Pioneer CT-L5, Service Manual

Page: 23 / 27

CT-L5
23
6.2 ADJUSTMENT
Please execute this adjustment in test mode 2.
7
Adjustment Condition
(1) The ground at the time of adjustment shall be W184.
(Refer to Fig. 6–4).
(2) Clean the heads and demagnetize them using a head eraser.
(3) Set the measurement level to 0 dBV = 1 Vrms.
(4) Use the specified tape for adjustment. Use the labeled (A) side
of the test tape.
NCT–111
: For Tape Speed adjustment
STD-331E : For Playback adjustment
STD–632 : Normal blank tape
* As the reference recording level is 250 nwb/m for STD–
331E, the recording level will be higher by 4 dB for STD–
331B (160nwb/m). When adjusting, pay carefull attention
to the type of tape used.
(5) Provide yourself with the following measuring devides:
÷
AC millivoltmeter
÷
Low-frequency oscillator
÷
Attenuator
÷
Oscilloscope
(6) Adjust both right and left channels unless otherwise specified.
(7) Turn the DOLBY NR switch off unless otherwize specified.
(8) Warm up the unit for several minutes before adjustment. In
particular, be sure to warm up the unit in the REC/PLAY mode
for 3 to 5 minutes before starting recording/playback frequency
characteristics adjustment.
(9) Always follow the indicated adjustment order.
Otherwise, a complete adjustment may not be achieved.
7
List of Adjustments
¶
Playback Section
(1) Tape Speed Confirmation
(2) Head Azimuth Adjustment
(3) Playback Level Adjustment
¶
Recording Section
(1) Recording Bias Adjustment
(2) Recording Level Adjustment
Note: In case of adjustment as a single unit, connect a 27 k
Ω
load
resistor to pins 17(PBR) and 19 (PBL)of CN2601(MAIN
UNIT ).
Dolby noise reduction manufactured under license from Dolby
Laboratories Licensing Corporation.
“DOLBY” and the double-D symbol are trademarks of Dolby
Laboratories Licensing Corporation.
0 dB
–20 dB
30s
0 dB: 315 Hz, 250 nwb/m
315 Hz
6.3 kHz 10 kHz 315 Hz 14 kHz
12.5
kHz
6.3
kHz
500
Hz
250
Hz
125
Hz
10 kHz 8 kHz 4 kHz 2 kHz
63 Hz 40 Hz
1 kHz
30 s 30 s 30 s 10s 10s .......................................................................................................... 10s
Fig. 6–3 Test Tape STD– 331E
Fig. 6–2 Frequency Characteristics
250
3dB
10k
12.5k
3dB
315Hz=0dB
315Hz=0dB
4dB
PLAY BACK
250
3dB
10k
12.5k
3dB 5dB
RECORDING
6.1.2 Test Mode 2
7
How to enter into Test Mode 2
(1) Press the “STOP” key in test mode 1 for at least 2 sec.
(2) When test mode 2 is entered, “TEST” is displayed on the CD
RECEIVER (XC-L5) displays the following, and the “PLAY”
and “REC” LEDs flash faster than in test mode 1.
7
Operation of test mode 2
(1) LINE MUTE opens in REC/REC PAUSE condition.
(2) When abnormal operation is detected, the corresponding code
will be displayed on the CD RECEIVER (XC-L5) display.
Otherwise, operation and display are the same as in normal
condition.
7
Cancellation of test mode 2
Press the “STANDBY/ON” key or disconnect the AC power
supply.