Grundig RRCD 3700 MP3, Service Document

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RRCD 3700 MP3
1 ) Check source voltage, DC or AC according to specifications . 2 ) Set function switch to Tape being aligned .
A ) MEASURING INSTRUMENTS REQUIRED FOR TAPE B ) EQUIPMENTS REQUESTED FOR AC BIAS FREQUENCY / CURRENT ADJUSTMENT :
SPEED AND HEAD AZIMUTH ADJUSTMENT.
( 1 ) TAPE SPEED ADJUST
MTT-211NA (3150 Hz) TEST
AC BIAS FREQUENCY ALIGNMENT :
Note :The test unit should be keep in recording mode and added two resistors Ra & Rb as shown in the
Fig. 2 before alignment. be sure to delete the both resistors Ra & Rb after alignment completed.
t n i o P t s e T . T N E M T S U J D A H T U M I Z A D A E H ) 2 ( Adjust Frequency Frequency Observe at Observe
2.1 - Connect the equipments as shown in the Fig. 1. at Beat 0 Beat 1 Beat 2 Beat 0 Beat 1 Beat 2
(The Both Speakers loading Are Required) Resistor
2.2 - Insert a test tape ( 10 KHz : MTT-114 ) into deck.
Ra or Rb L401 60 KHz ± 0.3K
2.3 - Press PLAY and set VOLUME at reference output.
2.4 - Adjust the azimuth adjustment screw for the max.
& balance ch. output on both ch. of oscilloscope.
2.5 - Secure above screw with glue after adj. completed.
GENERAL PREPARATION -
==> TO CASS PCB
CN401
62KHz
1
Ra
10 ohm
Rb
10 ohm
4
INPUT
OUTPUT
VTVM
FREQUENCY
COUNTER
FIG.2
MOTOR
SPEAKER
TERMINALS
AZIMUTH ADJ. SCREW
TAPE IS REQUIRED
R/P HEAD
OSCILLOSCOPE
CH. 2
3150 Hz
CH. 1
FREQUENCY
COUNTER
FIG.1
R/P HEAD