recorder/reproducer: (1) stop/edit, (2) fast wind/edit, and (3) play/edit. Selecting the stop/edit mode sets
only the edit brakes of the tape reel motors, thus facilitating manual cueing and threading of the tape.
Selecting the play/edit mode causes the tape to be pulled past the heads and spilled off the right side of
the transport. This mode is typically used when unwanted tape is to be cut off. The fast wind/edit mode
brings the tape into contact with the heads while the tape is being moved in the fast forward or rewind
modes, making the recorded portions audible for high-speed search.
c. Head assembly. Professional tape recorders employ three separate heads (fig 3-31). In their
order of head placement they are the erase head, the record head, and the reproduce head. The first to be
discussed will be the erase head.
(1) Previously recorded signals are erased from a magnetic tape by passing a high frequency
current through the erase head (fig 3-32). The tape passes over the erase head before it arrives at the
record head. To erase in the record mode, a high frequency signal supplied by the recorder's erase
oscillator, feeds current to the erase head. The current causes a strong alternating magnetic field to be
developed. This magnetic field returns a previously recorded tape to its original state before being
rerecorded.
Figure 3-32. Basic operation of recording or reproducing head
43
Previous Page
