Flashcards in SSPA Deck (43):
What is the function of the SSPA?
to perform high-power amplification of either internally or externally generated and modulated signals and coupling to the DTWA subsystem
The SSPA amplifies low-level RF signals in the frequency range of...
17 - 60 KHz
What is the output power of the SSPA?
200 KW (200,000 W)
Where is the Automatic Control Head (ACH) located?
Primary- SSPA/C Module Shelf Rack
Remote- P30 Bay 4
What is the function of the ACH?
to provide a visual presentation of the operation and status of the SSPA/C during automatic operation/
primary interface between operator & SSPA
Where is the Computer Input and Output (I/0) located?
1A3 rack of SSPA/C
What is the function of the Computer I/O?
to receive sensory inputs and send commands for control and monitoring of the SSPA/C in the automatic mode/
interface between ACH and SSPA/C
Where is the Local Maintenance Panel (LMP) located?
1A2 rack of SSPA, next to ACH
What is the function of the LMP?
to manually control and display the primary operational status of the SSPA/C
What is the range of the LOAD and TUNE meters?
-5 to +5
What is the range of the ANT VOLTAGE meter?
0 to 25 kV pk
What is the range of the ANT CURRENT meter?
0 to 30 A
What is the range of the OUTPUT POWER meter?
0 to 220 KW
TEMP WARN indicator illuminates yellow when the SSPA/C temperature exceeds...
165 degrees F
PA HOT indicator illuminates red if the PA temperature exceeds...
185 degrees F
Where are the two Input Modules located?
first shelf of the 1A1 rack of SSPA/C
What is the function of the IMs?
to perform modulation, conditioning, and routing of the input VLF signal to the MPDG
When used in the internal mode, the IM generates a Stabilized Master Oscillator (SMO) output signal of...
715 to 801 KHz
IM output is a...
modulated sine wave
Where is the Multiple Phase Drive Generator (MPDG) located?
1A1 rack of SSPA/C, aft of the IMs
What is the function of the MPDG?
to receive sine wave RF signals from the selected IM and convert the input signal into phased rectangular waves to be amplified by the PAMs
Where are the Power Amplifier Modules (PAMs) located and how many are there?
throughout the three SSPA/C module shelf racks;
32, 4 associated with each HVPS
What is the function of the PAMs?
to receive and amplify a rectangular waveform from the MPDG;
then output the amplified signal to the primary windings of its Combiner Transformer to be further amplified and combined wit other PAM outputs
The Printed Wire Assembly (PWA) in each PAM...
receives the MPDG drive signals and conditions and routes them to the left and right Field Effect Transistors (FETs) Driver Bards
The 2 FET Driver PWA Boards...
interface the output of the control monitor board and the gate circuits of the 32 Power FETs, and provide the FETs' on/off condition
The 32 Power FETs (arranged in a bridge formation)...
8 FETS, arranged in parallel, make up each bridge leg, which functions like an on/off switch that is controlled by signals from the MPDG
Where is the Servo Discriminator located?
1A3 rack of SSPA/C
What is the function of the Servo Discriminator?
to control the Coupler Network variometers by monitoring voltage and current samples at the Coupler Network input and processing those samples into tune and load error signals
Where are the High Voltage Power Supplies (HVPSs) located and how many are there?
HVPSs 1, 2, 3 - 1A1 rack
HVPSs 4, 5, 6 - 1A2 rack
HVPSs 7, 8 - 1A3 rack
What is the function of the HVPSs?
to rectify the three-phase 115 VAC, 400 Hz input power to provide the following voltages to the four PAMs associated with that HVPS:
270 VDC (+135 and -135 VDC)
The low voltage outputs (+24 VDC and -10 VDC) are referenced to the _____ output.
Where are the Low Voltage Power Supplies (LVPSs) located and how many are there?
What is the function of the LVPSs?
to rectify the three-phase, 115 VAC, 400 Hz input power to supply the following voltages to all the SSPA/C modules, with the exception of the PAM:
Where are the Combiner Transformer Assemblies located and how many are there?
inside the SSPA/C enclosure on the rear wall of each of the three network bays; 8 total
1, 2, 3 in right (fwd) bay
4, 5, 6 in center bay
7, 8 in left (aft)
What is the function of the Combine Transformer Assembly?
to combine the output power of all the 32 PAM units by voltage addition and rout the signal to the Coupler Network
Where is the Coupler Network located?
all three network bays
What is the function of the Coupler Network?
to receive the voltage sum of the Combiner Transformer Assembly secondaries and use the band select capacitors and two variometers to match the output impedance of those secondaries to the input impedence of the DTWA
Where are the RF Transmission Lines located?
Starboard aft wall of SSPA/C enclosure
What are the power requirements for the RF Transmission Lines?
What is the function of the RF Transmission Lines?
to convey the fully amplified VLF Transmit signal (RF energy) from the SSPA/C to the STWA
Where is the SSPA/C Cooling System (Forced Air Cooling) located?
Flight Engineer's Station; flight deck
What are the power requirements for the FAC?
28 VDC from VLF PWR AMP on P67-3