Scully 280B Series User Manual

Model 280B
Main tenance
at other times deemed desirable by the user. In
multi-track machines, these procedures must be
repeated for each channel. The demagnetizing pro-
cedure described in paragraph 4.4 should be per-
formed prior to any checkout and alignment.
7.10 Test Equipment Required
The following test equipment, or equivalent, is
required to perform the checkout and alignment
procedures and for troubleshooting the machine:
• Standard alignment or test tape
• Audio Oscillator, Hewlett-Packard Model
204D
• AC Voltmeter, Hewlett-Packard Model 400F
• Flutter Meter, BHK Electronics Model F2
• Frequency Counter, Hewlett-Packard
Model 5245M
• Recording Tape, 3M 206
• Oscilloscope, Tektronix, Model 434 (20
MHz or better) with 10:1 probe
• Alignment tool, Scully Part No. 162235
(supplied with amplifiers)
•
400 Hz Filter, TRW Type No. BPM-400
• Volt-Ohm Milliammeter,
Simpson Model 260
• Weighting Filter, ASA "A" Curve Standard
S1.4-1961
7.11 Preliminary Procedures
To perform the following procedures, make the test
setup shown in Figure 7 -11 and proceed as follows:
A.
Thread a standard reproducer alignment tape
on the recorder .
B. Set controls as follows:
• CAPST AN speed
selector switch to HIGH
• Function switch to SAFE
• Monitor switch to PLAYBACK
• PLAYBACK LEVEL switch to CAL
C. Open the electronics drawer for access to cali-
bration adjustments (Figure 7-12).
,
t
400 H~
A
FILTER
l'
WEIGHTING
A
FILTER
SPEAKER
j~
AMPLIFIER
OR
HEADSET
OSCILLO-
AUDIO
SCOPE
OSCILLATOR
I
0
0
6
LINE OUT
LINE IN LINE OUT
LINE
IN
J 120 JII9
JII8
JII7
'------ CH 2
I
'------ C H
I~
ELECTRONICS
ASSY
Figure 7-11. Initial Test Setup
7.12 Playback Alignment
A. Begin tape motion by pressing START push-
button. Monitor the output on the external
ac voltmeter or recorder vu meter and speaker .
B.
Adjust the PLAYBACK LEVEL CAL potenti -
ometer (located in the center of the PLAY-
BACK
LEVEL knob) for 0 vu (+4 dBm) at
reference frequency and fluxivity on the re-
producer alignment tape.
C. Adjust the azimuth of the playback head for a
maximum signal output on the ACVM using
the right-hand slotted-head screw located on
top of the head bridge mounting plate (Figure
7-13).
7-10

Scully 280B Series Specifications

General

Brand	Scully
Model	280B Series
Category	Turntable
Language	English