Table of contents 1. Description ....................3 2. Specifications ....................4 3. Precautions ....................5 4. Operation...................... 6 4.1. Preparation for use ................. 6 4.2. Turning the analyzer on or off ..............6 4.3. Main menu ..................... 7 4.4. Single- and multi-point measurement modes.......... 7 4.4.1.
1. Description RigExpert AA-30 and AA-54 are powerful antenna analyzers designed for testing, checking, tuning or repairing antennas and antenna feedlines. Graphical SWR (Standing Wave Ratio) and impedance display are key features of these analyzers which significantly reduce the time required to adjust an antenna.
2. Specifications Frequency range: AA-30: 0.1 to 30 MHz, AA-54: 0.1 to 54 MHz Frequency entry: 1 kHz resolution SWR measurement range: 1 to 10 SWR measurement for 50 and 75-Ohm systems SWR display: numerical or easily-readable bar R and X range: 0…1000, -1000…1000 in numerical mode, 0…200, -200…200 in graph mode...
3. Precautions Never connect the analyzer to your antenna in thunderstorms. Lightning strikes as well as static discharge may kill the operator. Never leave the analyzer connected to your antenna after you finished operating it. Occasional lightning strikes or nearby transmitters may permanently damage it.
The on-screen menu system of RigExpert antenna analyzers provides a simple but effective way to control the entire device. Since capabilities of AA-30 and AA-54 are different, menus of these analyzers are also slightly different. When needed, screen shots of both analyzer types are shown...
• The USB icon is displayed when the analyzer is plugged to a personal computer or to a DC adapter with USB socket. RigExpert antenna analyzers are self-documenting: pressing the key will bring a help screen with a list of available keys for the current mode.
Pressing the key will show a list of other commands. 4.4.2. MultiSWR mode (AA-54 only) RigExpert AA-54 has an ability to display SWR for up to five different frequencies at a time. Numerical display Bars You may use this feature to tune multi-band antennas.
• In the parallel model, impedance is expressed as resistance and reactance connected in parallel: 4.5. Graph modes A key feature of RigExpert antenna analyzers is ability to display various parameters of a load graphically. Graphs are especially useful to view the behavior of these parameters over the specified frequency band.
4.5.1. SWR graph In the SWR graph mode (press the key in the Main menu), values of the Standing Wave Ratio are plotted over the specified frequency range: You may set the center frequency (the key) or scanning range (the key).
4.6. Settings menu The Settings menu (press the key in the Main menu) contains various settings for the analyzer. The first page contains the following commands: AA-30 AA-54 – language selection (AA-54 only); – backlight on or off; – sound on or off;...
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– RF bridge test. With no load at the antenna connector, the display should look like shown on the picture: For the 50-Ohm load, the filled bars should stand at corresponding positions (notice the “no load” and “50 ” marks): If the bars are not filled at all, the RF output stage or/and the detector are not working properly in the analyzer.
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– detector output voltage vs. frequency graph. With no load at the antenna connector, the display should look like shown on the picture: AA-30 AA-54 The voltage curve should stay between the horizontal dotted lines. The vertical lines are the bounds of analyzer’s subbands.
– go to the first page of settings. 4.7. Computer connection RigExpert antenna analyzers may be connected to a personal computer for displaying measurement results on its screen, taking screen shots of the LCD, as well as for updating the firmware.
5. Applications 5.1. Antennas 5.1.1. Checking the antenna It is a good idea to check an antenna before connecting it to the receiving or transmitting equipment. The SWR graph mode is good for this purpose: The above picture shows SWR graph of an HF antenna. The operating frequency is 7.1 MHz.
Physical dimensions of a simple antenna (such as a dipole) can be adjusted knowing the actual resonant frequency and the desired one. Other types of antennas may contain more than one element to adjust (including coils, filters, etc.), so this method will not work. Instead, you may use the SWR mode or the Show all mode to continuously see the results while adjusting various parameters of the antenna.
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Each type of cable has different velocity factor: for instance, for RG-58 it is 0.66. Notice that this parameter may vary depending on the manufacturing process and materials the cable is made of. To measure the physical length of a cable, 1.
5.2.3. Velocity factor measurement For a known resonant frequency and physical length of a cable, the actual value of the velocity factor can be easily measured: 1. Locate a resonant frequency as described above. Example: 10.09 meters (33.10 feet) of open-circuited cable. Resonant frequency is 4835 kHz at the 1/4-wave point.
5.2.5. Making 1/4-λ, 1/2-λ and other coaxial stubs Pieces of cable of certain electrical length are often used as components of baluns (balancing units), transmission line transformers or delay lines. To make a stub of the predetermined electrical length, 1. Calculate the physical length. Divide the electromagnetic constant by the required frequency (in Hz).
5.2.6. Measuring the characteristic impedance The characteristic impedance is one of the main parameters of any coaxial cable. Usually, its value is printed on the cable by the manufacturer. However, in certain cases the exact value of the characteristic impedance is unknown or is in question. To measure the characteristic impedance of a cable, 1.
Example 2: sqrt (75.2 · 52.1) = 62.6 Ohm 5.3. Measurement of other elements Although RigExpert antenna analyzers are designed for use with antennas and antenna- feeder paths, they may be successfully used to measure parameters of other RF elements.
5.4. RF signal generator The output signal of AA-30 and AA-54 has rectangular waveform and level of about +13 dBm (at the 50 Ohm load). Therefore these analyzers can be used as sources of RF signal for various purposes.
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