3M DELTA Series - Page 25

H. HEAD HEIGHT AND ZENITH ADJUSTMENT
The magnetic tape head nearest the capstan
shaft is the reproducing head. The head farthest
from the capstan is the recording head except on
playback only machines. A dummy head is mounted
in this position on playback machines in order to
maintain constant tension on the tape and thus min 
imize wow and flutter and improve tape guidance.
The adjustment procedure outlined below should
be followed in positioning both the reproducing and
recording heads. Only height and zenith adjustments
are required for a "dummy" head. See Figure 3-12
for the location of the adjustment screws.
1. Loosen the lock nut by turning it counterclock 
wise approximately two complete turns.
2. Coarse Height: Adjust the Front Height Set Screw
until the top of the upper head track (pole piece)
is 9/16 of an inch (14.29 mm) above the deck
surface.
3. Coarse Zenith: Adjust the Rear Height Set Screw
until the face of the head is perpendicular with
the surface of the deck. Position the Tape Height
Gauge, or any gauge known to be square, on
the deck surface and move it against the face of
the head as shown in Figure 3-14. The gauge
must be demagnetized before making adjust
3-6
Figure 3-15