Sony BVH-2000, Руководство по эксплуатации и обслуживанию

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(5-4-3. EQ-02 Board)
2.
DOG
Compensator (Q2,5,9,12)
RF
1)
The response near the RF carrier is and the
DG of the signal compensated for by varying the Q of the
emitter's resonance circuit
During playback, the RF switcher is switched by the RF SW
from the LG board and either of the channels is
thereby selected
3. PB RF 27,
DP Compensator (Q3,6,7,10,19 to 21,28,IC9)
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This circuit compensates for the frequency response of the
playback RF signals of the
RIP
video and
RIP
sync heads and
of the PLAY video and PLAY sync heads.
The DP is compensated
for simply by varying the
characteristics without inducing any change in the RF
amplitude characteristics.
4. Equalizer Controller (Q14 to 18,41,IC3,4,9)
A cosine equalizer is used to control the frequency response and
only the amplitude characteristics is controlled without inducing
any change in the phase characteristics.
When the AUTO/MANUAL switch Sl on the EQ-02 board is
set to MANUAL, the response of the equalizer is
controlled by the DC voltage corresponding to the settings of
the controls on the board When the same switch is set to
AUTO, the burst level is made constant by the DC voltage
corresnondmz to the level of the burst level from
the DM-25 board
Envelope detection for the RF is executed IC6 and the
detected RF envelope signal is output to the DT, MD and VM
boards. The DT board is used for
the
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The MD board is used for driving the VIDEO/RF meter. When
the meter switch Sl on the front of the MD board has been set to
RF(V), the envelope signal sampled by the timing of the video
channel is
the same switch has been set to
the envelope signal sampled by the timing of the sync channel is
output
The VM board first amplifies
the envelope signal and then
outputs it to the WFM MONITOR OUTPUT connector on the
connector panel.
VIDEO SIGNAL SYSTEM
6. Dropout Detector (Q37 to 40,IC8,14,21-26)
There are two types of dropout detector; one detects the level
cn;(HI!J~S
in the the other detects the dropouts from
the RF frequency.
Detection with shallow
in the RF takes place at
pin-4 of comparator IC8 and errors in the clamping of the sync
separauon on the DM board is nrevented.
Detection with deep dips in the
RF
envelope takes place at Pin-
9 of comparator IC8 and the is output to the time base
corrector.
The RF
is to the of
comparator IC8 while a voltage smoothed by RC network is
suppned to the ofIC8. When the level of the
RF envelope signal at the inverting input side drops even below
the reference
level of the side, this is
detected in the form of a dropout
The from the
RF
is detected by
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monostable multivibrator IC21. When this is triggered across
the normal frequency range, its output is active but when
triggered at a lower frequency than normal, an inactive interval
is caused and this is detected as a dropout
Furthermore,
the RF frequency varies in the shuttle mode and
so the time constant of the retriggerable monostable multivibrator
is varied by the speed level signal from the DM board and in
this way the detection level is compensated for.
When dropouts in the video or sync channel arising continuously
for 400- micro seconds or more are detected, the video lack or
sync lack signal is output to the LG board
5-4-6 BVH-2000(U/C)/PS/PM
BVH-2180(U/C)/PS/PM