| 摘要 |
PURPOSE:To obtain a reproducing signal without no noise pulse at joints by providing two delay quantity variable type delay circuits retarding respectively FM signals reproduced by both heads so as to prevent a phase shift of an output signal of a loop changeover switch due to the joints. CONSTITUTION:The phase of an output signal of a voltage controlled oscillator 35 is controlled to the phase of a delay circuit under reproducing and tracing at present during the simultaneous reproducing trace period at head changeover, and the phase difference of output signals of both loop filters 32, 33 becomes the phase difference of the FM signal reproduced by both rotary reproducing heads based on the phase comparison between the output signal of the delay circuit to apply next reproduction tracing and the output signal of the voltage controlled oscillator 35, a capacitor 42 or 40 of the next rotary reproducing head is charged by a signal proportional to the phase difference so as to apply control that the delay quantity of the delay circuit of the next rotary reproduc ing head makes the phase of the output signal of the delay circuit coincident with the phase of the output signal of the delay circuit of the present rotary head. Thus, the phase of the output signal of both the loop filters 32, 33 is made coincident.
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