User manual MFJ 269 SWR

[. . . ] MFJ-269 Instruction Manual HF/VHF/UHF SWR Analyzer MFJ-269 SWR HF/VHF ANALYZER TABLE OF CONTENTS Warning: READ SECTION 2. 0 BEFORE ATTEMPTING TO USE THIS PRODUCT! INTRODUCTION 1. 0 DESCRIPTION MFJ-269 SWR HF/VHF ANALYZER TABLE OF CONTENTS Warning: READ SECTION 2. 0 BEFORE ATTEMPING TO USE THIS PRODUCT 1. 0 INTRODUCTION DESCRIPTION 1. 1 Typical Uses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1. 2 Frequency Range. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. 3 A Quick Word About Accuracy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3. 2. 0 POWER SOURCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. 1 External Power Supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. 2 Using Internal Batteries. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2. 2 Using Rechargeable AA Type Batteries. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2. 4 Using conventional AADrycell Batteries. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6. 2. 5 Blinking "VOLTAGE LOW" display warning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2. 6 "Power Saving Mode" (Sleep mode). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3. 0 MAIN MENU AND DISPLAY . . . . . . . . . . . [. . . ] The ANTENNA connector is not dc isolated from the load, external voltages will couple directly into internal detectors. Warning: Never apply external voltages or RF signals to the antenna connector. Keep leads as short as possible when measuring components or non-matched systems. Interconnecting transmission lines or wires can modify readings, including impedance and SWR. Use properly constructed coaxial cables of known quality matched to the analyzer impedance to avoid introducing SWR errors. 5. 4 Advanced 1 modes 19 MFJ-269 Instruction Manual HF/VHF/UHF SWR Analyzer Advanced 1 5. 4. 1 Advanced 1 (HF/VHF) ADVANCED 1 mode measures impedance and SWR functions. There are six display functions available in this mode: - Magnitude and phase of load impedance (5. 4. 1. 1) - Series Equivalent impedance (5. 4. 1. 2) - Parallel Equivalent impedance (5. 4. 1. 3) - Return loss and Reflection coefficient (5. 4. 1. 4) - Resonance (5. 4. 1. 5) - Match efficiency (5. 4. 1. 6) 5. 4. 1. 1 Magnitude and Phase of Load Impedance Magnitude and Phase of Impedance is the first mode in the advanced menu. The opening display first indicates: and then flashes to: In this mode, the MFJ-269 LCD displays frequency, impedance or Z magnitude (in ohms), and phase angle ( ) of impedance. The maximum impedance limit is set at 1500 ohms, exceeding the limit results in an impedance display of (Z>1500). Note: Stray connector capacitance will be lower than 1500 ohms at frequencies higher than 30 MHz, and lower as adapters and leads are added to the ANTENNA port. This small stray capacitance will not affect high frequency measurements, and produces only minor errors in measurement of impedances under a few hundred ohms at VHF. Instead of providing R and X as separate numerical quantities, a vector-type description of measured impedance is presented. Impedance (Z) is still described as the length (magnitude) of a line representing the complex impedance. (This is the same Z as given in other functions. ) Besides Z, an angle between zero and 90 degrees is shown. This angle represents the phase difference between current and voltage at the terminals of the analyzer. When a reactance is present, voltage and current are no longer in phase (or exactly out-of-phase) and so the phase angle increases from 0 degrees to a maximum angle of 90 degrees. The angle becomes 90 degrees when the load is a pure reactance, and zero degrees when the load is a pure resistance. 20 MFJ-269 Instruction Manual HF/VHF/UHF SWR Analyzer This analyzer will determine the angle in degrees, but it will not describe the load reactance specifically as either capacitive or inductive. It is a simple matter to determine the direction by adding a small amount of reactance in series with the load and watching the angle change. If the angle decreases, the load reactance is opposite to the sign or type of test reactance. If the angle increases, the load reactance is the same sign as the added reactance. 5. 4. 1. 2 Series Equivalent Impedance This "ADVANCED 1" display sub-mode is reached by pressing the GATE button once while in the "Magnitude and Phase of Load Impedance" mode. This is the most common form used to describe antenna system impedance. In this mode, the load impedance is described as a resistance in series with a reactance. In order to cancel the reactance without changing the resistance, a reactance of the opposite type and same reactance value must be connected in series with the load at the point of measurement. The digital display shows SWR, resistive part of load impedance (Rs=), and reactive part of load impedance (Xs=). [. . . ] Voltage and current balun test: 38 MFJ-269 Instruction Manual HF/VHF/UHF SWR Analyzer To the MFJ-259B's "ANTENNA" connector Clip Lead A BALUN C B A properly designed current balun is the type most effective for maintaining current balance. It has the highest power capability and lowest loss for given materials. It should show a low SWR over the entire operating range of the balun with the clip lead in any of the three positions. A well designed voltage balun should show a low SWR over the entire operating range when the clip lead is in position "B". [. . . ]