JVC RC-W305, Service Manual

RC-W305

7

    e.   FM Adjustment

Band switch : FM

             FM Dummy antenna : 75 ohms unbalance

 Adjusting                            Connection

position of

VTVM

 Circuit

Input

Output

tuning dial

Oscilloscope

  Connect sweep

1

IF

generator  to  IC101

10.7 MHz

Low

T101

~

T103

(18)PIN(A) 

2

Tuning 

Connect FM SG to

Connect VTVM to

 87.4 MHz

Low end 

L103

3

coverage

FM ANT & D105(-)

speaker terminals.

108.4 MHz

High end 

PVC101-C1

4

Connect FM SG to

Connect VTVM to

90.0 MHz

90.0 MHz 

L102

5

FM ANT &D105(-)

speaker terminals.

106.0 MHz

106.0 MHz

PVC101-C2

偩

.TAPE DECK ADJUSTMENTS

    1. HEAD REPLACEMENT

        After replacement, demagnetize. the heads by using a degausser. 
        Be sure to clean the head before attempting to make any adjustments.
        All wiring should be returned to the original position after work is completed.
 

    2. HEAD AZIMUTH ADJUSTMENT

    (1) Load the test tape(VTT-703, etc., 10 KHZ) for azimuth
         adjustment. 
    (2) Press the PLAY button.
    (3) Use a cross-tip screwdriver to turn the screw for azimuth
         adjustment so that the left and right output are maximized
    (4) Press the STOP button.
    (5) After completion of the adjustment, use thread lock(TB-1401B)
         to secure the azimuth-adjustment screw.

   3. MOTOR SPEED ADJUSTMENT

   (1) Insert the test tape(MTT-111N, etc., 3,000 HZ)
   (2) Press the PLAY button.
   (3) Use a flat-tip screwdriver to turn the SVR(located inside the 
        rear of the motor) to adjust SVR so that the frequency counter
        become 3,000 HZ

   4. CHECKING THE MECHANISM TORQUSE AND TENSION

       Clean the head, capstan and pinch roller making any measurement.

Measurement

Take-up torqe

              Back  tension

Tape  tension

           Drive-power cassette

Cassette ofr                        PLAY:TW-211A

         PLAY: TW-2111A

measurement                     F.FWD/REW:TW-2231

   TW-2412

PLAY

                         30-60 gr.cm

             2.0 - 4.5 gr. cm

60 gr or more

F.FWD

                         55-120 gr.cm

 ------

    ------

REW

                         55-120 gr.cm

 ------

    ------

Step

SG Frequency

Tracking

Max.

Max.

Adjustment

 Connect sweep
generator to
 IC101(24)pin (B)