User's Manual
300-Watt Digital UHF Transmitter Chapter 2, System Description
DT830A, Rev. 1 2-7
Table 2-11. UHF Amplifier Tray Status Indicators
INDICATOR FUNCTION
Enable (DS4 green)
Indicates that an Enable, Operate,
command is applied to the UHF amplifier
tray from the UHF exciter tray
Overdrive (DS2 red)
Indicates that the level of the drive is too
high. The protection circuit will limit the
drive to the set threshold. The fault is
generated on the amplifier control board.
VSWR cutback (DS1 red)
Indicates that the reflected power level of
the tray has increased above 50%, which
will automatically cut back the output power
level to 50%. The fault is generated on
the amplifier control board.
Overtemp (DS3 red)
Indicates that the temperature of (A5-A6-
A3 and A5-A6-A4) one or both of the two
thermal switches mounted on the heatsink
assembly for the output amplifiers is above
175° F. When this fault occurs, the Enable
to the switching power supply in the
affected amplifier tray is removed
immediately and it will shut down.
Input fault (DS5 red)
Indicates that the input RF level to the
amplifier tray dropped below 0 dBm
Table 2-12. UHF Amplifier Tray Controls
CONTROL FUNCTION
Phase (A10-R5)
Adjusts the phase of the RF output with a
range of approximately 90°
Gain (A11-R6)
Adjusts the gain of RF output when the
amplifier control board is in the AGC mode
Table 2-13. UHF Amplifier Tray Sample
SAMPLE DESCRIPTION
Module O/P (0 dBm)
A sample of the combined output of the
four dual-stage amplifier boards taken
from the dual peak detector board
2.3 Remote Connections
The IF input to the transmitter connects
to the rear of the UHF exciter or to (A12)
the input and remote interface panel
(Figure 2-1). Jacks J10 and J11 on the
rear of the UHF exciter provide
connections for the remote monitoring
and operation of the transmitter. Jack
J11 should have a dummy plug
connected to it with a jumper between
pins 23 and 24 that provides the
interlock needed to operate the
transmitter. If remote connections are
made to the transmitter, they should be
made through the plug in J10 or J11 in
the positions noted on the interconnect
drawing (1127833).