Scully 280B Series User Manual

Addendum I, Model 280B
Constant Tension Feature
1.3 Constant Tension Adjustment
High voltage is present
tension sensor PWA.
on the
a. Open the screw valve
not noticeable.
on the airpot until the damping effect is
b. Connect a Simpson Model 270 or equivalent VOM, set to the
250 Vac scale, across the supply motor terminals (JI06 pin
and NE UTRAL.
3
c. Loosen the locknut on resistor R204 on the power supply. Turn
R204 for a minimum resistance (fully ccw). Hold a piece of
black paper in the slot of the opto coupler. Put the machine
In Play mode and observe the VOM.
85 ±5 volts rms.
It should indicate
d.
Turn R204
voltage.
cw until the voltage drops 3 volts
Tighten the lock nut on R204.
rms. Record this
e. Check that the optical grating is rotating In the
opto coupler slot as shown in Figure 2a and 2b.
center of the
f. Loosen the setscrew on thE:: coupler, Figure 2a, and move the
dancer arm to the fully ccw (from the top) position. Position
the optical grating for minimum voltage reading across the
motor. The VOM should indicate 8 ±3 volts rms.
g. Move the dancer arm to the 7:00 o'clock position (from the
top). The voltage should be the same as recorded in step d.
2

Scully 280B Series Specifications

General

Brand	Scully
Model	280B Series
Category	Turntable
Language	English