Abstract: A retrofit unit for heating and cooling liquid stored in a recipient, the retrofit unit comprising: a housing defining a cavity and allowing the retrofit unit to be external to the recipient; a thermoelectric device in the cavity, comprising at least one thermoelectric module having a heat radiation side and a heat absorption side; a control unit in the cavity, for controlling the energy to be applied to the thermoelectric module; and a connecting element on the housing, the connecting element allowing the thermoelectric device one of direct contact and indirect contact with the liquid stored in the recipient to selectively heat and cool the liquid by emitting and absorbing heat, respectively.

Abstract: The present invention is a system and method for detecting a jamming signal. The signal is detected by analyzing a spectrum of PCS, wireless network and pager wavebands (or, in other words, any wireless network) and by looking for unusual patterns. If unusual patterns are found, it is considered that a jammer is present. In a preferred embodiment of the invention, the system can be aboard a recovery vehicle, or be an integral part of an on-board unit on a vehicle.