29
VC-V50S
VC-V80T
VC-V91T
CHECKING OF PLAYBACK LEVEL
Measuring
instrument
Mode
Oscilloscope
Record/Playback
AUDIO CIRCUIT ADJUSTMENT
CHECKING OF E-E LEVEL
1. Connect an AC milli-voltmeter to the AUDIO OUT jack.
2. Playback the Alignment tape. (VROCPSV 1kHz level
audio signal)
3. Make sure that the output level is value shown in table.
CHECKING OF AUDIO RECORD LEVEL
Measuring
instrument
Mode
Input signal
AC milli-voltmeter
Playback
Alignment tape.(VROCPSV) (1kHz
level control signal.)
Test point
AUDIO OUT jack
Specification
–12
±
3 dBs
Cassette
Self-recorded tape (PAL)
(See Note below
1
)
Measuring
instrument
Mode
Input signal
AC milli-voltmeter
E-E/Record
1kHz, –8.0 dBs (at RCA type jack)
Test point
AUDIO OUT jack
Specification
–8.0
±
3 dBs
1. Connect an AC milli-voltmeter to the AUDIO OUT jack.
2. Feed the audio signal shown in table to the AUDIO IN
jack.
3. Put the unit in E-E or recording mode.
4. Make sure that the output level is value shown in table.
CHECKING OF AUDIO PLAYBACK LEVEL
Specification
1.0
±
0.2 Vp-p
1. Be sure that E-E level has been correctly specificed.
2. Connect a 75 ohm terminating resistor to the VIDEO OUT
jack and connect an oscilloscope across this terminating
resistor.(See Note below
1
)
3. Play an Alighment tape or a self-recorded tape.
4. Make sure that the output signal amplitude is
1.0Vp-p as shown in Figure 5-4.
Note:
1
If the 75 ohm terminating resistor is missing, the signal
amplitude will be doubled.
2
Self-recorded tape is a tape which program was re-
corded by the unit being adjusted.
Figure 5-4.
1.0 Vp-p
Measuring
instrument
Mode
Input signal
AC milli-voltmeter
Record/playback
1kHz, –8.0 dBs
Test point
AUDIO OUT jack
Specification
–8.0
±
3 dBs
Measuring
instrument
Mode
Test point
Oscilloscope
Record
Full erase head
Control
T601
Specification
70
±
5kHz, 40Vp-p or greater
1. Connect an oscilloscope across the full erase head.
2. Put the unit in recording mode.
3. Make sure the erase voltage across the full erase head
is approx. 40Vp-p or more and frequency is 70
±
5kHz.
1. Connect an AC milli-voltmeter to the AUDIO OUT jack.
2. Feed the audio signal shown in table to the AUDIO IN
jack.
3. Make the self-recording and playback of the signal.
4. Make sure that the output level is value shown in table.
CHECKING OF ERASE VOLTAGE AND OSCIL-
LATION FREQUENCY