Sec. 80.859  Main power supply.

    (a) The main power supply must simultaneously energize the 
radiotelephone transmitter at its required antenna power and the 
required receivers. Under this load condition the voltage of the main 
power supply at the radiotelephone input terminals must not deviate from 
its rated potential by more than 10 percent on ships completed on or 
after July 1, 1941, nor by more than 15 percent on ships completed 
before that date.
    (b) Means must be provided for charging any batteries used as a main 
power supply. A continuous indication of the rate and polarity of the 
charging current must be provided during charging of the batteries.