Military

(1) Default entry. Press the SET UP switch. The MBC displays the menu for setup data: timeout, target prefix, target number block, grid declination, message transmission rate, transmitter warm-up delay time, transmission single or double block mode, and owner identification.

(2) Correction entry. Select the blue display switch beneath the flashing cursor in the display window. The display shows: 15 30 45 60. There are flashing cursors on each number. The four blue display switches interact with the display directly above them--for example, if the switches were numbered from left to right 1, 2, 3, and 4, and the timeout is to be changed (corrected) to 60 seconds, select the number 4 display switch. The computer now shows TIME OUT: 60.

(3) Alphabetical entry. The target number block assigned to the mortar platoon is AH0001 - AH0099. Use the keyboard to enter the target prefix, which is entered in the underlined blanks. The target prefix is AH.

(4) Numerical entry. After the sequence switch is selected to store the target prefix, the display screen asks for the numerical half of the target block number: 0001 - 0099. The display shows: TN:_ _ _ _ - _ _ _ _. To make the numeric entry--

(5) Correction entry. If the sequence key is pressed before making the correction entry, simply press the BACK key to bring the last screen information "back" on.

(6) Minimum easting and minimum northing entries. The next two displays, MIN E:_ _ _ 0 0 0 and MIN N:_ _ _ 0 0 0, are entered with numerical selections. The minimum easting (MIN E) and the minimum northing (MIN N) are the coordinates at the lower left corner of a map sheet. Each of these coordinates are entered into the MBC preceded by a 0--for example, the grid intersection of a map sheet (lower left corner) is 50/89. The MIN E is entered into the computer as 050, and the MIN N is entered as 089. The three trailing zeros are computer-entered for each display.

(7) Direction entry (display-selectable). Select the sequence switch and the display shows: E W GD:_ _ _. This display is one example of a direction entry with an amount. East (E) or west (W) must be selected from the display before filling in the underlined blanks for grid declination.

(8) Multiple choice entry. The keytone is the length of time required for a communications device (FM radio) to enable the transmitter before sending data. When a radio is hot from frequent use, it takes a lower keytone to send a message. Similarly, if the radio is cold from the outside temperature, it takes longer to send a message. The normal or default value is 1.4 seconds. For this example, change the keytone to 3.5 seconds as follows:

(1) Press the ON/OFF switch; the MBC shows: POWERUP TEST while performing internal circuit checks, and then it shows: READY. If any other display appears, turn the MBC in to the GS maintenance team. If the BATT (battery) LOW indicator flashes or the display does not appear, replace the battery or check the power connections.

(2) Perform the four self-test in any sequence. The SELF-TEST switch provides testing of the microprocessor (MICR), all switches and keys (SW), the display and indicators (DSP), and the modem (MOD).

(3) Press the TEST switch. If after pressing the TEST switch, the correct software revision number (Revision III/A) is not displayed, turn the MBC in to the GS maintenance team.

(1) Manual mode. When the MBC is not connected to an external communication device, all data are manually entered.

(2) Digital mode. When the MBC is connected to an external device (DMD-supported), data are digitally entered into the appropriate switch memory. Data entered digitally may be reviewed or supplemented manually.

(1) TEST and BRT. These keys are used first to check the overall MBC operation and to set the display brightness. The LOW setting in the BRT menu also lights up the keyboard for night or limited visibility usage.

(2) SET UP and WPN DATA. These two switches must be initialized. They are always manually entered in the MBC. Data will never change due to other switch action; however, the operator may review and update data as needed. When the AMMO DATA switch default values are suitable, this switch is not needed for initialization. The default values are:

• 60-mm mortar: HE, M720; WP, M302A1; and ILLUM, M83A3.
• 81-mm mortar: HE, M374; WP, M375; ILLUM, M301A3; TNG, M1; and RP, M819.
• 4.2-inch mortar: HE, M329A1; WP, M328A1; ILLUM, M335A2; and CS, XM630.
• 120-mm mortar: HE, M933, M934; WP, M929; ILLUM, M930.
• 120-mm (insert) mortar: HE, M374; WP, M375A2; ILLUM, M301A3.

(1) Press the ON/OFF switch. The display shows: POWERUP TEST momentarily, and then shows: READY. Use the test switch to manually start the MBC self-test. Perform the self-test as the situation permits or as advised by the supervisor.

(2) Use the BRT switch to select the level of display character brightness (LOW, MED, HI, and MAX). Use the LOW level to turn on the keyboard background lighting. Character brightness is always set at HI when the MBC is turned on or when the BRT switch is pressed.

(3) Press the SEQ switch. The display shows: READY. Press the SET UP switch. Use the multiple choice entry to change the time-out to the desired length. Use time-out to set the number of seconds (15, 30, 45, or 60); the display stays on between switch actions. The default value of 15 seconds provides for minimal battery drain. A time-out of 60 is recommended for the novice FDC computer.

(4) Press the SEQ switch. Using alpha entry, enter the target prefix AH.

(5) Press the SEQ switch. Using numeric entry, enter the target numbering block 0001 through 9999.

(6) Press the SEQ switch. Use the default shown: ALARM:OFF. Use message alarm for DMD-supported missions, if needed.

(7) Press the SEQ switch. Using numeric entry, enter the minimum easting coordinate 096.

(8) Press the SEQ switch. Using numeric entry, enter the minimum northing coordinate 029.

(9) Press the SEQ switch until OWN ID: _ is displayed. The E W GD:, + - LAT:, LISTEN ONLY: OFF, BIT RATE: 1200, KEYTONE: 1.4, and BLK:SNG information may be entered into the computer for expanded initialization.

(10) The final entry in the SET UP menu is the OWN ID. Enter the unit identification code located in the SOI.

(1) Press the WPN DATA switch. Use the multiple choice entry to select the desired section (A). With the weapon types displayed, select the caliber (107 mm).

(2) After the caliber of weapon is selected, the choice of carrier or ground-mount is next (except for the 60-mm mortar). The MBC defaults to CARRIER: NO. Ensure all weapons in the section are mounted the same. Using the multiple choice entry, select the CARRIER mode for the section. CARRIER: NO indicates the section is to be ground mounted. CARRIER: YES indicates the section is to be carrier mounted. The muzzle velocity is figured differently for ground mounted to carrier mounted. After entering the selection of carrier-mounted, press the SEQ switch and the display shows: CARRIER MV ENTERED. Carrier-mounted muzzle velocity corrections are entered into the memory of the MBC for that section.

(3) Press the SEQ switch. Enter the basepiece (BP) number using multiple choice entry (A2). The basepiece is just a reference for the MBC to locate the other mortars in that section. Time and effort are usually saved if one of the flank mortars is used as the basepiece.

(4) Press the SEQ switch. Enter the BP easting and northing grid coordinates. Most mortar locations are known to within eight-digit grid coordinates. To enter the coordinates, follow these instructions:

(1) Press the AMMO DATA switch. The display shows: 60 81 107 TEMP. Select the caliber of weapon being used (107 mm) by pressing the blue display switch (display switch No. 3) beneath the number 107.

(2) The display now shows: HE: M329A1 :NO. Flashing cursors are on the 2 and the N. These cursors indicate that changes may be made to the display. HE: M329A1 is the default value for the 107-mm mortar, so no changes are needed for the round type. However, the round also comes in different weights as explained earlier. Square weight is usually given on the exterior of the boxes that the ammunition comes in. The FT 4.2-H-2 has charts (pages X through XII) on the mean weights of all rounds and their fuze combinations, except for the M329A2. The weight of the M329A2 round is standard and requires no changes to weight or squares. Once the entry has been made either by weight in pounds or in squares, press the SEQ switch and the display shows: HE: M329A1 :CR.

(3) Press the SEQ switch. Continue the above procedures until all the ammunition requirements are entered.

(1) Always manually initialize MET for entry of nonstandard MET data. If the MET switch is not used, the MBC uses standard (STD) conditions for MET data. When the MET is entered, ensure that the SET UP menu has the current data for the grid declination (GD) and latitude (LAT).

(2) Always manually initialize and update FIRE ZONES when needed.

(3) Manually initialize and update FO LOC when in the manual mode. When the MBC is DMD-supported, input is automatically entered when a valid observer location message is received. This is also a good time to update the SET UP menu. The communication data are LISTEN ONLY: OFF, BIT RATE: 1200, KEYTONE: 1.4, and BLK:SNG.

(4) Initialize and update KNPT/TGT at any time regardless of the mode of operation. The KNPT/TGT switch may be updated automatically by the use of the EOM, REPLOT, and SURV switches, or by receiving digital messages related to the KNPT/TGT.

(5) Manually initialize REG DATA to maintain a registration file when enough data are known from conducting a fire mission. Normally registration data are generated automatically by using the REG switch during fire mission processing. However, data manually entered with the REG DATA switch are automatically updated when the REG switch is used to compute registration.