RF Directional Thruline® Wattmeter Model 43 Also Covers Models 4431, 43P And Series 4300 and 4520 OPERATING INSTRUCTIONS ©Copyright 2011 by Bird Electronic Corporation Instruction Book Part Number 920-43 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.
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 Handle elements with care. Calibration could be disturbed if they are dropped. On page 11. CAUTION Do not attempt to remove the RF center conductor. This will damage the line section. On page 20.
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.
WARTUNG ANWEISUNGEN FÜR DIE WARTUNG DES GERÄTES GELTEN NUR FÜR GESCHULTES FACHPERSONAL. ZUR VERMEIDUNG GEFÄHRLICHE, ELEKTRISCHE SCHOCKS, SIND 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.
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: 43 43P 4301 4521 4522 4526 4305A 4431 4527 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.
Table of Contents Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii Safety Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv Warning Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv Caution Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv Safety Statements . . . . . . . . . . . . . . .
Zero Adjust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Customer Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bird 43 Replacement Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bird 43 Replacement Parts List . . . . . . . . . . . . . . . . .
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Chapter 1 Introduction Purpose and Function The 43 is an insertion-type RF wattmeter, designed to measure RF power and load match in 50 ohm coaxial transmission lines. It is intended for use with CW, AM, FM, and TV modulation, but not pulse modulation. When used in 50 ohm applications, the 43 has a maximum VSWR of 1.05 for frequencies up to 1000 MHz. The meter provides direct readings in watts with an expanded scale for easy reading. The scale is graduated for 25, 50, and 100 full scale.
Figure 1 Securing an element Contacts on opposite sides of the element connect with the spring finger when the element is in the forward or reverse position. This occurs when the stop pin on the element is against either stop and the catch is in place.
Chapter 2 Theory of Operation Travelling Wave Viewpoint The easiest way to visualize Thruline operation is from a travelling wave viewpoint. In transmission lines the voltages, currents, standing waves, etc., on any uniform line section result from the interaction of two travelling waves: • • Forward Wave (and its power) travels from the source to the load. It has RF voltage Ef and current If in phase, with Ef / If = Zo.
Figure 3 Thruline Wattmeter Schematic Current is produced in the coupling circuit by the travelling waves in the line section. Both inductive and capacitive coupling contribute to this. The inductive current flows in the direction of the travelling wave. The capacitive current is independent of the direction of the travelling wave.
Standing Wave vs. Travelling Wave Viewpoint (ρ vs. φ) As mentioned previously, the Thruline Wattmeter reacts to forward and reverse travelling waves to measure power in a transmission line. The standing wave viewpoint, also widely used, is highly developed both in theory and in practice. This viewpoint can be traced to the early use of slotted transmission lines.
Figure 4 6 Percent Reflected Power vs. VSWR (1.0 – 1.
Figure 5 Percent Reflected Power vs. VSWR (1.0 – 8.0) Low Reflection Measurements φ = 10% (ρ = 2) is the typical limit of antenna match. Further effort is frequently not worthwhile because below this level reflected power is hard to measure, and Wl can not be significantly increased. TV and VHF transmitters are examples of systems requiring lower reflected power but for reasons other than maximizing power transmission.
When the same element is used to measure both forward and reflected power, meaningful readings are possible down to about φ = 5% (ρ = 1.5). For accurate measurement of very low levels of reflected power, i.e. φ = 0.6% (ρ = 1.17), use a second element rated at one tenth of the full scale power of the forward element. This method should not be used with element ranges differing by more than 10:1. Example - Consider an 80 watt transmitter and a Bird 43 with 100 and 10 watt elements.
Measuring Insertion Loss 1. 2. 3. Check forward and reverse power equality with a high quality open circuit, Connect an open-circuited, unknown line to the wattmeter. Measure the line twice (once down and once back). Note: The measured φ is the attenuation for two passes along the line. 4. Compare the attenuation with published data for line type and length (remember to halve Ndb or double the line length to account for the measurement technique).
These curves are typical for all element types (H, A, B, C, D, ...) at their respective frequencies. Since a C type element has a frequency range of 100 - 250 MHz, response curves for other element types can be approximated by replacing the 100 and 250 MHz points on the chart with the extremes of the element’s frequency range, and recalc-ulating the other frequency points accordingly. Example - For a B element (range 50 - 125 MHz) simply divide all frequencies by two.
Chapter 3 Installation When transporting the Bird 43, insert the original dust plug, or an element with the arrow pointing upward, in the element socket and secure with the catch. This will shunt the meter circuit and protect the meter by dampening needle action during handling and shipping. Also, secure spare elements in their sockets with the pivoting knob; just insert the element and twist the knob one-quarter turn. CAUTION Handle elements with care. Calibration could be disturbed if they are dropped.
Remote Installation 1. 2. 3. 4. Note: To replace the RF line section, reverse these steps. Unscrew the four 8-32 flat head screws securing the back cover. Grasp the back cover by the side tabs behind the line connectors and pull straight back to remove it. Remove the two 10-32 oval screws on the front of the housing. Slide the line section out of the housing. Note: Do not loosen the two oval screws on the sides of the housing in line with the meter. These hold the shock ring in place. 5.
Chapter 4 Operating Instructions WARNING When working with RF powers of 200 watts or more, the potential of the center conductor of the line section will exceed 100 volts. Do not touch the center conductor while RF power is on. The Bird 43 uses plug-in elements to make measurements. The element’s frequency range and maximum power are listed on its label. The transmitter test frequency should be within the band of the element used.
Figure 8 Element Direction When readings are being made with the wattmeter connected to an auxiliary RF line section, do not put an element in the unused line section. Otherwise, the DC circuit will be unbalanced or shorted, causing inaccurate or zero power readings. For convenience, a set of VSWR conversion nomographs is included in this manual. With these charts, VSWR may be determined from the forward and reflected power readings. Find the intersection of the forward and reflected power measurements.
Figure 9 VSWR Conversion Graph (Reflected Power 0.2 – 20.
Figure 10 16 VSWR Conversion Graph (Reflected Power 0.01 – 1.
Load Matching When a Bird 43 is used to tune a load to a transmitter and a good match is obtained, removing the unit will not change the match quality. A good 50 ohm load can terminate a 50 ohm transmission line of any length without altering conditions at the transmitter. The 43 is just an extra length of 50 ohm line in series with the measurement. When the load is not well matched (an antenna with a VSWR of 1.5 or 2.
Figure 11 18 Cable Length / Wavelength Matching
Chapter 5 Maintenance The rugged and simple design of the Bird 43 means that it requires minimal routine maintenance. Troublehshooting The following table contains troubleshooting information for problems that can occur during normal operation. Find the problem on the table, review possible causes, and perform the corrective action listed. This manual does not list all malfunctions that may occur, or all corrective actions.
Cleaning It is important to keep the following surfaces clean: • • • Socket bore DC contacts on the element Teflon insulators If any of the contacts or line connectors are dirty, clean them with a cotton swab dipped in commercial contact cleaner or isopropyl alcohol. CAUTION Do not attempt to remove the RF center conductor. This will damage the line section. If the RF line section seems dirty, do not loosen any connections.
Zero Adjust The meter’s zero setting should be checked when no RF power is present. When no power is applied the pointer should rest exactly on zero. If adjustment is required, turn the adjustment screw until the pointer is set at zero (see Figure 12). Figure 12 Zero Adjust Storage When storing the meter, keep an element or dust plug in the element socket to prevent the intrusion of dust and to prevent damage to the meter movement. When using an element, use the highest power element available.
Customer Service Any maintenance or service procedure beyond the scope of those in this chapter should be referred to a qualified service center. If the unit needs to be returned for any reason, request an RMA through the Bird Technologies website. 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.
Bird 43 Replacement Parts List Note: See “Customer Replacement Parts” on page 32 Description Qty.
Customer Replacement Part RPK43-5 - External Hardware Kit Consists of 1118-0614-00 1120-0820-00 1136-0813-00 5-1388 5-1763 8240-054 8580A003 923-RPK43-5 24 Description #8-32x3/8 Phillips Flathead Machine Screw #10-32x1/2 Phillips Oval Screw #10-32x1/2 Phillips Pan Screw Rubber Bumper Stem Gray Rubber Bumper Foot Strap Spacer Screw Plastic Handle Instruction Sheet
Available “QC” Type Connectors Connector Part Number Connector Part Number BNC-Female 4240-125 Open Term.
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Chapter 6 Model Differences Bird 43P Peak Wattmeter The Bird 43P Thruline Wattmeter is the same as the Bird 43, with the added capability of measuring peak power in AM, SSB, and some pulse applications. A conversion kit (P/N 4300-400) is available to give peak reading capability to any standard Bird 43. This kit comes with all necessary parts and easy to follow instructions for simple and quick conversion. Special elements are not required.
Peak Calibration If recalibration is required, refer to figure 15 and these instructions: 1. Unscrew the four 8-32 flat head screws securing the back cover. 2. Grasp the back cover by the side tabs behind the line connectors and pull straight back to remove it. 3. Insert the Bird 43P between a reliable CW signal source and a 50 ohm load. 4. Insert an element with the appropriate power and frequency range into the Bird 43P. Turn it to read forward power. 5. Set the wattmeter to CW mode (LED off). 6.
Bird 4301 Thruline Wattmeter The Bird 4301 Thruline Wattmeter is the same as the Bird 43 except for the following physical differences: The auxiliary DC connector on the Model 4301 can be used to connect to an accessory line section. Make the connection with a standard RG-58/U cable.
Bird 4305A Replacement Parts List Customer Replacement Part RPK4305-1 - Housing Kit RPK4305-2 - Rear Cover Kit RPK4305-3 - Line Section Kit RPK4305-4 - Meter Kit RPK4305-5- External Hardware Kit Consists of 4305A003 RPK4305-5 923-RPK4305-1 4305A002 1118-0419-00 923-RPK4305-2 4305-005 923-RPK4305-3 2150A015-1 4220-097-22 923-RPK4305-4 1116-0400-00 1120-0819-00 4285-002-4 923-RPK4305-5 30 Description Housing, Meter Assembly External Hardware Kit Instruction Sheet Cover Assembly #8-32x1/4 Phillips Screw
Bird 4431 Thruline Wattmeter The Bird 4431 RF Sampling Wattmeter is the same as the Bird 43 Thruline Wattmeter except for an RF signal sampler probe. The RF sampler provides a low power sample of the signal being transmitted through the wattmeter’s linesection. This signal is available at the female BNC connector labeled “RF SAMPLE”, on the right side of the housing. The signal level can be set with the control knob on the front of the meter.
4. 5. 6. 7. 8. Remove the two 8-32 x 1/4” screws fastening the guide and plate assembly to the back of the line section. Put the control knob back on the shaft, then turn it counterclock-wise until the collar is free of the shaft. Remove the control knob. Pull the probe plate straight out of the pin and guide bushing. Unscrew the 5/8 hex nut on the BNC connector and pull the sampler connector into the case. The probe plate assembly, P/N 4431-003, is now released and may be replaced.
Customer Replacement Part RPK4431-4 - External Hardware Kit Consists of Description 8580A003 5-1388 5-1763 1120-0820-00 1118-0614-00 1138-0813-00 4431-035 8240-054 5-1193 923-RPK4431-4 Handle, Plastic Bumper, Stem Rubber Bumper Ft, Gray Rubber #10-32x1/2 Phil Screws #8-32x3/8 Phil Screws #10-32x1/2 Phil Screws Label, RF Sample Spacer, Strap, Screw Knob, Knurled BLK Instruction Sheet Service Only Replacement Parts Replacement Part RP3610-031 RP2080-002 RP4300-015 RP5-1388 Consists of 3610-031 (5 per) 2
Bird 4520 Series Replacement Parts List The mounting panel entry lists the panel styles for each model. Only parts which are not used on the Bird 43 are listed here.
Customer Replacement Part RPK4522-3- External Hardware Kit Consists of 1116-0801-25 1132-0201-00 1131-0200-00 1120-0820-00 1132-0406-00 5A2315-2 1131-0400-00 5A2290-2 5A2290-1 923-RPK4522-3 4522-006 5A2290-2 5A2290-1 923-RPK4522-4 RPK4522-4 - Front Panel Kit Description #6-32x1/2 Round MS Screw #6 Split Lock Washer #6-32 Hex Nut SS #10-32x1/2 Phillips Screws #10 External Lock Washer Label, Safety Symbol #10-32 Hex Nut SS Label, RFL Label, FWD Instruction Sheet Panel, Mounting Label, RFL Label, FWD Instru
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Chapter 7 Specifications These specifications include data covering the Bird 43, 43P, 4305A, 4431, 4521, 4522, 4526, and 4527. Specifications for models not listed are identical to the Bird 43. Impedance, Nominal 50 ohm VSWR, Max. All models except 4431 4431 1.05:1 1.07:1 (when coupling is less than 30 dB) Connectors Primary Line RF Sampling (on applicable models) Bird “QC” (N Female normally supplied) Female BNC Power and Frequency Range (element dependent) 43,43P,4521/22/26 100 mW – 10 kW 0.
Approximate Weight with N-Connectors 4521/22/26/27 43, 43P, 4431 4305A Operating Position Finish 3 lb. (1.36 kg) 4 lb. (1.8 kg) 3.43 lb. (1.6 kg) Any Grey Powder Coat *. Applicable only for maximum coupling less than 30 dB.
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.
