN A MANNER NOT SPECIFIED BY THE MANUFACTURER MAY IMPAIR THE INSTRUMENT’S SAFETY PROTECTION. iii

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. UTILISATION TOUTE UTILISATION DE CET INSTRUMENT QUI N’EST PAS EXPLICITEMENT PRÉVUE PAR LE FABRI- CANT PEUT ENDOMMAGER LE DISPOSITIF DE PRO- TECTION DE L’INSTRUMENT. IMPRIEGO QUALORA QUESTO STRUMENTO VENISSE UTILIZZATO IN MODO DIVERSO DA COME SPECIFICATO DAL PRODUTTORE LA PROZIONE DI SICUREZZA POTREBBE VENIRNE COMPROMESSA. SERVICE SERVICING INSTRUCTIONS ARE FOR USE BY SER- VICE -TRAINED PERSONNEL ONLY. TO AVOID DAN- GEROUS 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 NINGÉN SERVICIO A MENOS QUE ESTÉ CAPACITADO PARA HACERIO. WARTUNG ANWEISUNGEN FÜR DIE WARTUNG DES GERÄTES GELTEN NUR FÜR GESCHULTES FACHPERSONAL. iv

SCHOCKS, SID WARTUNGSARBEITEN AUSSCHLIEßLICH VON QUALIFIZIERTEM SERVICEPERSONAL DURCHZUFÜHREN. ENTRENTIEN L’EMPLOI DES INSTRUCTIONS D’ENTRETIEN DOIT ÊTRE RÉSERVÉ AU PERSONNEL FORMÉ AUX OPÉRATIONS D’ENTRETIEN. POUR PRÉVENIR UN CHOC ÉLECTRIQUE DANGEREUX, NE PAS EFFECTUER D’ENTRETIEN SI L’ON N’A PAS ÉTÉ QUALIFIÉ POUR CE FAIRE. ASSISTENZA TECNICA LE ISTRUZIONI RELATIVE ALL’ASSISTENZA SONO PREVISTE ESCLUSIVAMENTE PER IL PERSONALE OPPORTUNAMENTE ADDESTRATO. PER EVITARE PERICOLOSE SCOSSE ELETTRICHE NON EFFETTUARRE ALCUNA RIPARAZIONE A MENO CHE QUALIFICATI A FARLA. RF VOLTAGE MAY BE PRESENT IN RF ELEMENT SOCKET - KEEP ELEMENT IN SOCKET DURING OP- ERATION. DE LA TENSION H.F. PEAT ÊTRE PRÉSENTE DANS LA PRISE DE L’ÉLÉMENT H.F. -CONSERVER L’ÉLÉMENT DANS LA PRISE LORS DE L’EMPLOI. HF-SPANNUNG KANN IN DER HF-ELEMENT-BUCHSE ANSTEHEN -ELEMENT WÄHREND DES BETRIEBS EINGESTÖPSELT LASSEN. PUEDE HABER VOLTAJE RF EN EL ENCHUFE DEL ELEMENTO RF -MANTENGA EL ELEMENTO EN EL ENCHUFE DURANTE LA OPERACION. IL PORTAELEMENTO RF PUÒ PRESENTARE VOLTAGGIO RF - TENERE L’ELEMENTO NELLA PRESA DURANTE IL FUNZIONAMENTO. v

This instruction book guides the user through the operation and maintenance of the Bird Model 4314B RF Directional Thruline Wattmeter. This instruction book is arranged so that the essential information about safety is in the front of the book. Reading the Safety Precautions section be- fore operating the equipment is strongly advised. The remainder of this manual is divided into chapters and sections. At the beginning of each chapter, a general overview describes the contents of that chapter. Operation First time users should read Chapter 1 - Introduction, Chapter 2 - Installation, and Chapter 3 - Theory of Operation, to get an overview of equipment capabilities. An experienced operator can refer to Chapter 4 - Op- erating Instructions. All instructions necessary to operate the equipment are in this chapter. Maintenance All personnel should be familiar with preventive maintenance found in Chap- ter 5 - Maintenance. If a failure should occur, the troubleshooting section will aid in isolating and repairing the failure. Parts For the location of major assemblies or parts, refer to the parts list in Chap- ter 5 - Maintenance. Changes To This Manual We have made every effort to ensure this manual is accurate. If you should discover any errors, or if you have suggestions for improving this manual, please send your comments to our factory. This manual may be periodically updated. When inquiring about updates to this manual refer to the part num- ber and revision level on the title page. vi

Safety Precautions . . . . . . . . . . . . . . . . . . . . . . i Warning Statements . . . . . . . . . . . . . . . . . . . . ii Caution Statements . . . . . . . . . . . . . . . . . . . . iii About This Manual . . . . . . . . . . . . . . . . . . . . . vi Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 1 Purpose and Function . . . . . . . . . . . . . . . . . . . 1 Description . . . . . . . . . . . . . . . . . . . . . . . . 1 Performance Characteristics and Capabilities . . . . . . . . . 1 Power Requirements . . . . . . . . . . . . . . . . . . . . 2 Additional Equipment . . . . . . . . . . . . . . . . . . . 2 Standard Plug-In Elements . . . . . . . . . . . . . . . . . 2 Specifications . . . . . . . . . . . . . . . . . . . . . . . 3 Installation . . . . . . . . . . . . . . . . . . . . . . . . . 5 Portability . . . . . . . . . . . . . . . . . . . . . . . . 5 Connections. . . . . . . . . . . . . . . . . . . . . . . . 5 Theory of Operation . . . . . . . . . . . . . . . . . . . . . 9 Traveling Wave Viewpoint . . . . . . . . . . . . . . . . . 9 Coupling Circuit. . . . . . . . . . . . . . . . . . . . . . 9 Peak Power Operation. . . . . . . . . . . . . . . . . . . 10 Component Description . . . . . . . . . . . . . . . . . . 14 Operating Instructions . . . . . . . . . . . . . . . . . . . 17 Zero Adjust Meter . . . . . . . . . . . . . . . . . . . . 17 Plug-In Element Selection and Insertion . . . . . . . . . . . 17 CW Power Measurements . . . . . . . . . . . . . . . . . 18 Peak Power Measurements. . . . . . . . . . . . . . . . . 18 Load power . . . . . . . . . . . . . . . . . . . . . . . 18 Determining VSWR . . . . . . . . . . . . . . . . . . . . 19 Making Low Reflection Readings . . . . . . . . . . . . . . 22 Testing Lines, Connectors, Filters and Related Components. . . 22 Attenuation By Open Or Short Circuit. . . . . . . . . . . . 23 Measuring Percentage Of Positive Modulation . . . . . . . . 23 Performance Notes . . . . . . . . . . . . . . . . . . . . 25 Shutdown . . . . . . . . . . . . . . . . . . . . . . . . 26 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . 29 Cleaning . . . . . . . . . . . . . . . . . . . . . . . . 29 Preventative Maintenance . . . . . . . . . . . . . . . . . 29 Line Section Care . . . . . . . . . . . . . . . . . . . . 29 Inspection . . . . . . . . . . . . . . . . . . . . . . . . 30

Trouble Shooting . . . . . . . . . . . . . . . . . . . . . 30 Troubleshooting Guide. . . . . . . . . . . . . . . . . . . 31 Battery Test . . . . . . . . . . . . . . . . . . . . . . . 33 Battery Replacement . . . . . . . . . . . . . . . . . . . 33 Meter Replacement . . . . . . . . . . . . . . . . . . . . 34 Instrumentation Module Replacement . . . . . . . . . . . . 36 RF Connector Replacement. . . . . . . . . . . . . . . . . 38 Calibration . . . . . . . . . . . . . . . . . . . . . . . 38 Customer Service . . . . . . . . . . . . . . . . . . . . . 40 Replacement Parts . . . . . . . . . . . . . . . . . . . . 41 Available QC Type Connectors . . . . . . . . . . . . . . . 41

tion-type RF wattmeter designed to measure power flow and load match in 50 ohm coaxial transmission lines. It is intended for use on CW, AM, FM, SSB, TV, and pulse signals only. Description The Model 4314B Thruline Wattmeter is a portable unit contained in a die cast aluminum housing. The unit is equipped with a plastic strap for carrying, four rubber shock feet on the base, and four rubber bumpers on the back which allow the unit to stand vertical or lie flat in a horizontal position when used. For additional protection, the microammeter is specially shock mounted. A slotted screw is provided on the lower front face of the meter for zeroing the pointer. The RF line section face below the meter protrudes slightly from the wattmeter housing with the Plug-In Element socket in the center. The circuit module is mounted on the line section inside the housing. It has an attached phosphor bronze spring contact finger, which protrudes through a lateral hole and into the Plug-In Element socket on the RF line section. The finger has a button on its end which makes connection with the contacts of the Plug-in Element. The silver-plated brass RF line section is precision made to provide the best pos- sible impedance match to the coaxial RF transmission line in which the wattmeter is inserted. At each end of the line section are Bird Quick-Change type RF connec- tors, which may be quickly interchanged with any other Bird “QC” connectors. Performance Character- istics and Capabilities To make measurements, insert a Plug-In Element into the line section socket and rotate it to either stop. Point the element arow in the source to load direction of power flow and the meter will display a reading of forward power. Rotate the element so that the arrow is pointed in the opposite direction to obtain a reflected power reading. With known values of forward and reflected power the load match can now be determined by calculating the VSWR or by using the graphs supplied in this manual (pages 20-21). 1

the wattmeter the capability of indicating peak pulse or envelope power. Power Require- ments The Model 4314B can operate from two different power sources. The wattmeter comes supplied with two 9 V al- kaline batteries which typically provide 20 hours of oper- ation. AC adapters are also available for use with either a 115 or 230 Vac line. Additional Equipment The only additional equipment required by the Model 4314B is a Plug-In Element (see table below). Most of them are designed to read both average and peak power. Some are designed exclusively for peak reading applica- tion. Standard Plug-In Elements Bird Model 4314B RF Directional Thruline Wattmeter 2 Use Frequency (MHz) Power Ranges (Watts) Average of Peak 0.45-2.5 2-30 25-60, 50-125, 100-250, 200-500, 400-1000 60-80, 80-95 95-125, 110-160, 150-250, 200-300, 275-450, 425-850, 800-950 60-80, 80-95, 95-150, 150-250, 200-300, 250-450, 400-850, 800-950 950-1260, 1100-1800, 1700-200, 2200-2300 1000, 2.5 kW, 10 kW 50, 100, 250, 500, 1000, 2500, 5000 5, 10, 25, 50, 100, 250, 500, 1000 1 Watt 2.5 Watts 1, 2.5, 5, 10, 25 Peak Only 25-60, 50-125, 100-250, 200-500, 400-1000 950-1260 2.5 kW, 5 kW, 10 kW 50, 100, 250, 500, 2.5 kW, 5 kW

Insertion VSWR With “N” Connectors 1.05 Max. to 1000 MHz, 1.1 Max. to 2300 MHz Connectors Bird Quick Change “QC” Female N normally supplied RF Power Ranges Average (CW) Mode 100 mW to 10 kilowatts (� 5% of full scale) Peak-pulse or envelope-power mode 100 mW to 10 kilowatts (� 8% of full scale) Frequency Range 0.45 to 2300 MHz (either mode) Pulse Parameters Minimum duty factor 1.0 x 10-4 Minimum repetition rate 30 pps Minimum pulse width 0.4 microseconds at 100-2300 MHz 1.5 microseconds at 26-99 MHz 15 microseconds at 2-25 MHz Weight 3 lb. (1.4 kg) Dimensions 3-5/8”L x 4”W x 7”H (92.1 x 102 x 178 mm) AC Power requirements (using adapter)1 115 Vac. � 10%, 60 Hz 220 Vac, � 10%, 50Hz Batteries Two 9 V alkaline Battery Life 20 hours of operation, typically 1 Use only adapter supplied by Bird Electronic Corporation Introduction 3

not designed for fixed mounting. A strap is provided for carrying purposes. CAUTION Do not drop the Thruline Wattmeter or its elements or subject them to hard blows. The microammeter is shock mounted in the wattmeter housing, but its delicate mechanism may be damaged by severe impact. When transporting the Thruline Wattmeter, it is best to insert the original dust plug, or a Plug-In Element with the arrow pointed down, in the measuring socket, and se- cure it with the catch. This will shunt the meter circuit and serve to protect it by dampening the pointer action during handling or shipping. Also, set the wattmeter con- trols to ON and CW modes. In this position, any unneces- sary battery drain will be avoided. Handle the Plug-In Elements with care at all times as their calibration could be disturbed if they are dropped. WARNING Exposure to RF power radiation and the possibility of RF shock or burns exists with some operating conditions. Always be sure to turn off the transmitter when connecting or disconnecting a wattmeter. Be sure the transmission line is terminated into a load or antenna. When a Plug-In Element is removed from the RF line socket, the line section center conductor is exposed. Do not put fingers or other objects into the Plug-In Element socket while RF power is applied. Connec- tions The Model 4314B Wattmeter is normally supplied with two Female N type connectors which are of the Bird Quick-Change “QC” design. Other “QC” connectors are available as listed in the Replacement Parts list at the back of this manual. Quick-Change connectors can be replaced by removing the four 8-32 screws from each corner of the square flange of 5

6 1-5/16" (33.3mm) 3-3/8" 3-5/8” (92.1mm) (85.7mm) 6-7/8" (174.6mm) 4" (101.6mm) 1-3/4" (44.5mm) Female "N" Q.C. Connectors (2) (Normally Supplied) ON BATTERY CW PEAK 15 80 F.S. = 30 UA. PN 2080 - 002 W ELECTRONIC 20 0 BIRD 10 5 30 40 TT A THRULINE 60 S CORP. R 20 10 40 50 100 20 Figure 1 Model 4314B Outline Drawing

stall the new connector by reversing this procedure. Insert the Model 4314B Thruline Wattmeter in coaxial transmission lines of 50 ohms nominal impedance. The signal source and load connections can be made to either side of the wattmeter with no difference in effect. Use a coaxial transmission line fitted with suitable matching RF connectors. If cables of other than 50 ohms impedance are used, a mismatch will occur which could cause serious in- accuracies in the readings. CAUTION Severe damage to the Plug-In Element or wattmeter can result from exposure to excessive RF power. Make sure the Plug-In Element installed in the wattmeter has a sufficiently high wattage rating to handle the line load when it is first applied to the RF line. Installation 7

Traveling Wave Viewpoint The operation of this wattmeter is based on the travelling wave concept of RF transmission. As RF power is applied to a transmission line, there is a forward wave travelling from the transmitter to the load, and a reflected wave travelling from the load to the transmitter. The closer the load is matched to the transmission line, the smaller the reflected wave will be. To determine the amount of power dissipated in a load resistor, it is necessary to determine the wattage of the forward wave and the wattage of the reflected wave. The difference between the two indicates load power. VSWR (Voltage Standing Wave Ratio) has become a widely used tool in the travelling wave concept. The standing waves which are produced by transmission line mismatch cannot be read directly. However, the VSWR can be easily determined by the use of the VSWR Con- version Nemographs (figures 5-6, pages 20-21), without requiring the use of unwieldy and expensive slotted line equipment. Many users find that the ratio of watts reflected watts forward is more useful than VSWR. Coupling Circuit When the wattmeter is connected into the system, the RF power is directed through the unit’s line section. The air line is a short, uniform section which does not impair the impedance of the RF coaxial line into which it is inserted. When the Plug-In Element is installed in the socket of the line section, the RF waves travelling through the line produce energy in the coupling circuit of the Plug-In Ele- ment by both inductance and capacitance (figure 2). The inductive currents will flow according to the direction of the travelling waves producing them. Therefore, assuming that the Plug-In Element remains stationary, the coupling currents produced from the waves of one direction add in phase, while those produced from the waves of the oppo- site direction subtract in phase. The additive or “arrow” direction is assigned to the forward wave. The element is designed so that the wave components travelling in the opposite direction of the arrow will nearly cancel each other out, making the element highly insensitive to the reverse wave direction. Because of the highly directional characteristics of the element, the resultant direct current 9

only the RF waves travelling in the arrow direction. The Plug-In Element is designed so that it can be rotated 180 degrees in its socket in the line section. When it is rotated, the meter indicates the power in a direction op- posite that of the initial reading. If the forward direction power is read first, the reflected direction power will be read after the Plug-In Element is rotated. The energy re- sulting from the inductively coupled component of the for- ward wave will bring about cancellation as described above. Peak Power Operation The Model 4314B is designed to measure peak power in addition to average power. When the toggle switch is placed in peak mode, battery power energizes the ampli- fier system. If the ac adapter is being used, it energizes relay (K1) and disengages the batteries (figure 3). The battery test circuit is energized when the pushbutton of switch S2 is depressed. If the voltages of the two 9 V batteries are within the limits necessary to properly oper- ate the amplifier circuit, the pointer of the meter deflects beyond the battery test mark on the meter scale. If the pointer fails to reach the mark, the batteries need re- placed. Replacement of both batteries simultaneously will assure that sufficient battery power will be available for extended periods of time (see Chapter 5, Maintenance). The amplifier circuit is designed to provide current to the meter which indicates at a steady state the peak of the power applied to resistor R5. Resistor R5 exactly matches the resistance of meter M so that the existing circuit in the Plug-In Element is loaded exactly the same as during the average reading mode (figure 2). When switch S1 is pressed, the dc input which is nor- mally applied to the meter is interrupted and is applied instead to resistor R5 and differential amplifier Q1. This results in a current gain ratio of approximately 100:1. This output is applied to a resistance bridge consisting of resistors R6, R7, R8, R9, and R10. Variable resistor R8 of this bridge permits zero calibration of the amplifier cir- cuit. Bridge output is applied to differential amplifier U1 which provides a voltage gain of about 1000:1. This ratio represents the surge of voltage from the amplifier which charges capacitor C3 and indicates the minimum pulse duration. Capacitor C3 applies a potential to differential amplifiers Q2 and Q3 as long as the capacitor remains Bird Model 4314B RF Directional Thruline Wattmeter 10

ratio, but unity or slightly less voltage gain. This is ap- plied to meter M to indicate the peak power in the line. A portion of the dc output of amplifiers Q2 and Q3 is fed back to resistor R4 and to amplifier Q1. Resistor R4 is matched to resistor R5 to provide unity gain to the am- plifier. This feedback circuit maintains the output from Q1 and U1 to keep capacitor C3 charged to that value which yields unity closed loop gain. The capacitor continues to energize Q2 and Q3, to main- tain the reading of the meter even though the peak of the pulse is no longer applied to the amplifier assembly input. Only the peak power is indicated even though there is a wide fluctuation of input power. Because of capacitor leakage, diode back resistance, and transistor input current, there will be a decay in the cir- cuit that limits the time the amplifier system will retain its output level. As the circuit decays, the meter will re- turn to zero if no additional pulses are received at resis- tor R5. 11 Theory of Operation

12 RF Coaxial Line XMTR or LOAD LOAD or XMTR Directional Coupling Diode Detector Element Meter DC Contact Circuit Board Figure 2 Schematic Diagram - Element

flow sensed by a Plug-In Element. Contains three scales which correspond to the full scale ratings of various Plug-In Elements. 2 ON/BATTERY Switch When the switch is in the ON mode, CW or peak power will be indicated on the meter. With switch in BATTERY mode, the current state of the battery will be indicated on the me- ter. 3 CW/PEAK Switch When switch is in the CW mode, average power will be indicated on the meter. With switch in the PEAK mode, peak pulse or peak envelope power is indicated on meter. 4 Peak LED Indicates wattmeter is in PEAK mode and power is supplied to the peak sensing circuitry. 5 Plug-In Element Determines whether forward or reflected power is being sensed. When arrow points to load, the instrument senses forward power. When arrow points to transmitter, the instrument senses re- flected power. 6 Meter Zero Adjust Provides a zero adjustment for the meter. 7 DC Jack Input connector for supplying power to peak sensing circuit when the wattmeter is used in conjunction with ac adapter. Bird Model 4314B RF Directional Thruline Wattmeter 14

Thruline WATTMETER MODEL 4314B SERIAL XXXX BIRD ELECTRONIC CORPORATION CLEVELAND (SOLON), OHIO DANGER RF VOLTAGE KEEP ELEMENT IN LINE SOCKET DURING OPERATION 15 80 F.S. = 30 UA. PN 2080 - 002 W ELECTRONIC 20 0 BIRD 10 5 30 40 TT A THRULINE 60 S CORP. R 20 10 40 50 100 20 ON BATTERY CW PEAK 1 2 3 4 5 6 7 18V DC 20 mA Figure 4 Component Diagram

essary to zero the meter under no-power conditions. Rotate Plug-In Element so that the arrow points down. Set wattmeter’s controls to ON and CW modes. Using a small screwdriver, turn the meter’s zero adjust screw clockwise or counterclockwise so that the meter pointer aligns with the zero mark on the meter scale. WARNING Exposure to RF power radiation and the possibility of RF shock or burns exists with some operating conditions. Always be sure to turn off the transmitter when connecting or disconnecting a wattmeter. Be sure the transmission line is terminated into a load or antenna. When a Plug-In Element is removed from the RF line socket, the line section center conductor is exposed. Do not put fingers or other objects into the Plug-In Element socket while RF power is applied. CAUTION Use reasonable care in handling. Do not drop or subject the wattmeter or elements to hard blows as accuracy may be impaired or other damage may result. CAUTION Do not apply RF power to the wattmeter in excess of the full scale range of the element. Plug-In Element Selection and Insertion The elements determine the power range to be read on the meter scale. The major markings (50 W, 100 W, etc.) are the full scale power value for that element. Elements are also marked for frequency range. The transmitter fre- quency must be within the band of the element used. RF power measurements are made with the insertion of a Plug-In Element. Insert the element into the line section’s receptacle. Forward power is indicated when the arrow on the element points in the direction of power flow; from 17

made with the element rotated 180� and the arrow point- ing towards the transmitter. The element must be rotated fully when power measurements are being made. The in- dex pin protruding from the element’s body should rest against the stop on the line section in both the forward and reflected position. The small catch in the lower left hand corner of the casting face should press down on the shoulder of the Plug-In Element. This will keep the Plug-In Element in proper alignment and insure good contact with the dc pickup, the lower edge of the element and the line section body. CW Power Measure- ments Set the wattmeter controls to the ON and CW modes, and read the appropriate meter scale corresponding to the element full-scale value. Peak Power Measure- ments Set the ON/BATTERY switch to the BATTERY mode. If the pointer of the meter indicates below the battery test zone, the batteries must be replaced. (see chapter 5, Maintenance) Return ON/BATTERY switch to the ON position. Set CW/PEAK switch to PEAK mode, and read the appropriate meter scale corresponding to the element full-scale value. Load power Where an appreciable amount of power is reflected, as with an antenna, it is necessary to subtract the reflected from the forward power to obtain the effective load power. Power delivered to and radiated by an antenna is given by: Wl = Wf - Wr Where: Wl = load power Wf = forward power Wr = reflected power A load closely matched to 50 ohms resulting in a VSWR of 1.2 or less, will require less than a one percent correc- tion. A good RF load resistor, such as a Bird Termaline Load Resistor, will produce this sort of negligible or un- readable reflected power. The Model 4314B Thruline Wattmeter used with a Bird Termaline Load Resistor of proper power rating forms a highly useful absorption wattmeter. Since the reflected power will be negligible, it will be unnecessary to rotate the element from the forward direction. Bird Model 4314B RF Directional Thruline Wattmeter 18

provide direct VSWR readings. In most cases, operators find that the ratio of forward to reflected power is of equal use. However, VSWR readings can be determined very easily by the use of the provided graphs as follows: Determine the forward and reflected power as described above. Using the appropriate VSWR Conversion Nomograph (pages 20-21), determine the intersection of the forward and reflected power values. The slanted line passing clos- est to this point indicates the VSWR. 19 Operating Instructions

20 10 15 20 0.5 1.0 1.5 2.0 2.5 3.0 4.0 5.0 25 30 40 50 100 150 200 300 400 500 .2 .4 .6 .8 1.0 1.2 1.4 1.6 1.8 2.0 4 6 8 10 12 14 16 18 20 VSWR= 1+ Reflected Power Forward Power Reflected Power Forward Power 1 FORWARD POWER - WATTS REFLECTED POWER - WATTS 3.0 2.5 2.0 1.6 1.5 1.4 1.3 1.25 1.20 1.16 1.14 1.12 1.10 1.09 1.08 1.07 1.06 1.05 1.8 10 4.0 VSWR Figure 5 VSWR Conversion Nomograph

REFLECTED POWER - WATTS 10 4.0 VSWR Figure 6 VSWR Conversion Nemograph

flection readings. This can be done using a more sensitive element, provided that care is taken to prevent applica- tion of high forward power to the low-power element. This procedure is limited to use with higher power trans- mitters only. Measure watts forward, using the proper Plug-In Ele- ment. Reverse the arrow direction of the element to de- termine the general level of reflected power. Remove the Plug-In Element and insert a lower power el- ement which has a maximum rating of more than the re- flected power indicated in the first measurement. Carefully insert the element so that it reads reflected power only. CAUTION When making low reflection readings using a more sensitive element, take care to insert the element so that it senses reflected power only. Do not rotate the element in the socket so that it is subjected to forward power. This can result in damage to the Plug-In Element, the microammeter, or both. Read the reflected power on the meter in the usual man- ner. When using the two-element method of reading low re- flected power, we do not recommend using a pair of ele- ments which has a full scale power differential of greater than 10 to 1. Testing Lines, Connectors, Filters and Related Components Lines, connectors, filters, and related components can be tested using the Thruline Wattmeter. The method of test- ing depends upon the circumstances involved for any par- ticular test. Some of these tests are listed below: The standing wave ratio or the reflected-power to forward-power ratio of a line can be determined by termi- nating the line with a good load resistor, such as a Bird Termaline Load Resistor. Proceed as described under de- termining VSWR. Low reflected power may be measured as described above. Line attenuation (power lost as heat in the line) can be determined by inserting the line of unknown value be- tween two Thruline Wattmeters. The end of the line must Bird Model 4314B RF Directional Thruline Wattmeter 22

line can be determined by comparing readings made at the two ends. Allowances must be made for normal in- strument error where very small values of attenuation are involved. Some correction may be made by direct rigid connection of the Thruline Wattmeters. Attenuation By Open Or Short Circuit Attenuation can also be determined by the open circuit method. The test set exhibits good equality between for- ward and reflected readings when the load connector is open or short circuited. When this is checked on an open circuit and an open-circuited length of line of unknown attenuation is connected to the load connector, the ratio shown is the attenuation in two passes along the line (down and back). To convert the reading to decibels, di- vide it in half or double the line length because twice the line length is being measured (down and back). This mea- surement must be supplemented with a reflected power to forward power ratio check or with a dc continuity check or leakage check, since open circuits or shorts may exist part of the way along the line. Attenuation can also be determined as described above by using a short circuit rather than an open circuit. The open circuit method is preferred because the initial equal- ity (forward power to reflected power) is more easily achieved in an open circuit. Measuring Percentage Of Positive Modulation To measure the percentage of positive modulation in an amplitude modulation system, employ the average and peak reading characteristics of the unit since: Percentage pos. mod. = E E E MAX CARRIER CARRIER � �100 By substitution we get: Percentage pos. mod. = P P P P C C � � � ��� � � �100 Where: PP = peak power as read with CW/PEAK switch in PEAK mode. PC = carrier power as read with CW/PEAK switch in CW mode Or: Percentage pos. mod.= P P P P P C C C � � � ��� � � �100 23 Operating Instructions

24 Figure 7 Graph Converting Carrier Power and Peak Power to Percent

Percentage pos. mod. = P P P C � � � ��� � � 1 � 100 After determining average and peak readings, find the in- tersection of the carrier and peak powers on figure 7 to determine the percentage of positive modulation. Performance Notes Although the Model 4314B Thruline Wattmeter is equipped with Quick-Change connectors, it must be re- membered that the power rating and insertion loss may be affected if other than “N” type connectors are used. Power limits must be governed by the type of connector or transmission line used. For other types of Quick-Change connectors, see Chapter 5 for the replace- ment parts list. When a Model 4314B is used to match a load to a trans- mitter and a good match is obtained, removing the in- strument will not cause any change in the conditions. A well matched 50 ohm load can be placed at the end of a 50 ohm transmission line of any length without altering conditions at the transmitter. When the load is not well matched, like an antenna with a VSWR of 1.5 or 2.0, line length becomes critical since the length of line between a mismatched load and the source transforms the impedance of the load as seen at the source. If the adjustments for maximum power trans- fer were made with the Model 4314B in place, removing it shortens the line by four inches plus two connectors. This still is no cause for concern at low frequencies where four to five inches is a small fraction of a wavelength. At higher frequencies; e.g., above 100 MHz, the power out- put and frequency of the source may be affected. To insure that the impedance is identical on either side of ½ wavelength in your transmission line with the Model 4314B either in or out of the line, it is only necessary to insert or remove a ½ wavelength. Make up a length of cable which, when added to the Thruline Wattmeter, equals ½ wavelength at the fre- quency of measurement. If more than one frequency is in- volved, then a separate cable is needed for each frequency. Use figure 8 to determine the cable length re- quired. Operating Instructions 25

length is measured from tip to tip of center pin of plugs. � When using other connectors, the cable length is measured from the ends of the outer conduc- tor of the connectors. Bird Model 4314B RF Directional Thruline Wattmeter 26

CW/Peak switch to CW mode and the ON/BATTERY switch to the ON position. Leaving the unit in other switch positions will shorten battery life. WARNING Always be sure transmitter power is off before disconnecting the unit from the transmission line. 28

they should be cleaned with a good contact cleaner or dry cleaning solvent on a cotton swab stick. It is important to keep the following surfaces clean: � Socket bore � Element body circumference � Bottom rim of the socket in the line section � DC contacts on the element Take care not to disturb the spring finger of the DC con- tact when cleaning the socket bore. The spring finger can be manually adjusted. The button must be pushed out far enough to make good contact with the element body but it must not restrict the entry of the element. Clean the meter and meter housing using a cloth moist- ened with a mild detergent solution. Do this only when necessary and take care not to allow water to enter any of its circuitry as damage may result. CAUTION Use reasonable care in handling. Do not drop or subject the wattmeter or elements to hard blows as accuracy may be impaired or other damage could result. Preventative Maintenance Care and maintenance required for the 4314B Thruline Wattmeter is primarily limited to cleaning. Keeping the Plug-In Element in the socket of the line section as much as possible serves as an effective seal against the entry of dust and dirt and to prevent damage to the meter. An aluminum dust plug may be used to cover the socket opening when the element is removed. Line Section Care The RF connectors on the line section should also be pro- tected against the entry of dust and dirt by keeping them 29

line. If there is evidence of contamination inside the line sec- tion, the reachable portions should be cleaned and the in- terior carefully blown out. Do not attempt to remove the RF center conductor under any circumstances. Any at- tempt to do so will damage the assembly Inspection Periodic inspections should be performed at six-month in- tervals. Inspect the meter for a cracked meter glass. Inspect wattmeter line section for a damaged or missing latch and pivot pin assembly. Inspect all “QC” connectors for bent, broken, or missing pins. Trouble- shooting Due to its complexity, field repair of the Model 4314B Thruline Wattmeter is recommended only for certain mal- functions. Only those functions within the scope of nor- mal maintenance are listed. The following guide contains troubleshooting information for problems which can occur during normal operation. Locate the problem, review the possible cause and per- form the corrective action listed. If a malfunction is not listed or not corrected by the listed corrective actions, notify a qualified service center for further instructions. Bird Model 4314B RF Directional Thruline Wattmeter 30

(CW or PEAK) No radio frequency Turn on transmitter. Check transmitter op- erational conditions, refer to operating in- struction manual of equipment used. Check connections, in- terconnecting cables, and auxiliary in-line equipment. Arrow on element pointing in wrong di- rection Rotate element so that arrow points in direc- tion of RF power flow. Meter burned out or damaged Replace meter. (page 34) No pick-up from dc contact Clean line section and element. (page 25) Defective Plug-In Ele- ment Check element. Re- place element if defec- tive. No meter indication (PEAK only) Faulty instrumentation module Check module. If faulty, replace instru- mentation. (page 36) Dead or low battery Depress ON/BATTERY selector switch to the BATTERY position. If the battery test indi- cates weak batteries, replace them with new ones. (page 33) If pointer does not move from zero during the battery test, re- move the batteries and measure their voltage. If less than 6.25 volts, replace the batteries. (page 33) 31 Maintenance

rate Low battery Depress ON/BATTERY selector switch to the BATTERY position. If the battery test indi- cates weak batteries, replace them with new ones. (page 33) Shorted or opened cable Check connections, in-line equipment, in- terconnecting cables, and auxiliary in-line equipment. Wattmeter out of calibration Check calibration. (page 36) Intermittent or incon- sistent Faulty transmission line, line connections, antenna, or load condi- tions Inspect and correct meter operation or load. Dirty line section, dc contact, and/or ele- ment Clean line section and element. (page 27) Sticky meter Replace meter. (page 34) High VSWR or high percentage reflected power Bad load or poor load, antenna, or connectors Replace connectors. (page 36) Shorted or open trans- mission line Replace transmission line. Foreign material in line section or in RF connector bodies Check for foreign ma- terial and clean as re- quired. (page 27) 32 Bird Model 4314B RF Directional Thruline Wattmeter

line batteries to supply power for the peak circuitry. To test these batteries, set the ON/BATTERY switch to the BATTERY position. The meter pointer should travel to the right of the “BAT.TEST” mark. If the pointer stops below the mark, replace the batteries. Battery Replacement Remove the back cover by unscrewing the four 8-32 Phil- lips flat head screws located two on each side of the me- ter housing near the back edge at the top and bottom of the sides. Pull the cover straight off. Rotate the battery in its clip, then pull upward freeing the battery. Remove the snap-on battery connector. Insert the battery into the clip and replace. Repeat above procedure for the other battery. 33 Maintenance Inside Back + Figure 9 Battery Replacement

Phillips flat head screws located two on each side of the meter housing near the back edge at the top and bottom of the sides. Pull the cover straight off. Loosen the two 8-32 nuts on the back of the meter that secure the meter leads and remove the leads. Remove the two 10-32 oval head Phillips screws that se- cure the meter shock ring located on each side of the me- ter housing just opposite the meter. Pull the meter and shock ring assembly out of the hous- ing from the back. If the three rubber shock mount but- tons, P/N 4420-098, that the meter rests on are to be reused, be careful not to lose them. However, if the re- placement shock ring, P/N 4410A261, is to be used in- stead, the buttons may be discarded. Remove the meter retaining ring and shock mount from the meter. Replace the meter. If the replacement shock ring is used, peel off the white strip covering the adhesive backing. Carefully adhere the shock ring to the front bezel flange. Be sure to observe the polarity when replacing the leads to the meter, black to negative, red to positive. Zero adjust the meter. 34 Bird Model 4314B RF Directional Thruline Wattmeter

MULTIPY SWITCH SETTING BY ELEMENT FACTOR ! DANGER RF VOLTAGE KEEP ELEMENT IN LINE SOCKET DURING OPERATION OFF O.1 0.3 WATTS THRULINE Thruline WATTMETER MODEL 4314B SERIAL NUMBER XXX BIRD ELECTRONIC CORPORATION CLEVELAND (SOLON), OHIO + Figure 10 Meter Replacement

The in- strumentation module contains the line section and cir- cuit board chassis as an integral part. Using a 7/16 wrench, loosen the dress nut on the CW/PEAK switch. Care should be taken not to scratch the label. Remove the wire assemblies from the batteries, meter, and dc jack. Remove the battery wires (item 4) first at the printed circuit board by pulling up on the slip-on con- nector. Next remove the dc jack wires (item 5). Remove the meter wires (item 3) also at the printed circuit board. Care should be taken not to break the wires. Note the wire location for ease of reassembly. Remove the two oval head Phillips screws located on the front face of the unit on either side of the line section el- ement port. Pull the instrumentation module straight out from the back of the unit. Replace the connector. Zero adjust the meter. 36 Bird Model 4314B RF Directional Thruline Wattmeter

power and frequency to the capabilities of the RF coaxial cable or connectors used. Damage to connectors or errors in reading could result. RF Connector Replace- ment Remove the four 8-32 pan head screws from the corners of the connector flange. Carefully pull the connector straight off. Replace the connector. Calibration Zero adjustment of the meter is the only calibration re- quired for the 4314B. This should be done any time the meter pointer is not exactly aligned with the zero mark on the meter scale when no power is being applied. Zero adjustment must also be performed after the meter or in- strumentation module has been replaced. To assure that the meter reads correctly for both average and peak operation, apply direct current from a battery source to the input of the amplifier circuit (figures 5 and 6, pages 20-21). The steady direct-current peak level should be the same as the average current level because no peaks exist in this current. Apply a direct current and adjust as necessary so that the same reading is at- tained in both average and peak modes. Install a voltage-dropping variable voltage dividing poten- tiometer and a battery in series with the input of the am- plifier. Make sure the resistor is set for zero output. Connect the positive (+) side of the circuit to input and the negative (-) side to ground. Install a voltmeter across the circuit. Slowly operate the potentiometer to adjust output to apply approximately 21 millivolts. Use a suit- able resistive network. Check the reading of the meter. The pointer should devi- ate or travel about half of full scale. Set the CW/PEAK switch to PEAK mode while watching the meter pointer. There should be no deviation of the pointer from average to peak reading. 38 Bird Model 4314B RF Directional Thruline Wattmeter

than for average reading, adjust potentiometer R8 until the two readings coincide. 39 Maintenance Calibration Potentiometer Access Hole X Figure 12 Calibration Potentiometer

and calibration department at our corporate headquar- ters. This department is set up to provide our customers with the best possible service of Bird equipment. All instruments returned for service must be shipped pre- paid and to the attention of the Customer Service Group. Bird Electronic Corporation 30303 Aurora Rd Cleveland (Solon), OH 44139-2794 Phone: (440) 248-1200 Fax: (440) 248-5426 40 Bird Model 4314B RF Directional Thruline Wattmeter

4314-116 5 1 DC jack wire assembly 4314-117 6 1 Meter wire assembly 4314-119 7 2 9 V battery 5-1375 8 2 “QC” connectors (Female N normally supplied)* 9 1 Housing cover assembly 4314-114 10 1 Dress nut 5-1670 11 1 AC to dc converter 115 Vac 230 Vac 5-1864 5-1940 *Available QC Type Connectors N-Female 4240-062 BNC-Male 4240-132 N-Male 4240-063 LT-Female 4240-018 HN-Female 4240-268 LT-Male 4240-012 HN-Male 4240-278 C-Female 4240-100 LC-Female 4240-031 C-Male 4240-110 LC-Male 4240-025 UHF-Female (SO-239) 4240-050 BNC-Female 4240-125 UHF-Male (PL-259) 4240-179 7/8" EIA Air Line 4240-002 Items 10 and 11 not shown in figure 13. 41 Maintenance

Inside Back + 1 2 3 4 5 6 7 8 9 Figure 13 Replacement Parts

material and workmanship for a period of one (1) year, unless otherwise spec- ified, from date of shipment and to conform to applicable specifications, draw- ings, blueprints and/or samples. Seller’s sole obligation under these warranties shall be to issue credit, repair or replace any item or part thereof which is proved to be other than as warranted; no allowance shall be made for any labor charges of Buyer for replacement of parts, adjustment or re- pairs, or any other work, unless such charges are authorized in advance by Seller. If Seller’s products are claimed to be defective in material or workmanship or not to conform to specifications, drawings, blueprints and/or samples, Seller shall, upon prompt notice thereof, either examine the products where they are located or issue shipping instructions for return to Seller (transporta- tion-charges prepaid by Buyer). In the event any of our products are proved to be other than as warranted, transportation costs (cheapest way) to and from Seller’s plant, will be borne by Seller and reimbursement or credit will be made for amounts so expended by Buyer. Every such claim for breach of these warranties shall be deemed to be waived by Buyer unless made in writ- ing within ten (10) days from the date of discovery of the defect. The above warranties shall not extend to any products or parts thereof which have been subjected to any misuse or neglect, damaged by accident, rendered defective by reason of improper installation or by the performance of repairs or alterations outside of our plant, and shall not apply to any goods or parts thereof furnished by Buyer or acquired from others at Buyer’s request and/or to Buyer’s specifications. In addition, Seller’s warranties do not extend to the failure of tubes, transistors, fuses and batteries, or to other equipment and parts manufactured by others except to the extent of the original manufac- turer’s warranty to Seller. The obligations under the foregoing warranties are limited to the precise terms thereof. These warranties provide exclusive remedies, expressly in lieu of all other remedies including claims for special or consequential damages. SELLER NEITHER MAKES NOR ASSUMES ANY OTHER WARRANTY WHATSOEVER, WHETHER EXPRESS, STATUTORY, OR IMPLIED, IN- CLUDING WARRANTIES OF MERCHANTABILITY AND FITNESS, AND NO PERSON IS AUTHORIZED TO ASSUME FOR SELLER ANY OBLIGA- TION OR LIABILITY NOT STRICTLY IN ACCORDANCE WITH THE FOREGOING.

Manufacturer: Bird Electronic Corporation 30303 Aurora Road Cleveland, Ohio 44139-2794 Product: Thruline Wattmeter Models: 4314B 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; EN 55011:1991 - Emissions: (Class B) IEC 801-2:1984, Part 3 - EMF Immunity IEC 801-4:1988, Part 4 - Fast Transient/Burst Immunity These standards are in accordance with EMC Directive (89/336/EEC). European Standard EN 61010-1:1993 - Part 1:General Requirements This standard is in accordance with Low Voltage Directive (73/23/EEC), 1973 The technical documentation file required by this directive is maintained at the corporate headquarters of Bird Electronic Corporation, 30303 Aurora Road, Cleveland, Ohio 44139 � � � � Bob Gardiner Director of Quality Bird Electronic Corporation