A protection device for monitoring current in a power cable to an electrical device and for controlling a remotely located starter for the electrical device in response to a system controller. Thereafter, the highest voltage is produced and applied to the battery to charge the same. The transmitter transmits the spread signal across a communication link that introduces burst noise. The bias current output from the emitter of the transistor Q13 is supplied to the amplification circuit 60 via an attenuation filter F1. A pair of gates generates a corresponding pair of duty cycle adjusted versions of the input signal. Reinforcing means comprising an internal support framework supports the spa against the lateral external forces generated as a result of in-ground installation.