TM-9-2350-275-BD Battlefield Damage Assessment and Repair for M113 Family Download
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TM 9-2350-275-BD COMMUNICATIONS SYSTEM Procedural Steps (Cont): i. Check the power supply in the receive mode by noting the reading on the INDICATOR METER (12) and turning the VOLTAGE CHECK/OPERATE SWITCH (28) clockwise to the 6,3B and the 150B positions. The needle on the INDICATOR METER (12) should be in the shaded portion of the scale for all readings. If not in the shaded portion, check the power supply for bad fuses and replace any bad ones. CAUTION The receiver and transmitter are tuned simultaneously. Do not operate the transmitter without using an antenna or dummy load. Transmitting into an antenna base without connecting an antenna may damage the transmitter portion of the radio. j. Check the power supply in the transmit mode by placing the VOLTAGE CHECK/OPERATE SWITCH (28) to the 1,2B position on the transmitter circuits portion of the scale (approximate y the 7 o'clock position). The INDICATOR METER (12) should read in the shaded portion of the scale. If not in the shaded portion, check the power supply for bad fuses and replace any bad ones. k. Place the VOLTAGE CHECK/OPERATE SWITCH (28) in the 150B position by rotating the switch clockwise. Momentarily place the chest plate switch and the CVC helmet or H-189 switch in the transmit position. Note the reading on the INDIATOR METER (12); it should be in the shaded portion of the scale. Release the switches. l. Place the VOLTAGE CHECK/OPERATE SWITCH (28) alternately in the 250B and 600B positions by rotating the switch clockwise. To obtain an indication, it is necessary to momentarily depress the switches to transmit. Both the readings should be in the shaded portion of the scale. m. Place the VOLTAGE CHECK/OPERATE SWITCH (28) in the operate #1 PABOTA 1) position. n. Place the PRESET CHANNEL/CONTINUOUS TUNE SELECTOR SWITCH (18) in either the I or 11 position. Position I will be used if the desired operating frequency is between 20 and 35.75 MHZ and position II will be selected if the desired operating frequency will be between 35.8 to 51.5 MHZ. Band selections are also shown by the BAND INDICATOR (13) lights. To calibrate the FREQUENCY DIAL, rotate the FREQUENCY TUNING KNOB (27) while looking into the FREQUENCY DIAL VIEWING WINDOW (5) and select the frequency listed below that is the closest to the desired operating frequency. Band I: 22.050 MHZ 28.350 MHZ 34.650 MHZ Band II: 36.225 MHZ 40.950 MHZ 42.525 MHZ 45.675 MHZ 48.825 MHZ The frequencies are noted on the frequency dial with an extended graduation line capped by an arrowhead. 11-34