MULTI-PURPOSE THRULINE® WATTMETER RF POWER ANALYST® MODEL 4391A CABLE AND ANTENNA TESTER FOR WIRELESS SYSTEMS OPERATING INSTRUCTIONS ©Copyright 2012 by Bird Electronic Corporation Instruction Book Part Number 920-4391A 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. WARNING Keep Away From Live Circuits Operating Personnel must at all times observe general safety precautions.
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 caution symbol appears on the equipment indicating there is important information in the instruction manual regarding that particular area Note: Calls attention to supplemental information.
Caution Statements The following equipment cautions appear in the text and are repeated here for emphasis. CAUTION Long-term storage of this instrument can affect battery performance and reduce battery life. Do not store the instrument for long periods of time without recharging the batteries (refer to page 18). Failure to comply may result in reduced battery charge and shortened battery life. On pages 7 and 16.
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.
UNITS ARE EQUIPPED WITH RECHAREABLE BATTERIES. THESE ARE TO BE REPLACED BY AUTHORIZED SERVICE PERSONNEL ONLY!!! LAS UNIDADES VIENEN EQUIPADAS CON BATERIAS RECARGABLES. ¡¡¡Y SOLAMENTE EL PERSONAL DE SERVICIO AUTORIZADO PUEDE REEMPLAZARLAS!!! GERÄTE SIND MIT WIEDER AUFLADBAREN BATTERIEN BESTÜCKT. BATTERIEN SIND NUR VON QUALIFIZIERTEM SERICE PERSONAL AUSZUWECHSELN!!! CES DISPOSITIFS SONT ÉQUIPÉS DE BATTERIES RECHARGEABLES.
BE SURE THE 115/230V AC VOLTAGE SELECTOR IS SET TO THE PROPER LINE VOLTAGE, AND THE CORRECT AC LINE FUSE IS INSTALLED BEFORE AC POWER IS APPLIED. S'ASSURER QUE LE SÉLECTEUR DE TENSION 115/230V C.A. EST BIEN RÉGLÉ POUR LA TENSION DU RÉSEAU ET QUE LE FUSIBLE DE LIGNE C.A. CORRECT EST EN PLACE AVANT DE METTRE SOUS TENSION C.A. CERCIORESE QUE EL SELECTOR DE VOLTAJE DE 115/230V CA ESTE COLOCADO A LA LINEA DE VOLTAJE APROPIADA Y QUE EL FUSIBLE ESTE INSTALADO A LA LINEA CA ANTES DE APLICAR LA CORRIENTE ALTERNA.
RF VOLTAGE MAY BE PRESENT IN RF ELEMENT SOCKET - KEEP ELEMENT IN SOCKET DURING OPERATION. 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.
About This Manual This manual covers the operating and maintenance instructions for the following models: 4391A 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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 Safety Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i Warning Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i Caution Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii Safety Statements . . . . . . . . . . . . . .
Chapter 5 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Preventive Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Cleaning and Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Long-term Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 1 Introduction The Model 4391A is a multi-purpose Radio Frequency wattmeter designed around a microcomputer. A program stored in permanent memory controls the operation of the instrument at all times, permitting the detection and correction of various error sources and the refinement of the raw data produced by the directional detectors.
Description The instrument is housed in an aluminum case approximately 4-3/8 inches high by 9-5/8 inches deep by 6-1/4 inches wide (111 mm x 244 mm x 159 mm) including connections, see Figure 1. At each end of the line section are Bird QuickChange type RF connectors which may be easily interchanged with any other Bird QC connector. See Bird Catalog for types available.
Chapter 2 Theory of Operation Description of Operation Figure 2 is a block diagram of the major functional parts of the Model 4391A RF Wattmeter. The Microcomputer integrated circuit shown, controls all the other portions of the instrument, which fall into two major groups. Figure 2 Circuit Block Diagram Keyboard, Range Switches, and Display Group The keyboard and range switches serve only to pass information to the computer. The display, of course, returns information from the computer to the operator.
Elements, Analog Circuitry, and A/D Converter These components are controlled by the computer. The Plug-in Elements in the line section provide low level positive voltages related to the instantaneous value of power (see Figure 3). The first group of solid state switches selects the forward element, the reflected element, or ground as the input to the preamplifier which boosts these signals to 0.1 to 2.0 volt range.
ary, the coupling currents produced from the waves of one direction will add in phase, and those produced from waves of the opposite direction will accordingly subtract in phase. The additive or “arrow” direction is assigned to the forward wave. The electrical values of the element circuits are carefully balanced and designed so that current from the reverse wave will cancel the other almost completely.
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Chapter 3 Installation The Model 4391A RF Power Analyst is completely portable and very suitable for field or laboratory use. Its power is derived from rechargeable nickel metal hydride batteries inside the unit or from an AC outlet via the power cord supplied with the device. The batteries are shipped in a low charge state. It is, therefore, recommended that you charge the instrument for 16 hours before using it for continuous operation.
Connections The Model 4391A contains a short section of rigid 50 ohm coaxial air dielectric transmission line. To make measurements relating to the travelling waves in a coaxial line, that line must be disconnected at some convenient point to permit the Model 4391A air line to be inserted. Although the Model 4391A is normally supplied with two Female N-type connectors, a variety of easily interchangeable connectors are available to facilitate connecting to the user’s system.
Chapter 4 Operating Instructions Operating Modes The Model 4391A has nine modes of operation which are selected by pressing the mode keys momentarily. In addition, each mode has three output options selected by pressing the modifier keys. Detailed descriptions of the modes and output options follow. Reading Forward CW Power For this measurement only a forward element is needed.
The Model 4391A arrives at values of CW power by a method quite different from analog meters such as the Model 43, also manufactured by Bird Electronic. While the two instruments will agree when the measured wave is of constant amplitude, AM or SSB waves will result in different indications (in the CW mode).
Table 2 Voltage Standing Wave Ratio (VSWR) VSWR Return Loss (dB) Reflected Power % VSWR 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.15 1.20 1.25 1.30 1.35 1.40 46.1 40.1 36.6 34.2 32.3 30.7 29.4 28.3 27.3 26.4 23.1 20.8 19.1 17.7 16.5 15.6 0.00 0.01 0.02 0.04 0.06 0.08 0.11 0.15 0.19 0.23 0.49 0.83 1.23 1.70 2.22 2.78 1.45 1.50 1.75 2.00 2.25 2.50 2.75 3.00 3.25 3.50 3.75 4.00 4.25 4.50 4.75 5.00 Return Reflected Loss (dB) Power % 14.7 14.0 11.3 9.50 8.30 7.40 6.60 6.00 5.50 5.10 4.70 4.
Measuring Amplitude Modulation Only a forward element is required for this mode. Point the element in the direction of forward power and press % MOD. Modulation is displayed directly in percent, provided the average signal is above 10% and the PEP of the signal is below 400% of the element’s nominal full scale. For specified accuracy, the average CW power levels must be greater than one-third of full scale.
Measuring Power in dBm Operation of the forward and reflected dBm modes is identical to the forward and reflected CW power modes, except that the resulting reading is converted to dB above 1 milliwatt before it is displayed. It should be noted that in doing this conversion, the range set on the slide switches is assumed to be watts rather than kilowatts or milliwatts. If it is not, 30.
Insertion Loss or Attenuation Attenuation or insertion loss can be measured directly using an external single port line section (P/N 4230-006-1), a dc feed-in adapter (P/N 4381-050), and a dc cable (P/N 3170-058-6). The Model 4391A is inserted at the source end of the device being measured. The second line section is inserted at the load end and its dc output is routed by the dc cable to the adapter inserted in the REFLECTED socket of the Model 4391A.
Figure 13 Maximum or Minimum Readings Using the Peaking Aid The peaking aid is useful for making adjustments to optimize any of the parameters which the Model 4391A measures. After the mode is selected, press the delta (Δ) key momentarily. This blanks the least significant digit of the display, and replaces it with a right-facing arrow head if the measured quantity is increasing or a left-facing arrow head if it is decreasing. If there is no change, the digit is left blank.
WARNING Use only Nickel Metal Hydride (NiMH) batteries that have a minimum capacity of 4500 milliamper hours (mAh). Do not install batteries that are not Nickel Metal Hydride. Do not install NiMH batteries that have less than 4500 mAh capacity. Failure to comply may result in damage to the batteries, damage to the instrument, and injury to personnel from battery chemicals. CAUTION Long-term storage of this instrument can affect battery performance and reduce battery life.
Chapter 5 Maintenance The 4391A RF Power Analyst was designed and built to provide many years of trouble free service. This section provides the information needed to prevent and correct equipment failure. Preventive Maintenance To avoid unnecessary damage, always observe the following cautions: CAUTION The RF Power Analyst is a rugged and portable instrument intended for field use. However, it should not be unnecessarily exposed to extreme environmental conditions.
• • Inspect the RF connectors for any sign of wear or damage. Replace if necessary. Clean the connectors with alcohol or any acceptable dry cleaning fluid. Long-term Storage Do not store the instrument for long periods of time without recharging the batteries. When the instrument is stored for long periods of time without use, the batteries will loose their charge and also loose the ability to reach full charge when put into service. To restore the battery charge, perform a full charge for 16 hours.
Initial Setup Note: On a clean flat workspace perform the following setup procedure: 1. 2. 3. Remove the front panel. Refer to "Front Panel Removal" on page 23. Insert a DC feed-in adapter into the FWD element of the socket. Insert a metal dust plug (supplied with the instrument) into the RFL element socket. 4. Connect a BNC to BNC cable assembly from the output of calibrator/source to the DC feed-in adapter. 5. Set the RF Power Analyst range switches to the 10 and x100 positions. 6.
Element Wiper Contact Adjustment CAUTION If the element cannot be fully inserted into the socket, do not force it. You might damage the element. CAUTION Be careful not to bend the spring out so far that it interferes with insertion of the elements. 1. 2. Note: Continuous insertion or rotation of the element might cause a slight change in the position of the contact spring in the element socket. If the contact spring changes position, you might experience erratic power readings.
Troubleshooting General The troubleshooting instructions are intended to aid in fault isolation. This is accomplished through the use of a troubleshooting table. First, locate the symptom(s) in the problem column of Table 7. In some cases the same fault can have more than one symptom and more than one possible remedy. Compare the possible causes until you arrive at a suspected fault. Once a fault has been isolated, repair or replace the defective components.
PROBLEM POSSIBLE CAUSE REMEDY Display indicates “0” Power Element wiper not contacting the element Readjust the element wiper to make good contact. Replace Plug-In Element. Replace the PC board assembly (attached to line section). Replace the display.
Front Panel Removal 1. 2. 3. 4. 5. Disconnect AC power from the instrument. Remove the six screws that secure the front panel to the Main PCB supports (Figure 18 on page 23, item 1). Remove the two screws and lock washers that secure the front panel at the bottom of the housing (item 2). Remove the two screws and lock washers that secure the front panel at the back of the housing (item 3). Lift the front panel from the housing. Note: Be careful to clear the line section blocks. 6.
Figure 19 Removing Main PCB QC Connectors Removal 1. 2. Remove the eight screws (four on each connector) that secure the connectors to the housing (Figure 20, item 1). Remove the two “QC” connectors (item 2) by pulling them away from the line section assembly. Line Section Removal 1. 2. 3. Remove the QC connectors (page 24). Remove the four screws and lock washers that secure line section assembly to the housing (item 3).
Figure 20 Removing QC Connectors and Line Section CAUTION This instrument contains static sensitive electronic components. Before opening or servicing the unit, make sure that you understand and practice electrostatic discharge component handling. Failure to comply may result in permanent damage to sensitive components. 4. 5. 6. 7. 8. 9. Remove the two hex nuts (Figure 21, item 5) that secure the PCB. Remove the cover (item 6) and spacers (item 7).
Figure 21 Removing Line Section PCB Battery Replacement 1. 2. Remove the front panel (refer to "Front Panel Removal" on page 23) . Remove the four screws and lock washers (Figure 22, item 1) that secure the Main PCB. 3. Loosen, but do not remove the remaining two screws that secure the Main PCB (item 2). 4. Tilt the Main PC board assembly up to expose the batteries then tighten the two screws to secure the PCB.
5. Unfasten the velcro strap and remove it from the D-ring. (Figure 23). 6. Remove the three battery tubes from the battery clips then remove two batteries from each tube. Install new batteries into the tubes then secure the tubes in the battery clips. Note: The polarity orientation of the batteries must reamin consistent. 7. Note: Be sure to observe proper polarity. 8. Lower and secure the Main PC board assembly 9. Replace and secure the front cover. 10.
Parts List This section contains an illustrated list of all authorized replacement parts for the 4391A RF power Analyst. Parts are grouped into major assemblies and subassemblies. Figure 24 Parts Drawing Item No. Description Part No.
Figure 25 Line Section Assembly (S/N 1723 & below) Item No. Description Part No. Qty Figure 25 N/A 1 Line Section, Subassembly 4381-005 1 2 PC Board, Data Acquisition Assy 4391A006 1 3 Bead, Keying 4391-026 2 4 Spacer 4391-027 2 5 Screw, Machine, filister head, No. 4-40, 1/4 in. lg, sst COML 2 6 Support 4381-029 2 7 Screw, Machine, filister head, No. 8-32, 1/2 in. lg, sst COML 4 8 Screw, Machine, filister head, No. 4-40, 7/8 in.
Figure 26 Line Section Assembly (S/N 1724 & above) Part No. Description Part No. Qty Figure 26 30 1 Line Section, Subassembly 4381-005 1 2 PC Board, Data Acquisition Assy 4391A006 1 3 Bead, Keying 4391-026 2 4 Spacer 4391-027 2 5 Screw, Machine, filister head, No. 4-40, 1/4 in. lg, sst COML 2 6 Support 4381-029 2 7 Screw, Machine, filister head, No. 8-32, 1/2 in. lg, sst COML 4 8 Hex Nut, with nylon insert, No.
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.
Specifications Measuring Medium RF Power Range* RF Transmission in 50 ohm lines 100 mW to 10 kW full scale using Bird Plug-in Elements. Accuracy not guaranteed with components not supplied by Bird To 120% of scale on CW, PEP, SWR, and Return loss Usable Overfunctions. To 400% of scale (PEP) on dBm and 0% Range* modulation. Frequency Range* 450 kHz to 2.
*. Frequency band and power range is determined by the Plug-in Elements selected. See Bird Catalog for availability. Some modes require two elements in a 10:1 power ratio. †. VSWR and return loss functions settle in less than 1 second. ‡. For CW power levels greater than one-third of full scale, accuracy of the percent modulation mode is 5% from 0 to 90% and +10% from 90 to 100%. Modulation frequency is 25 to 100,000 Hz; except for “A” and “B” elements: 25 to 20,000 Hz; and “H” elements: 25-10,000 Hz. **.
Bird Technologies 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.
