7.2.2.2. ENVELOPE OUTPUT
ADJUSTMENT
The height of the S and T Posts replacement part is preset at
the factory.
Purpose: To achieve a satisfactory picture and
secure precise tracking.
Symptom of
Misadjustment:
If the envelope is output poorly, much
noise will appear in the picture. Then the
tracking will lose precision and the
playback picture will be distorted by any
slight variation of the tracking control
circuit.
1. Put the unit into the service mode "I. Tracking Fix" to defeat
Auto Tracking. Refer to "SERVICE MODE
SPECIFICATION" in "SERVICE NOTES."
2. Connect the oscilloscope to Pin 30 (Envelope signal) on the
TP Adjustment P.C.B. Use Pin 33 (Head Switch signal) as
a trigger.
3. Play back the Alignment Tape (VFMS0004H6C).
4. Confirm that the RF envelope is flat enough. If not, with Flat
Headed (—) Screwdriver, adjust S and T post height so that
the envelope waveform becomes as flat as possible (No
envelope drop). If the envelope drop appears on the left-
half of the waveform, adjust S post height. If the envelope
drop appears on the right-half of the waveform, adjust T
post height.
CAUTION:
Do not apply excessive pressure onto the S and T Posts
when adjusting S and T post height.
Fig. M3-1
Fig. M3-2
Note:
It will be possible to confirm step 4) after performing the
following steps.
a. Exit the "I. Tracking Fix" mode, then skip the "J. PG
Shifter" mode to enter other modes (except these 2). Or,
close the service mode.
b. Press the Tracking Control Up or Down button on the
camcorder. Make sure that the envelope waveform
remains flat. If not, readjust S and/or T post heights.
5. After adjustment, confirm that the tape travels without
curing at S and T posts.
If curing is apparent, readjust the height of posts.
Fig. M3-3
64
PV-D300 / VM-D100 / PV-L550 / PV-L600 / PV-L650 / VM-L450
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