3-3
CCU-590/P/V1(E)
TR-133B Board
The TR-133B board demodulates the RF signals of MIC1, MIC2, INCOM1, INCOM2, CAM DATA, and
TONE transmitted from the camera, and modulates the PGM1, PGM2, INCOM1, INCOM2, CCU
DATA, and H CONT signals to transmit them to the camera. In addition, this board also modulates
RETURN VIDEO and PROMPT VIDEO (and AUX VIDEO as well by selection).
H CONT Modulator Circuit
This circuit modulates the H CONT signal transferred from the IV-57B board. H CONT is a control
signal to match the H phases of camera SG and CCU SG. The oscillation frequency varies with the H
CONT signal voltage. The RF signal modulated in the modulator circuit is merged with other RF signals
through the buffer and the band pass filter (BPF).
CCU DATA Modulator Circuit
This circuit modulates the CCU DATA signal transferred from the AT-155B board. As in the H CONT
modulator circuit, the modulated RF signal is merged with other RF signals through the buffer and the BPF.
INCOM Modulator Circuit
This circuit D/A converts the INCOM1 and INCOM2 signals transferred from the AU-295 board, and
filters the analog signals with the LPF, and then modulates them. As in the H CONT modulator circuit,
the modulated RF signal is merged with other RF signals through the buffer and the BPF.
CAM DATA/TONE Demodulator Circuit
This circuit has functions for demodulation of the CAM DATA/TONE signals transferred from the
camera to CCU-590, shaping the CAM DATA signal waveform, and for TONE detection. The RF signal
whose modulation frequency is 5.6 MHz is demodulated by the FM demodulator IC. The CAM DATA is
shaped after the residual carrier is eliminated, and is then sent to the AT-155B board. The TONE signal
transferred to the TONE detector circuit is used to control ON/OFF of 180 VDC supplied from CCU-590
to the camera.
MIC1/2 Demodulator Circuit
This circuit demodulates the MIC1, MIC2 signals transferred from the camera to CCU-590. The RF
signal whose modulation frequency is 6.2/6.7 MHz passes through the BPF, and is then demodulated by
the FM demodulator IC. Then the residual carrier is eliminated by the LPF, and the demodulated signal is
A/D converted and is then output to the AU-295 board.
INCOM Demodulator Circuit
The RF signal whose modulation frequency is 7.1 MHz or 7.4 MHz is demodulated by the FM demodula-
tor IC in the same way as the MIC signals. The demodulated signal passes through the LPF, is A/D
converted, and is then output to the AU-295 board.
Prompter Modulator Circuit
This circuit performs AM modulation of the VBS signals input from the PROMPT VIDEO connector on
the rear panel, and then sends the signal to the CA. The input VBS signal passes through the buffer, LPF,
and the clamp, and is AM modulated by the modulator IC, and is then amplified by the RF amplifier. The
RF amplifier gain is controlled using the compensation data (cable length) provided from the DM-140
board. The signal is transferred further to the RF amplifier and the 100 MHz BPF, and is then output.
RETURN Modulator Circuit
This circuit performs FM modulation of the VBS signal that is input from the RET1 through RET4
connector on the rear panel and is processed (Y mixing) on the IV-57B board, and then sends the signal to
the CA. The input VBS signal passes through the buffer, LPF, and the clamp, and is then amplified. It is
then FM modulated by the modulator IC through the buffer. The modulation wave gain is also controlled
using the cable length data like the prompter modulator circuit.
