FMU-140/B DISPENSER PROXIMITY FUZE

alternate method used to provide operation when the fuze is not initiated with the +300 volts dc. The conventional mode is selected by initiating the fuze with +300 volts dc. When the fuze is initiated with +300 volts dc, the Mk 43 operates automatically. The fuze circuitry produces a lobe pattern. It radiates a pattern at right angles (fig. 1-12) to the longitudinal axis of the weapon. When the Mk 43 is initiated by the conventional method, fuze functioning occurs instantaneously when a firing pulse is received from the thermal battery. If the alternate method is used (striker rod), the fuze is set for either of the two functioning delays. Detonation of the bomb is delayed by either 0.015 second or 0.100 second, depending on the delay that is selected. FMU-140/B DISPENSER PROXIMITY FUZE The FMU-140/B (fig. 1-13) has an optional arm and fire (timer) mode. It is used with the Rockeye II and Gator weapons. The FMU-140/B is a self-powered doppler radar device acting as a radar altimeter. Arming times and functioning altitudes are variable and are preflight selectable on the fuze faceplate, located on the side of the fuze. In the proximity mode, if the preselected altitude is reached before the fuze has had time to arm, or the dispenser is released below the pre-selected altitude, the fuze will have the potential to function anytime after arming. If the fuze has not functioned by the time it reaches an altitude of 300 ±25 feet, it will function at that time. REVIEW NUMBER 4 Q1. All electric capability for Mk 80 with either conical or retarding fins, thermally protected bombs, and laser-guided bombs is provided by _____________________. Q2. No unusual RADHAZ precautions are taken when using the Mk 376 fuze because it is classified as _____. 1-16 Figure 1-12.—Mk 43 Mod 0 target detecting device antenna pattern. Figure 1-13.—FMU-140/B dispenser proximity fuze.