5-57
Pattern generator
VTR
Audio level meter
or distortion meter
600
Ω
47 k
Ω
Attenuator
Input to both L and R
channels simultaneously
VIDEO OUT
VIDEO INPUT
AUDIO OUTPUT
AUDIO INPUT
600
Ω
: 270 (1-249-410-11) +330 (1-249-411-11)
47 k
Ω
: 1-249-437-11
Audio
generator
Fig. 5-3-20
3-5. AUDIO SYSTEM ADJUSTMENTS
Connection of Equipment
1.
Playing Level Check
Mode
PLAY
Signal
Alignment tape: For audio check
(NTSC: XH5-3/PAL: XH5-3P)
Measurement Point
AUDIO OUTPUT terminal (L and R)
Measuring Instrument
Audio level meter, Oscilloscope
Specified Value
32 kHz mode section:
1 kHz signal must be outputted.
48 kHz mode section:
1 kHz signal level is +4 to +8 dBV.
44.1 kHz mode EMP ON section:
7.35 kHz signal level is –5 to –7 dB
for 1 kHz signal level in 48 kHz
mode.
44.1 kHz mode EMP OFF section:
7.35 kHz signal level is –1 to +1 dB
for 1 kHz signal level in 48 kHz
mode.
Note:
0 dBV = 1 Vrms
Checking method
1) Check that the play signal level satisfies the specified value.
2) Check with the oscilloscope that no clip is found in the output
waveform.
2.
E-E S/N Check
Mode
E-E
Signal
Audio: 1 kHz, +4 dBV signal
no signal
AUDIO INPUT terminal (L and R)
Video: Color bar
VIDEO INPUT terminal
Measurement Point
AUDIO OUTPUT terminal (L and R)
Measuring Instrument
Audio level meter
Audio noise meter
(with A-weight filter)
Specified Value
92 dB or more
Switch setting
INPUT SELECT switch........................VIDEO (except DV)
Menu setting (AUDIO SET menu)
AUDIO MODE.................................................FS48K
Checking method
1) Enter 1 kHz, +4 dBV signal to the AUDIO INPUT terminals
(L and R).
2) Measure the output level of the AUDIO OUTPUT terminals
(L and R), and assume them to be S
L
(dBV) and S
R
(dBV)
respectively.
3) Place the AUDIO INPUT terminals (L and R) in the no-signal
state.
4) Measure the noise level (A-weight filter ON) of the AUDIO
OUTPUT terminals (L and R), and assume them to be N
L
(dBV)
and N
R
(dBV) respectively.
5) Obtain a difference (dB) between S
L
(dBV) and N
L
(dBV) to
check that it satisfies the specified value.
S
L
(dBV) – N
L
(dBV) 92 (dB)
6) Obtain a difference (dB) between S
R
(dBV) and N
R
(dBV) to
check that it satisfies the specified value.
S
R
(dBV) – N
R
(dBV) 92 (dB)