The invention provides for the reception of a L-band signals and MF-band signals using a single antenna element by employing an L-band antenna in conjunction with a connection cable that acts to receive MF-band signals, the invention further providing for the isolation of the L-band signals from an MF-band processing path and isolating the MF-band signals from an L-band processing path. A first controller is provided for operating the first set of memory devices in a working mode and the second set of memory devices in a standby mode, copying data from the memory devices of the working mode into a main memory and further into the memory devices of the standby mode, and performing a switchover between the operating modes when trouble occurs in the first set of memory devices. The pot desirably is divided into an upper portion and lower portion, wherein the liquid circulates from the lower portion to the upper portion and from the upper portion to the lower portion during heating.