System Description Chapter 2

10-kW UHF Transmitter with Chapter 2, System Description
Feedforward Driver
840A, Rev. 0 2-13
Table 2-14. 10-kW Amplifier Assembly Fault Indicators
FAULT INDICATOR FUNCTION
Over Temp (DS22)
Indicates that the air temperature in the
exhaust stack is above 200° F as sensed
by the thermal switch (A15-S1) mounted
there. When this fault occurs, the voltages
will be immediately removed from the tube,
but the blower will continue running to
cool the transmitter.
VSWR Cutback (DS23)
Indicates that the reflected output power
of the transmitter, as sampled at (J15 - 1
and 2) of the transmitter control board, has
exceeded 10%; this causes the 10-kW
amplifier to cut back the output power level
needed to maintain a 10% visual reflected
level. If the reflected output power level
exceeds 15%, a VSWR fault will occur and
cause the transmitter to shut down.