NOTE: The stylus should be at approximately an angle of 45, when mounted on
i. Check for correct speed control using a strobe disc.
j. Check input and output connectors.
Learning Event 2:
IDENTIFY THE PARTS OF AUDIOTAPE RECORDER/REPRODUCERS
Audiotape recorders/reproducers as they apply to an audio or TV production are discussed here.
The discussion is in three main sections: transport mechanism, head assembly, and electronics. There
are variations in the functions of each of these main sections.
a. Transport mechanism. All of the tape machines require some type of mechanism to move the
tape past the record and playback heads. Such mechanisms have been given various names, but "tape
transport" is generally accepted as standard.
(1) Features of the tape transport (fig 3-31) include the tape supply reel, which has either a
friction brake or an active back-torque. The back-torque is supplied by the drive system or a torque
motor. Back tension (torque) keeps the tape from becoming tangled due to the inertia of the tape reel.
The tension idler holds a certain amount of tape in its loop; this spare tape is temporarily let out during
quick starts. A slight delay is allowed for the supply reel, which has appreciable inertia, to start turning
at operating speed. The tension idler and back-torque work together to smooth out irregularities caused
by the rubbing of the tape against the supply reel sides, sticking together of tape layers, or other causes.
(2) The tape is drawn from the tension idler, across the rolling tape guide, erase head, tape
guide, record head, tape guide, and reproduce head. The force which draws the tape across the heads at
a constant speed is provided by the capstan and the capstan pressure roller. The combination of the
capstan, the tension idler, and the reverse torque of the supply reel keeps the tape under constant tension.
There is friction between the tape and the stationary heads. This friction is a source of vibration. To
help eliminate this vibration the transport mechanism components are mounted on a rigid base. Other
causes of vibration are: the amount of wrap around the head, smoothness of head faces, tape tensions,
tape condition, tape composition, temperature, and humidity. The capstan may be either the shaft of the
drive motor or a shaft driven through a speed-reducing mechanism. The capstan drive motor, and any
associated mechanism must be made with precision, and drive the tape at a constant speed, or they will
cause problems during both record and playback.
(3) Immediately following the capstan and the capstan pressure roller is another tape guide to
keep the tape in alignment with the heads. If the tape guides permit any vertical variation of the tape,
the recorded signal may be attenuated during reproduction. In extreme cases the signal can be