| 摘要 |
PURPOSE:To attain smooth reception of the normal control signal by setting two magnetic heads with such a distance that the mutual effects of signals in an audible frequency region and preventing a magnetic field leaked out of a magnetic head under a sound recording state from jumping into a magnetic head which is under a reproduction state. CONSTITUTION:At a time of sound recording, the signal supplied through a microphone 22 is supplied to an R-hannel magnetic head 31 via an R-channel preamplifier 12 which is working as a sound recording amplifier as well as a microphone amplifier 23. In this case, the bias supplied from a bias oscillator 24 is also superposed on the head 31. Then a modulated signal is recorded on a magnetic tape 8 through a gap of the head 31 in the form of a magnetic flux. In this case, the magnetic head gaps of L- and R-channels have a distance between them, and therefore the head 31 gives no effect to the magnetic head of the L channel. Thus the L-channel magnetic head can reproduce normally the control signal in the same way as a reproduction state. Therefore it is possible for a microprocessor 17 to perform normal reception via a signal detector 16. |
