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X. RF Threshold Test <br />Description <br />A TRUE COPY <br />CERTIFICATION ON LAST PAGE <br />RYAN L. SUTLER, CLERK <br />The purpose of this test is to measure the Receive Signal Level for threshold of 10E-6 by fading the TX <br />RF. <br />A variable attenuator is inserted between the Terminal RF Out and the Transmission Line in order to <br />simulate a fade, i.e. reducing the Receive Signal Level (RSL) at the coordinating receiver. Please refer to <br />the pathloss system report for RSL levels and RX threshold levels. <br />Instructions <br />1. Log on to the Terminal under test if you have not already logged on. <br />a. Connect a PC with the EM2 software installed via the serial connector on the front of the <br />terminal labeled "COMPUTER". <br />b. Open the EM2 software and on the initial log -in screen select "Serial" from the pull down <br />and choose the appropriate "COM PORT" that the PC is using. <br />c. Enter the username: "admin" (note this cannot be changed) enter the password. The default <br />password is "password" which can be changed). Once the correct "admin" and "User <br />password" is entered you will be "logged on" and the displayed terminal icons will go from <br />gray to yellow to indicate communication with the terminal under test. <br />2. The System Test Data Sheet provided from the MNI factory will have an AGC to RSL curve on it <br />that will be used to verify this test. From that curve ensure that the RSL specification above is met. <br />Each terminal has a slightly different voltage curve. <br />3. Use the G.826 internal BER counter of the MNI EM2 software to determine threshold point of each <br />Receive path. <br />4. In the EM2 software go to the "Test" and "RFU Mute" selection and MUTE all the RF portions of <br />the terminal. Set the time to be "0" so it does not UN -Mute. <br />5. In the EM2 software Go to "Configuration" then "RFU" and click on "ATPC Enable" (toggle). <br />"ATPC Off' will be displayed and hit Apply. <br />Warning — In the field DO NOT Mute the Far End terminal unless you set a time out. You will lose <br />communication to that terminal which can only be un -muted by logging on locally. <br />6. Disconnect the RF connection at the waveguide flange of the terminal and insert a variable <br />attenuator in line with the coordinating terminal. FADE TO THRESHOLD TEST <br />a. Set the variable attenuator to "OdB" and connect a Power Meter to the "output" of the <br />RF cable that connects to the Receiver under test. <br />b. In the EM2 software Go back to the "Test" then "RFU Mute" screen and set the terminal <br />to "ONLINE". <br />c. Connect a Digital Voltmeter to the AGC port on the coordinating receiver. <br />d. Slowly set the Variable attenuator to the value needed to achieve 10E-6 BER. <br />e. Write down the result <br />Page 23 o <br />