Sony BVH-2000, Руководство по эксплуатации и обслуживанию

Страница: 275 / 505

(5-3-2. AP-06/12 Board)
2.
In otder to reduce the variations in the recording current, which
are
fluctuations the
RIP
head's the
RIP
head is inserted into the feedback loop of the REC
amplifier and a constant-current circuit is configured. The
the connector are tmpedance-
matched by the LA board, their recording level is by
the VR board, and they are input to the REC amplifier on the
AP board through the REC amplifier on the AU board.
bias
from the board is added the
recording signal and supplied to the
RIP
head.
REC SIG IN
BIAS IN
-+---...- .......
I\,'\I'---.--....J
z
o
~
«
a:
w
0...
o
LL
o
>-
a:
o
w
I
~
LO
3.
This circuit configures a feedback type of equalizer amplifier
based on a 2-stage differential amplifier.
In order for time code to be back at
speed, the AUDIO-3 channel frequency response is linearly
extended up to a higher range than that of the other channels.
FREQUENCY RESPONSE OF AUDIO CH-1/2/4
GAIN
6dB/OCT
30d 8
t.---+----~
50Hz 10.6KHz 1KHz
FREQUENCY RESPONSE OF AUDIO CH-3
GAIN
- 6dB/ OCT
30dB I---+-----~
50Hz
120KHz 1KHz
AUDIO SIGNAL SYSTEM
Audio Monitor Arnnuner
The AUDIO-l/2/4 amplifier gain is 48 dB at 1 kHz, but since
the of the channel head is 6 dB
lower than that of the other channels, the amplifier gain of this
channel is 54 dB. In order to suppress the power line noise, a
filter is used in each of the channels.
5. CTL EC Amplifier
The REC CTL signal is produced by the CD board based on the
REF 4F signal of the SR board and on the REF 2F signal of the
board, and it is to the board. The CTL
signal is amplified to the prescribed level, bias (198.9 kHz) is
applied to the signal in order to reduce the recording current,
and the signal is
through the CTL
RIP
head for
saturated recording on the tape. By applying bias to the REC
CTL signal, it is possible to reduce the effects of the CTL on the
AUDIO-3 channel.
6. CTL PB Amplifier
The PB CTL signal, which has been played back by the CTL
RIP
head, is supplied to the CD board and the color frame is
detected from its phase relationship with the capstan FG.
suppned PB is first
amnuneo
the CD board and then, in order to correct the tape timer by
CTL, it is output to the RL board.
is switcher which switches the response to the
value with 1x normal speed playback and to the value with any
other speed. In order to reduce bias leak from the AUDIO-3
channel, bias trap Q502 is activated when
tape is played back
at normal
Since the level of the CTL signal played back in the
PAL/SECAM model is low, the fluctuations in the DC level
must be do so, Q503 is switched on the
NORMAL FWD signal during l x normal speed playback and
the low-range frequency response is reduced.
5-3-2 BVH-2000( U/C)/PS/PM
BVH-2180(U/C)/PS/PM