Measurements And Adjustments; Cassette Deck Section; Tuner Section - Panasonic SA-AK230GCP Service Manual

SA-AK23 0GCP

14 Measurements and Adjustments

14.1. Cassette Deck Section

· Measurement Condition
− − − − Make sure head, capstan and press roller are clean.
− − − − Judgeable room temperature 20 ± 5 °C (68 ± 9°F)
· Measuring instrument
− − − − EVM (DC Electronic voltmeter)
− − − − Digital frequency counter
· Test Tape
− − − − Tape speed gain adjustment
QZZCWAT
14.1.1. Tape Speed Adjustment (Deck 1/2)
1. Set the tape edit button to "NORMAL" position.
2. Insert the test tape (QZZCWAT) to DECK 2 and playback
(FWD side) the middle portion of it.
3. Adjust Motor VR (DECK 2) for the output value shown
below.
Adjustment target: 2940 ~ 3060 Hz (NORMAL speed)
4. After alignment, assure that the output frequency of the
DECK 1 FWD are within ±60 Hz of the value of the output
frequency of DECK 2 FWD.
14.1.2. Bias and Erase Voltage Check
1. Set the unit "AUX" position.
2. Insert the Normal blank tape (QZZCRA) into DECK 2 and
the unit to "REC" mode (use "l REC/STOP" key).
3. Measure and make sure that the output is within the

14.2. Tuner Section

14.2.1. AM-IF Alignment
1. Connect the instrument as shown in Fig.5.
2. Set the unit to AM mode.
3. Apply signal as shown in Fig. 5 from AM-SG.
4. Adjust Z2602 so that the output frequency is maximized in
Fig. 6.
(3 kHz, -10 dB);
Fig.1
standard value.
Bias voltage for Deck 2
Erase voltage for Deck 2
14.1.3. Bias Frequency Adjustment (Deck
1/2)
1. Set the unit to "AUX" position.
2. Insert the Normal blank tape (QZZCRA) into DECK 2 and
set the unit to "REC" mode (l use "REC/STOP" key).
3. Adjust L1002 so that the output frequency is within the
standard value.
Standard Value: 97 ±8 kHz
48
14±4mV (Normal)
80mV (Normal)
Fig.2
Fig.3
Fig.4
Fig.5