Measurements And Adjustments - Panasonic SA-DK10 Service Manual

SA-DK10

9 Measurements and Adjustments

9.1. Cassette Deck Section
• Measurement Condition
− Reverse-mode selector switch:
− Tape edit: NORMAL
− Record timer: OFF
− Make sure head, capstan and press roller are clean.
− Judgeable room temperature 20 ± 5 °C (68 ± 9°F)
• Measuring instrument
9.1.1. Head Azimuth Adjustment
Note :
If you wish to readjust the head azimuth, be sure to adjust with
adhering the casette tape closely to the mechanism by pushing
the cebter of cassette tape with your finger. (Shown in Fig. 1)
1. Connect the measuring instrument as shown in Fig. 2.
2. Replace azimuth screws for both forward and reverse
direction after removing the screw-locking bond left on the
head base.
3. Playback the azimuth adjustment portion(8kHz, -20dB) of
test tape(QZZCFM). Adjust the azimuth adjusting screw
until the outputs of the L/Rch are maximized. (Refer to Fig.
3)
Make sure that the difference in the peak level between the
left and right channels does not exceed 5dB.
4. Perform the same adjustment in reverse playback mode.
Check of the level difference forward and reverse
directions
5. Playback the playback gain adjustment portion(315Hz,
0dB) of test tape(QZZCFM). Check if level difference
between forward and reverse direction is within 1.5dB.
6. After the adjustment, apply screwlock to the azimuth
adjusting screw.
Fig. 1
Fig. 2
− EVM (Electronic Volmeter)
− Digital quency counter
• Test Tape
− Head azimuth adjustment (8 kHz, -20 dB); QZZCFM
− Tape speed gain adjustment (3 kHz, -10 dB);
QZZCWAT
− Playback gain adjustment (315 Hz, 0 dB); QZZCFM
− CrO2 tape, QZZCRX
9.1.2. Tape Speed Adjustment (Deck 1/2)
1. Set the tape edit button to "NORMAL" position.
2. Insert the test tape (QZZCWAT) to DECK and playback
(FWD side) the middle portion of it.
3. Adjust Motor VR for the output value shown below.
Adjustment target: 2940 ~ 3060 Hz (NORMAL speed)
4. After alignment, assure that the output frequency of the
DECK REV is within ±60 Hz respectively of the value of the
output frequency of DECK FWD.
9.1.3. Bias and Erase Voltage Check
1. Set the unit "AUX" position.
2. Insert the Normal blank tape (QZZCRA) into DECK and the
unit to "REC" mode (use "
3. Measure and make sure that the output is within the
standard value.
4. Insert the Cr02 tape(QZZCRX).
5. Repeat steps 2 and 3.
Bias voltage
Erase voltage for Deck 2
22
Fig. 3
REC/PAUSE" key).
16 ± 4mV (Normal)
26 ± 5mV (Cr02)
more than 80mV (Normal)
more than 90mV (Cr02)