Axcera 430B, Manual

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Axcera-430A FCC Type Acceptance Report Operational Description
February 2004 8-9
Table 8-7. VHF High-Band Amplifier Tray Fault Indicators
INDICATOR DESCRIPTION
Overdrive (DS1)
Indicates that the level of drive is too high.
The protection circuit will limit the drive
level to the set threshold. The fault is
generated on the overdrive protection
board.
Enable (DS2)
Indicates that the enable supplied by the
exciter tray is present
Module Status (DS3)
Indicates that the forward power sample
level is lower than the set reference level
VSWR Cutback (DS4)
Indicates that the reflected level of the
tray has increased above 20%; this will
automatically cut back the output power of
the tray. The fault is generated on the
AGC control board.
Overtemp (DS5)
Indicates that the temperature of (A4-A5,
A4-A6, or A5-A2) the thermal switch is
above 80
° C. When this fault occurs, the
enable to the switching power supply is
immediately removed.
Table 8-8. VHF High Band Amplifier Tray Control Adjustments
ADJUSTMENT DESCRIPTION
Phase (A7-R2)
Adjusts the phase of the RF output by
approximately 70%
Gain (A6-R3)
Adjusts the gain of the RF output when the
amplifier control board is in the AGC mode
Table 8-9. VHF High Band Amplifier Tray Sample
SAMPLE DESCRIPTION
RF Front Panel Sample
Forward power sample of the tray from the
AGC control board
8.6 Input and Remote Connections
The baseband video and audio inputs alone or, if the (optional) 4.5-MHz composite
input kit is purchased, the 4.5-MHz composite input or the baseband video input and
audio input to the transmitter, connect to the rear of the VHF exciter tray. The
baseband video input or the 4.5-MHz composite input connects to jacks J1 or J2, which
are loop-through connected. The baseband audio input connects to TB1 for balanced
audio or to jacks J3 or J13, which are loop-through connected, for composite, stereo,
audio. To use the 4.5-MHz composite input kit, the baseband audio can remain
connected to the VHF exciter even if the 4.5-MHz composite input kit is used, but the
baseband video must be disconnected from J1 or J2 and the 4.5-MHz composite input
must be connected to J1 or J2. The baseband select command must be removed from
J7-6 and J7-7.