9. REC C Current Adjustment (VC-214 board)
Set the recording current levels of the REC Chroma signal. If it is
too low, chroma signal noise in played back picture will increased.
If too high, Y signal noises will increase and white modulation noises
will be produced.
Mode
VTR recording (SP mode)
Signal
No signal
Pin 0 of CN910 (REC RF)
Measurement Point
Measuring Instrument
Oscilloscope
Adjustment Page
F
Adjustment Address
85
Specified Value
A=35.7 ± 1.3mV
Connection:
Remove C085 (0.01 µF, Pin !§ of IC202).
1)
Note: After completing "REC L Level Adjustment" and "REC C
Current Adjustment", replace C085 with new parts (1-162-970-
11 CERAMIC CHIP 0.01 µF 10% 25V).
Connect Pin $∞ of IC001 and GND with a 0.01F capacitor.
2)
0.01 µF capacitor: 1-101-004-00
Preparations only for the model without REC switch:
1)
Select page: 0, address: 01, and set data: 01.
2)
Select page: D, address: 14, after memorizing the data, set the
bit value of bit1 to "1". (Refer to "4-3, 3. Bit value
discrimination" of "5-4. Service Mode").
3)
Insert a tape, and set to recording mode. (Use the wireless
remote commander of 8mm VCR.)
Adjusting method:
1)
Insert a tape, and set to recording mode.
2)
Select page: 0, address: 01, and set data: 01.
3)
Select page: 2, address: 01, set data: 41, and press the PAUSE
button of the adjustment remote commander.
4)
Select page: 6, address: 61, and set data: 30.
5)
Select page: F, address: DE, after note down the data, set data:
00, and press the PAUSE button of the adjustment remote
commander.
6)
Select page: F, address: 85, change the data and set the REC
chroma signal level (A) to the specified value.
7)
Press the PAUSE button of the adjustment remote commander.
8)
Select page: F, address: DE, set the data noted down at step 5),
and press the PAUSE button of the adjustment remote
commander.
9)
Select page: 6, address: 61, and set data: 10.
10) Select page: 2, address: 01, set data: 00, and press the PAUSE
button of the adjustment remote commander.
11) Select page: 0, address: 01, and set data: 00.
Processing after completed adjustment only for the model
without REC switch:
1)
Select page: 0, address: 01, and set data: 01.
2)
Select page: D, address: 14, and set the data memorized at step
2) of "Preparations only for the model without REC switch".
3)
Press the PAUSE button of the adjustment remote commander.
4)
Select page: 0, address: 01, and set data: 00.
5-41
Center of the luminance line width
1.35 µ sec
Fig. 5-3-14.
A