JVC MXKB22
Service Manual

4.3

Cassette amp section

Item
Head azimuth adjustment

Measuring condition

Check and adjustment procedure

Standard value
Output level : Within (2 dB of Maximum output level. *Phase difference R and L channels : Minimum

Adjusting part
Head azimuth adjusting screw (To be use only after head replacement)

Test tape : VT703L 1. Playback the test tape VT703L. Signal output terminal : 2. Adjust the head azimuth adjusting screw so SPK out that the phase difference between the R and (with 6 ohm load) L channels is minimized at an output level that is within (20dB of the maximum output level. After this adjustment. Lock the head azimuth adjusting screw with screw sealant to cover more than a half of the screw head. 3. When the head azimuth is maladjusting correct it with the head azimuth adjusting screw.

Tape speed and Test tap : VT712 1. Playback the test tape VT712 by the end wow/flutter check Signal output terminal : portion. and adjustment SPK out 2. Connect a frequency counter and check that 2940 to 3090 Hz (with 6 ohm load) it reads between 2940 and 3090 Hz. If not, adjust the frequency with the motor semifixed resistor. 3. Check that the wow/flutter is within 0.35% within 0.35% (unweigthed). (unweighted) Bias frequency chek Test tape : B Signal output terminal : Cassette REC/Play head Set the Tuner or CD function and with TAPE to record check to see if the frequency at the measuring point REC-IF is 85 kHz if not adjust T100 until the frequency counter indicates 85 kHz+1kHz-1kHz. Level difference for 1 kHz signal : within (0+3dB-6dB)

Tape speed Motor semifixed resistor

Check only

Rec anf PB frequency response adjustment

Test tape : Brank tape Signal input : CD 1 kHz -20 dBs Signal output terminal : SPK out (with 6 ohm load)

Record the reference CD 1 kHz signal and 10 Level difference for kHz signal alternately repeatedly. While playing 1 kHz signal : back the recorded signal of the 1 kHz signal within (0+3dB-6dB) doffer from that of the 10 kHz signal by within (0+3dB-6dB).

4.4

Tuner section (B/EV version)

Item

Measuring condition
Loop antenna Signal output : IC602 pin 16

Check and adjustment procedure
1. Set the intermediate frequency sweep generator to AM 450 kHz. 2. Adjust IFT601 for maximum and center output 1. Set the TUNER at 522 kHz adjust IFT605 until the test point TP4 voltage at 1.3V+/-.1V. 2. Set the TUNER at 1629 kHz, check the test point TP4 voltage at 7.0 to 8.0 V. 3. Set the TUNER and S/G at 600 kHz, adjust ITT606 for maximum output. 4. Set the TUNER and S/G at 1500 kHz, adjust the VC606 for maximum output. 5. Repeat the avobe step 3 and 4.

Standard value

Adjusting part
IFT601

AM IF adjustment Signal input :

AM tracking adjustment

Signal input : Loop antenna signal output : H.phone out (with 32 ohm load)

IFT605

IFT606 VC606

FM tracking

Signal input : Analog antenna FM ANT Fm GND signal output : H.phone out (with 32 ohm load)

1. Set the TUNER at 87.5MHz adjust L604 until the point TP5 voltage at 1.5V+/-0.1V. 2. Set the TUNER at 108MHz, check the point TP5 voltage at 7.2-8.0V. 3. Set the TUNER and S/G at 90.1MHz, adjust L605 for amximum output. 4. Set the TUNER and S/G at 106.1MHz, adjust the VC604 for maximum output.

L604

L605 VC604

(No.MB306)1-29