AIM Quick Start

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//-->AIM Quick Start GuideSept 26, 2011LOADING THE SOFTWARE:The AIMuhf/AIM4170/PowerAIM software does not require a formal installationprocedure. It does not interfere with any other programs or the registry on your computer.1) Create a folder or a subfolder on any convenient hard drive.For example, “C:\AntennaAnalyzer”. (the name can be anything)2) Download the latest program from the website:http://www.w5big.com/prog_update.htmThe latest program is shown at the top of the page.3) Save the zip file in the folder you just created for the antenna analyzer software anddocumentation. Unzip it in this folder or another folder if you wish.4) The file labeled “AIM_xxx.exe” is the executable file. It is ready to run without goingthrough an installation process. When later versions of the program are released, thenumber “_xxx” will be different. All versions of the antenna analyzer program can residein the same folder at the same time. The older programs with the lower numbers will notinterfere with the newest version, so they do not have to be deleted.Be sure your computer displays theextensions of filesso you can distinguish the *.exefiles from the other files. See Appendix 5 for more information.5) The same program will run theAIMuhf,theAIM4170and thePowerAIM.Itautomatically determines which instrument is connected when it starts to run. It isimportant to turn on the hardware before starting the program.If you want to make a shortcut icon for your desktop, right click on the AIM_xxx.exe file(or the latest version) and select “create shortcut” from the dropdown menu. Drag theshortcut to your desktop or task bar.HARDWARE CONNECTIONS:Plug in the DC power supply (8 to 12V at 500 ma recommended) and insert the connectorinto the jack on the rear panel of the analyzer.Press the power switch. The Green LED will blink a few times to indicate the version ofsoftware and then remain on continuously. The Red LED is on only when a measurementis in progress.1To turn off the power, press the power switch again. If the analyzer does not receive acommand from the PC for 10 minutes, it will power down automatically if it is in theAutoPwrOff mode. The AutoPwrOff mode can be turned on/off with a menu selectionunder theSetuptab at the top of the screen.The AIMuhf/AIM4170 can be operated on battery power for remote operation with alaptop computer. The current required is about 350-400ma while a measurement is inprogress and about 50ma when idle.Batteries are not included with the AIMuhf/AIM4170 but you can make a battery packusing any type of batteries you like. There is roominside the casefor a 9V battery anddisconnect diodes are included so the battery and the AC power supply will not interferewith each other. There is also a space for an optional resistor to use for trickle charging abattery, if desired. The main power on/off switch controls the battery power too, so theleakage current is less than one microamp when the AIMuhf/AIM4170 is turned off.Refer to Appendix 6 and the Application-Help file for more detailsWhen using the AIMuhf/AIM4170 to test a mobile antenna on a motor vehicle, it is betterto use a separate battery andnotthe 12V battery in the vehicle. A 9V battery will powerthe unit for several hours or a small 12V gel cell (sealed lead acid) battery can be used forextended operating periods. This avoids the problem of sneak paths through the groundbetween the DC power input and the antenna ground connection. It will also help reducemeasurement noise if it’s necessary to run the engine while taking data (such as tooperate the air conditioner).If it’s essential to get power for the AIMuhf/AIM4170from the vehicle, be sure to put 500 ma fuses in BOTH the +12V lead and the powerground lead.A small voltage drop across the fuses will not affect the AIMuhf/AIM4170since the battery voltage is much more than the required minimum operating voltage.The laptop computer being used should remainfloatingfor the best measurementaccuracy.When using the AIMuhf/AIM4170 with a new antenna system, check the AC and DCvoltage between the antenna ground and the ground used for the AIMuhf/AIM4170 andthe PC. This voltage should be less than 1V. A balanced antenna should have a DCconnection to ground through a balun or RF choke on one side (or both sides). Of coursethere should always be a large resistor (or balun) connecting both leads of the antenna toa ground path in order to drain off static electricity.NOTE: Before connecting a transmission line to the input of theAIMuhf/AIM4170, be sure to momentarily short its pins together to drainoff any static charge that may be present. Also, be sure there is no DCvoltage on the antenna. If there is DC, use a blocking capacitor between theAIMuhf/AIM4170 and the antenna input.Antennas and transmission lines can have enough static charge to damage sensitiveelectronic equipment. This can happen even when there is no rainstorm in the area.2A strong wind can generate static charge. So can just flexing a coaxial cable byrolling it up or unrolling it, even if there is no antenna connected to it.An antenna or a component to be measured should not be connected ordisconnected from the analyzer while a test is in progress. A test is in progress whentheRED LEDis on.Be sure the maximum input voltage at the DC power connector does notexceed 15 volts. The minimum input voltage required is 6.0 volts.NOTE:Low cost power supplies that plug in the wall are usually not regulated and theirmaximum output when no load is connected may be several volts higher than their ratedoutput.Check the output voltage with no load to make sure it does not exceed 15volts.Power supplies that operate on a wide input voltage range such as 120V to 220V use aswitching regulator. Evaluate the measurement results to see if noise from the powersupply may be a problem.PC INTERFACE CABLE:Connect one end of theRS232 cableto the antenna analyzer and the other end to COM1on your PC. If you want to use a different COMM port, start the AIMuhf/AIM4170program and click on theSetupmenu at the top of the screen. Then click onEnterComm Portand enter the port number that you want to use. This number will be savedin the setup file calledAIM_xxx.ini.If you are connecting to the RS232 port with a USB adapter, you will need theappropriate driver. An adapter based on the FTDI chip is recommended, especially withWin 7. For additional information on the usb port, refer to this document:w5big.com/PC_USB_INTERFACE.pdfIf you have a USB adapter that you have been using, it should be ready to run.3Initial Operation:Launch the AIM_xxx.exe program. You will see a graph similar to this:When the AIMuhf/AIM4170 is present, it must be turned onbeforethe PC program islaunched.If the PC program starts when the AIMuhf/AIM4170 is not connected and powered up,the program will automatically enter the DEMO mode. In the demo mode, you can lookat previously saved scan files.For a quick test after calibrating, leave the calibration resistor connected to the RFconnector and click theSCANbutton in the lower left corner of the screen.The Red LED will come on while the scan is in progress. A blue bar will move across thetop of the graph as the scan progresses.You will see a set of traces (similar to the picture below). The actual values are notimportant, but this shows the AIMuhf/AIM4170 is functioning.4Scan using a 301 ohm resistor for a test load.5 [ Pobierz całość w formacie PDF ]