Axcera INNOVATOR, Инструкция по эксплуатации

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UHF Analog Driver/Transmitter/ Chapter 2, System Description,
Translator Maintenance & Remote Control Connections
LX Series, Rev. 3 2-4
2.1.2 (A2) Modulator Module
Assembly (1301929; Appendix B)
NOTE: The Modulator module may not
be present in a translator system or in a
digital system.
NOTE : If both the Modulator and
Receiver are present in your system the
Modulated IF output from the Modulator
or Receiver must be selected. This is
accomplished by connecting a low or
removing the low to TB31-Pin 3 located
on the rear of the exciter/driver
assembly. By connecting the low, the
Modulator IF output is used by the IF
Processor module. By removing the low,
the IF from the internal or external
Receiver is used. (NOTE: The IF
Processor board must be configured for
external switching by placing jumper
W11 on J29 between pins 1 & 2).
The (A2) Modulator Assembly contains
the Modulator Board (1301797). The
modulator is broadcast quality and
provides front panel access to control and
monitoring points. The video level is
controlled through a sync tip clamp and
sync and white clipping circuitry. The IF
oscillator is oven controlled and locked to
a 10 MHz reference for stability. The IF
signal is fed through a SAW filter for
precise sideband shaping. The Modulator
operates using the baseband audio and
video inputs to produce a diplexed,
modulated, and on-channel frequency
aural RF output that is cabled to
the IF Processing Module.
Table 2-6. Modulator Front Panel Switch
SWITCH FUNCTION
MAN/AUTO CLAMP
SW1
When Manual Clamp is selected, the video level is set by the
Manual Bias Pot R67 located on the board. (
NOTE : The pot is
factory set and needs no adjustment by the customer).
When Auto Clamp is selected, the video level control circuit
will automatically increase or decrease the video to maintain
the desired video level.
Table 2-7. Modulator Front Panel Status Indicators
LED FUNCTION
AUR UNLOCK
DS5 (Red)
When lit it indicates that the 4.5 MHz VCO and the 10 MHz reference
are not PLL locked.
VIS UNLOCK
DS6 (Red)
When lit it indicates that the 45.75 MHz VCXO and the 10 MHz
reference signal are not PLL locked.
AUD OV DEV
DS4 (Red)
When lit it indicates the deviation level is more than ±80kHz
VIDEO LOSS
DS1 (Red)
When lit it indicates the Video Input to the transmitter is lost.