Nautel NV30LT-N, Руководство по эксплуатации и техническому обслуживанию

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NV30LT-N OPERATIONS & MAINTENANCE MANUAL DESCRIPTION
VERSION 0.1 2015-03-01 PAGE 3.1.5
30 kW RF Drive Splitter
The 30 kW RF drive splitter (A27) contains two stages of RF drive splitting. The RF drive source (A or B)
selected by relay K1 is applied to A27’s A1J1 input. The signal is first split into two inequal amplitude
signals (-4.8 dB and -1.8 dB) that are 90° out-of-phase. The -4.8 dB signal is applied to 10 kW RF drive
splitter assembly A19. The -1.8 dB signal is further split into two equal amplitude signals that are are
90° out-of-phase and then applied to 10 kW RF drive splitter assemblies A7 and A35. Cooling air is
provided by splitter fan 1 (B1).
A sample of the 30 kW RF drive signal is applied to the control/monitor stage, via the reject load/splitter
interface assembly (A28) for monitoring purposes.
10 kW RF Drive Splitters
The 10 kW RF drive splitters (A7, A19, A35 and A43) accept the outputs from the 30 kW RF drive splitter
(A27) and splits each output into four equal amplitude signals, using three 3 dB couplers connected in a
two-stage, binary splitting arrangement. The outputs of each of these splitters are applied to the 12 RF
power modules in the RF power stage. Attenuation values are set in order to balance the RF drive
output levels.
RF Power Stage
See electrical schematics Figure SD-8 through SD-10. The RF power stage accepts the intermediate RF
drive inputs from the RF drive stage and generates the final RF output. It consists of 12 RF power
modules, the module control/interface PWBs (A3, A18 and A34), three 10 kW combiner/filters (A12,
A24 and A40), a 20 kW combiner (A25), a 30 kW combiner (A26), output power probe (A15), 4-input 5
kW reject load assembly (A29), 4-input 10 kW reject load assembly (A31), 2-input final reject load
assembly (A13), reject load/splitter interface assemblies (A28 and A30) and part of 30 kW RF drive
splitter assembly (A27).
RF Power Module
See electrical schematic Figure SD-36. Each of the 12 RF power modules provides up to 3000 W of RF
output power. Each module contains four power amplifier (PA) PWBs (A1 through A4), a splitter/
interface PWB (A5), combiner PWBs (A6 and A7), and six cooling fans. The intermediate RF drive
outputs from the RF drive stage are applied to the RF power modules via the module control/interface
PWBs. Within each RF power module, the RF drive signal is sampled and then split to drive the module's
four PAs. The PA Volts inputs from the associated power supply modules control the RF output of the
four PAs. The RF power module provides critical signals (RF drive sample, reject power sample, heatsink
temperature, module presence and fan speeds) to the control/monitor stage for monitoring purposes.