5. To shift the CTL waveform, press CH UP or CH4. If the envelope is as shown in Fig. M8, adjust the
DOWN button on the remote control unit. Then makeheight of Guide Roller [3] (Refer to Fig. M3) so that the
sure that the maximum output position of PB FMwaveform looks like the one shown in Fig. M9.
envelope signal become within ?2ms from preset
5. When Guide Rollers [2] and [3] (Refer to Fig. M3) are
position.
aligned properly, there is no envelope drop either at
the beginning or end of track as shown in Fig. M9.
Good
Dropping envelope level at the beginning of track.
FM envelope signal
2ms
Center Position
CTL signal
FM envelope output signal
Fig. M8
is adjusted at maximum.
No GoodDropping envelope level at the end of track.
FM envelope output signal is low.
Fig. M7
6. Set the Tracking Control Circuit to the preset position
by pressing CH UP button on the remote control unit.
Fig. M9
and then "PLAY" button.
1-C. Checking/Adjustment of Enve-
Envelope is adjusted properly. (No envelope drop)
lope Waveform
Purpose:
To achieve a satisfactory picture, adjust the PB FM
envelope becomes as flat as possible.
Symptom of Misalignment:
If the envelope output is poor, noise will appear in the
picture. The tracking will then lose precision and the
Fig. M10
playback picture will be distorted by any slight variation
of the Tracking Control Circuit.
Note: Upon completion of the adjustment of Guide
1. Connect the oscilloscope to TP301 (C-PB) on the
Rollers [2] and [3] (Refer to Fig. M3), check the X Value
Main CBA. Use TP504 (RF-SW) as a trigger.
by pushing the CH UP or DOWN buttons alternately, to
2. Playback the Gray Scale on the Test Tape (FL6NS8).check the symmetry of the envelope. Check the number
Set the Tracking Control Circuit to the preset positionof pushes to ensure preset position. The number of
by pressing CH UP button and then "PLAY" button onpushes CH UP button to achieve 1/2 level of envelope
the unit. Adjust the height of Guide Rollers [2] and [3]should match the number of pushes CH DOWN button
(Fig. M3, Page 2-3-3) watching the oscilloscope dis-from center. If required, redo the "X Value Alignment."
play so that the envelope becomes as flat as possible.
To do this adjustment, turn the top of the Guide Roller
with the Guide Roller Adj. Screwdriver.
3. If the envelope is as shown in Fig. M7, adjust the
height of Guide Roller [2] (Refer to Fig. M3) so that the
waveform looks like the one shown in Fig. M9.
2-3-4H9740MA |
ACEC
SHARP
