Input Level Switching Check; Microphone Power Supply Check - Sony DSR-50P Service Manual

9. Input Level Switching Check

Switch setting
DISPLAY (LCD OFF/OFF/ON) switch ...................... ON
DISPLAY (MENU/TC/AUDIO) switch ...................... AUDIO
REC LEVEL CONTROL SELECT switch (CH-1 to CH-4) ..... AUTO
VIDEO INPUT SELECT switch .................. VIDEO (except DV)
AUDIO INPUT SELECT switch (CH-1 to CH-4) .............. LINE
Menu setting (AUDIO SET menu)
AUDIO MODE ...................... FS32K
REF LEVEL ........................... –20
LIMITER ................................ OFF
(1) –20 dB check
Mode STOP
Signal Audio: 1 kHz, –22 dBu (to –18 dBu)
signal
AUDIO INPUT terminal (CH-1 to 4)
Measurement point AUDIO INPUT terminal (CH-1 to 4)
Measuring instrument Audio level meter
Specified value –22.0 dBu to –18.0 dBu
Checking method
1) Set the input level adjusting switch (CH-1) on the right panel
to "–20".
2) Enter 1 kHz, –22 dBu signal to the AUDIO INPUT terminal
(CH-1).
3) Press the "FINE" button on the front panel to display the audio
level indication of the LCD monitor on the FINE screen.
4) Raise the output of balance audio oscillator to "–22.0 dBu"
t "–21.9 dBu" t "–21.8 dBu" ... until the level indication
on the FINE screen on the CH-1 becomes "–20.0 dBu".
5) At this time, measure the AUDIO INPUT terminal level on the
CH-1 to check that it satisfies the specific value.
6) For the CH-2, 3 and 4, perform checking in the same manner.
(2) –60 dB check
Mode STOP
Signal Audio: 1 kHz, –60 dBu signal
AUDIO INPUT terminal (CH-1 to 4)
Measurement point AUDIO OUTPUT terminal (CH-1 to 4)
Measuring instrument Audio level meter
Specified value –14.0 dBV to –10.0 dBV
Checking method
1) Set the input level adjusting switch (CH-1) on the right panel
to "–60".
2) Enter 1 kHz, –60 dBu signal to the AUDIO INPUT terminal
(CH-1).
3) At this time, measure the AUDIO OUTPUT terminal level on
the CH-1 to check that it satisfies the specific value.
4) For the CH-2, 3 and 4, perform checking in the same manner.
(3) +4 dB check
Mode
Signal
Measurement point
Measuring instrument
Specified value
Checking method
1) Set the input level adjusting switch (CH-1) on the right panel
to "+4".
2) Enter 1 kHz, +4 dBu signal to the AUDIO INPUT terminal
(CH-1).
3) At this time, measure the AUDIO OUTPUT terminal level on
the CH-1 to check that it satisfies the specific value.
4) For the CH-2, 3 and 4, perform checking in the same manner.

10. Microphone Power Supply Check

Mode
Signal
Measurement point
Measuring instrument
Specified value
Note 1: Connect to the chassis of the set (such as GND of VIDEO/
REF.IN terminal).
Switch setting
AUDIO INPUT LEVEL CONTROL switch (CH-1 to CH-4)
........................................................................ –60
Checking method:
1) Connect the + probe of digital voltmeter to the pin 2 on CH-
1.
2) Set the audio input select switch (CH-1) on the right panel to
"+48V ON".
3) At this time, check that the DC voltage (A) satisfies the
specified value.
4) Check that the DC voltage (B) satisfies the specified value
when the audio input select switch (CH-1) on the right panel
is set to "LINE" and "CAM".
Note 2: In the "LINE" position, the discharge time of +48V is
long, and therefore set the switch to "CAM" first to
discharge +48V rapidly.
5) Connect the + probe of digital voltmeter to the pin 3 on CH-
1, and repeat steps 2) to 4).
6) For the CH-2, 3 and 4, perform checking in the same manner.
5-95
STOP
Audio: 1 kHz, +4 dBu signal
AUDIO INPUT terminal (CH-1 to 4)
AUDIO OUTPUT terminal (CH-1 to 4)
Audio level meter
–15.0 dBV to –9.0 dBV
STOP
No signal
AUDIO INPUT terminal (CH-1 to 4)
+ probe: pin 2, 3
– probe: GND (Note 1)
Digital voltmeter
Audio input select switch
In +48V ON position:
A = +45 V to +50 V
In CAM or LINE position:
B = 0 V to +1 V