TM-9-1290-365-24&P Technical and Parts Manual for Paladin Muzzle Velocity System M93 Upgraded Download
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ARMY TM 9-1290-365-24&P (6) Connect the RMS voltmeter input to the VIDEO[-] output on the test fixture. (7) Verify the noise level in mV: 100mVrms to 300mVrms. c. 50KHz Sensitivity Test. Record the test results on the test data sheet (Table D-5) under the 50KHz section of the sensitivity test. (1) Disconnect the RMS voltmeter from the test fixture. Connect both channels of the oscilloscope to the VIDEO[+] and VIDEO[-] output on the test fixture. (2) Decrease the attenuation of the variable attenuator until the signal on both channels is saturated. Verify the signal voltage level on CH1: VSAT[+] = 13Vp-p minimum. (3) Verify the signal voltage level on CH2: VSAT[-] = 13Vp-p minimum and is reverse polarity to CH1 on the oscilloscope. (4) Set the variable attenuator to 30dBm. (5) Disconnect both channels of the oscilloscope from the test fixture. (6) Connect the RMS voltmeter input to the VIDEO[+] output on the test fixture. (7) Record the noise level in dBm. (8) Decrease the attenuation until the voltage level that is measured on the VIDEO[+] output is 3±0.3dB above the noise level measured in step (7). Record the RMS signal level in dBm. NOTE Adjust the phase shifter on the microwave test fixture to get the maximum signal on the RMS voltmeter. (9) Record the attenuation of the variable attenuator. Set the variable attenuator to 30dB. (10) Disconnect the RMS voltmeter from the VIDEO[+] output and connect it to VIDEO[-] output on the test fixture. Record the noise level in dBm. (11) Decrease the attenuation until the Voltage level that is measured on the VIDEO[-] output is 3±0.3dB above the noise level measured in step (10). Record the RMS signal level in dBm. (12) Record the attenuation of the variable attenuator. (13 ) Calculate the receiver sensitivity of VIDEO[+] output (see note): S[+] = -1O6dBm maximum. (14) Calculate the receiver sensitivity of VIDEO[-] output (see note): S[-] = -1O6dBm maximum NOTE: Sensitivity calculation S = PT(dBm) - KS - 2A where: S - Receiver Sensitivity in dBm PT(dBm) - Transmitted Power in dBm as was calculated in para. KS - Sensitivity calibration factor as indicated on the directional coupler. A - Attenuation of the variable attenuator as measured in step (9) (VIDEO[+]) and step (12) (VIDEO[ -]). d. 10KHZ Sensitivity Test. Record test results on the test data sheet (Table D-5) under the 10KHz section of the sensitivity test. (1) Set the function generator to 10KHz ±100Hz. (2) Repeat steps D.4.12.2.6c.(1) to d.(14). D-35