System Description Chapter 2

10-kW UHF Transmitter with Chapter 2, System Description
Feedforward Driver
840A, Rev. 0 2-7
2.2.3 250-Watt Amplifier Trays
Table 2-8. 250-Watt Amplifier Tray Meters
METER FUNCTION
Reads power in terms of a percent of the calibrated power
output value. A full-scale reading is 100%, which is equivalent
to the full-rated 250 watts peak of sync visual + aural output
power. Also reads % Reflected Power, power supply voltage
levels, and AGC voltage levels.
With Switch S1 in
Position
Display
Switch (S1), Meter
Selects the desired % Power or the
voltage reading
% Output Pwr
Reads the % Output Power of the
tray (100%=250 watts peak of sync
visual with -10 dB aural on the top
scale)
% Refl (Reflected)
Reads the % Reflected Output Power
of the tray (<10%)
Meter (A12)
Power Supply
Reads the power supply voltage,
+26.5 VDC, on the middle scale
Table 2-9. 250-Watt Amplifier Tray Status Indicators
STATUS INDICATOR FUNCTION
Enable (DS1 Green)
Indicates that an Enable, Operate,
command, is applied to the UHF amplifier
tray from the selected UHF exciter tray
Overtemp (DS2 Red)
Indicates that the temperature of (A1-A7
and A1-A8), 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
will shut down.