Guide Roller Height Adjustment; Preliminaryadjustment; 4-2. Precise Adjustment - Aiwa D33 Service Manual

DECK MECHANISM ADJUSTMENT
4.Guide Roller Height Adjustment
Purpose: To regulate the Height of the Tape so that the Bottom of the Tape runs along the
Tape Guide Une on the Lower Drum.
4-1. Preliminary Adjustment
Test Equipment/Fixture
• Post HetghtAdjustmg Dnver
Test Conditions (Mechanism Condition) I
• Play or Revrew Mode
Adjustment Point
• Guide Roller Height Adlustment
screws on the Supply and Take-Up
Gutde Rollers
Adjustment Procedure
1) Confirm d the Tape runs along the Tape Guide Line of the
Lower Drum
2) If the Tape runsthe Bottomof the Gu_e Line. rum the Guide
RollerHeightAdJustment S crewto Clockwisedfrec_on
3) If it runsthe Top, turnto Counterclockwise directon
4) Adjustthe Heightof the Guide Rollerto be gutded to theGuide
Lineof the Lower Drum fTomthe Startingand EndingPointof
the Drum.
ADJUSTMENT DIAGRAM
_Guide Holler Height
, _ jttju_tm_t screw
I Upper Flange
_i _ q--Guide Roller
._ Retaining Screw
Fig. C-4-1
4-2. Precise Adjustment
Test Equipment/Fixture Test Equipment Connection Points
• Oscdloscope
• Ahgnment Tape
• Post Height Adiustmg
Dnver
• CH-1 PB RF Envelope
• CH-2 NTSC SW 30Hz
PAL SW 25Hz
• Head Switching Output
Pomt
• RF Envelope Output
Point
Test C onditions VCR(VCP) State
• Playan Ahgnment T ape
Waveform Diagrams
P2 POST
ADJUSTMENT
Adjustment Point
•Gutde Roller Hetght
Adjustment Screws
Adjustment Procedure
1) Play an Alignment Tape after connectingthe Probe of the
Oscilloscope to the RF Envelope Output Test Pornt and
Head SwttchmgOutput Test PomL
2) Trscktng Control(m PB Mode) . Center Posttton(When
thts Adjustment msperformed after the Drum Assembly
has been replaced, set the Tracking Control so that the
RF Output is Maximum).
3) Hetght Ad}ustrnent Screw Ratlen the RF Waveton'n
(Fig C-4-2)
4) Turn(Move) the Tracking Control(m PB Mode)
ADJUSTMENT to f_dtenthe waveform.
Fig. C-4-2
Clockwise and Counterclockwise (Fig C-4-3)
5) Check that any Drop of RF Output ,s uniformat the
Start and End of the Waveform
NOTE
If the adjustment ,s excessive or insufficient the tape
wtll lam or told
- lLIU]lHIIlllll!lll/llillllllIHlI
Turn(Move)the tracking
Trackingcontrol at center control to both directtons
Fig. C-4-3
Connection Diagram
OSC,LLOSCOPE
RF ENVELOPEOUTPUTTEST POINT --
HEAD SWITCHINGOUTPUTTEST
POINT
19