Zenith XBV243 series Service Manual page 53

CONFIRM OPERATION
Confirm that the Tape passes smoothly between the
Take-up Guide and Pinch Roller (using a Mirror or the
naked eye).
1) After completing Step 5-1. (Preliminary Adjust-
ment), check that the Tape passes around the Take-
up Guide and Pinch Roller without Folding or Curl-
ing at the Top or Bottom.
2) If Folding or Curling is observed at the Bottom of
the Take-up Guide, slowly turn the Tilt Adjustment
Screw (C) Clockwise.
PRECISE ADJUSTMENT
(Azimuth adjustment)
Test Equipment/ Fixture
Oscilloscope
Alignment Tape(SP)
Screw Driver(+) Type 5mm
Adjustment Procedure
1) Connect the Probe of the Oscilloscope to Audio Output
Jack.
2) Alternately adjust the Azimuth Adjustment Screw (A)
the Tilt Adjustment Screw (C) for Maximum Output of the
1Khz and 7Khz segments, while maintaining the flattest
Envelope differential between the two Frequencies.
X-VALUE ADJUSTMENT
Purpose: To obtain compatibility with other VCR (VCP) Models.
Test Equipment/ Fixture
Oscilloscope
Alignment Tape (SP only)
Screw
Adjustment Procedure
1 ) Release the Automatic Tracking to run long enough for
Tracking to complete its Cycle.
2 ) Loosen the Fixed Mounting Screw and move the Base
Assembly A/C Head in the direction as shown in the
Diagram to find the center of the peak that allows for the
maximum Waveform Envelope.
This method should allow the 31um Head to be centrally
located over the 58um Tape Track.
3 ) Tighten the Base Assembly A/C Head mounting Scre w.
VR168 - 923-03485
MECHANISM - VCR
Connection Point
Audio output jack
Connection Point
CH-1: PB RF Envelope
CH-2: NTSC: SW 30Hz
PAL: SW 25Hz
Head Switching Output
Test Point
RF Envelope Output Test
Point
3) If Folding or Curling is observed at the Top of it,
slowly turn the Tilt Adjustment Screw (C) counter-
clockwise.
NOTE: Check the RF Envelope after adjusting the A/C
Head, if the RF Waveform differs from Fig. C-5-4,
performs Precise Adjustment to flatten the RF
Waveform.
Test Conditions
(Mechanism Condition)
Play an Alignment Tape
1KHz, 7KHz Sections
1KHZ
A:Maximum
Fig. C-5-4
Test Conditions
(Mechanism Condition)
Play an Alignment Tape
Adjustment Diagram
X-Value Adjustment Hole
Azimuth Adjustment
Screw (A)
Connection Diagram
RF ENVELOPE OUTPUT TEST POINT
HEAD SWITCHING OUTPUT TEST POINT
4-17
Adjustment Point
7KHZ
B:Maximum
Adjustment Point
Groove at the
Base A/C
Left
Right
Tilt Adjustment Screw (C)
Height Adjustment Screw (B)
OSCILLOSCOPE
CH-1 CH-2
D35E COMBO - SERVICING