AR 10036484, Operating And Service Manual, Page: 47 / 58

Model 3000W1000B
Rev A 31
3.2.6 Power Supplies, Driver Amplifier (PS1 and PS2)
Power supply PS1 supplies a +5VDC housekeeping supply for the control system assemblies A12 Control
Panel Assembly and A13 ALC board.
PS1 also su23 VDC at 10 amps, +12 VDC at 13 amps, -12 VDC at 5 amps. PS1 is a switching
supply that automatically sets the AC input circuits to the correct connections for the line voltage 90-264
VAC input ranges 47-440 Hz.
The +23 VDC at 10.0 amp power supply is fed to the A1 Pre-Amplifier to supply the FET drain voltage for
this amplifier. The +12 VDC at 13 amps is for fans B1 through B5.
The –12 V at 5 amps power supply is fed to the A1 Pre-Amplifier, A2, A4-A6 Driver Modules to provide
gate voltage for these modules.
PS2 su23 VDC at 44 amps. PS2 is a switching power supply that automatically sets the AC input
circuits to the correct connections for the line voltage 120-240 VAC, 50-60 Hz.
PS2 su23 VDC to amplifiers A2, A4-A6 to provide the drain voltage for these amplifiers.
3.3 RF AMPLIFIER OPERATION (500 WATT POWER AMPLIFIER
SCHEMATIC, 10039099)
3.3.1 A4 Two-Way Splitter
The Two-Way splitter splits the input signal into two equal-amplitude, equal-phase signals. The amplitude of
each signal is 3–3.5 dB below the input signal when both outputs
are terminated into 50Ω loads.
3.3.2 A5, A6 Four-Way Splitters
Each Four-Way splitter splits the input signal into four equal-amplitude, equal-phase signals. The amplitude
of each signal is 6–6.5dB below the input signal when both outputs are terminated
into 50Ω loads.
3.3.3 A7-A14 Final Amplifiers (Schematic 10036697)
Each A7-A14 Final Amp consists of RF matching circuits, an RF transistor a DC current control circuit, a
DC switching circuit and a fault detection circuit.
The RF input is fed to a 4:1 transformer composed of T1, T2, and T3. The push-pull output signal of the 4:1
transformer is connected to the gates of push-pull connected Q1. The drains of Q1 are connected to a 4:1
transformer composed of T4, T4 and T6. The RF transistor , Q1, has approximately 22.5 VDC applied to the
drains at 4 amps current for the driver and 7 amps current for the finals. The RF stage has approximately 18
dB of gain for the finals and an output compression point of 50 watts or greater from final amplifiers A6-
A13.