Panasonic AJ-D455P, Service Manual

Page: 66 / 743

ELE-9
3-6. REC Frequency Characteristic
and REC Current Adjustment
(DVCPRO 25M)
BOARD EQ MAIN (H2)
TP TP6, TP2 (Trigger)
Audiometer (Error Rate Display)
ADJ. Service Menu
TAPE 525(NTSC): VFM3580KM (L)
Alignment Tape (Color Bar)
DVCPRO Recording tape
INPUT
Color bar
MODE
PLAY
M. EQ Spectrum analyzer
SPEC. -----
1. Set a spectrum analyzer as follows.
Parameter 25M Mode
REF LEVEL -----
ATTEN 10dB
/DIV 2dB
START FREQ 0MHz
STOP FREQ 40MHz
RES BW 1MHz
VBW 1KHz
SWEEP TIME 150ms
V AVG OFF
TRIG EXT
2. Extend the RF/EQ (F8) Board. Connect the
spectrum analyzer INPUT to TP6 and the external
trigger to TP2.
3. Insert the recording tape and record the color bar
signal.
4. Open the Service Menu.
5. Open the B00: RF ADJUST.
6. Open the C00: PRO ADJUST.
7. Open the C-1: REC ADJUST.
8. Set the numerical value of C01: REC CURR L
and C03: REC CURR R as follows.
C01: REC CURR L
à
à à
à
+120
C03: REC CURR R
à à à à
-120
9. Read (memorize) the spectrum at the confidence
playback into the TRACE B, and continue to
observe it with the TRACE A.
10. Adjust the C01: REC CURR L so that the level
difference between the TRACE B (The spectrum
memorized at the confidence playback) and
TRACE A (The real time spectrum at the
confidence playback) at 5MHz portion is in the
following specification.
TRACE B – TRACE A : 1dB +1dB/-0dB.
(After adjustment, memorize the adjustment value
of the C01: REC CURR L.)
11. Adjust the C02: REC FREQ L so that the level
difference between the TRACE B (The spectrum
memorized at the confidence playback) and
TRACE A (The real time spectrum at the
confidence playback) at 20MHz portion is in the
following specification.
TRACE B – TRACE A : 0dB +/-1dB.
12. Set the numerical value of C01: REC CURR L
and C03: REC CURR R as follows.
C01: REC CURR L
à à à à
-120
C03: REC CURR R
à
à à
à
+120
13. Read (memorize) the spectrum at the confidence
playback into the TRACE B, and continue to
observe it with the TRACE A.
14. Adjust the C03: REC CURR R so that the level
difference between the TRACE B (The spectrum
memorized at the confidence playback) and
TRACE A (The real time spectrum at the
confidence playback) at 5MHz portion is in the
following specification.
TRACE B – TRACE A : 1dB +1dB/-0dB.
(After adjustment, memorize the adjustment
value of the C03: REC CURR R.)
15. Adjust the C04: REC FREQ R so that the level
difference between the TRACE B (The spectrum
memorized at the confidence playback) and
TRACE A (The real time spectrum at the
confidence playback) at 20MHz portion is in the
following specification.
TRACE B – TRACE A : 0dB +/-1dB.
16. For the C01: REC CURR L value and the C03:
REC CURR R value that have been pre-adjusted
in the steps 10 and 14, add +50 to them
respectively for readjustment (fine adjustment).
17. Insert the recording tape and record the color bar
signal approximately one minute and play it back.
18. Check that the error rate is less than “A” level of
the figure. (When confirm the error rate, select
C44: ERROR MODE and change the setting from
“FAST” to “SLOW”.)
Read (memorize) the playback spectrum into the
TRACE B.
19. Insert the DVCPRO alignment tape (VFM3580KM
(L)) and play it back.
20. Confirm that the level difference between the
TRACE B (Memorized self-recording playback
spectrum) and TRACE A (Alignment tape
playback spectrum) at 5 MHz is in the following
specification.
TRACE B – TRACE A : 0 dB +/- 2dB.
dB
Error Rate
L
CH 2
CH 1
R
A
For changing the VIDEO/AUDIO error rate
display, press the “DIAG” button.
CH1 Light Up : Audio Error Rate Display
CH2 Light Up : Video Error Rate Display
Channel Condition LED is not working when
open the RF ADJUST menu in the service menu.
(The all three LED (Red, Blue, Green) turns on.)