Harris APEX - Page 14

APEX™ Exciter Incorporating FLO™ Technology
Table of Contents
Page: xii 888-2604-001 03/08/07
WARNING: Disconnect primary power prior to servicing.
4.3.2.1 44.4 MHz Phase Lock Loop . . . . . . . . . . . . . . . . .4-6
4.3.3 Exciter Output Spectral Response, RTAC Bypassed . . . . . . . . . . .4-6
4.4 APEX Exciter Analog Assembly Overview . . . . . . . . . . . . . . . 4-7
4.4.1 Up Converter Board Block Diagram Description. . . . . . . . . . . . .4-8
4.4.1.1 Up Converter Board UHF/VHF Band Pass Filter. . . . . . .4-8
4.4.2 Down Converter Board Block Diagram Description . . . . . . . . . . .4-9
4.4.3 PLL Board - A4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10
4.4.3.1 10 MHz Reference . . . . . . . . . . . . . . . . . . . . . 4-10
4.4.3.2 128.9 MHz IF PLL (First L. O.) . . . . . . . . . . . . . . 4-11
4.4.3.3 Main Phase Lock Loop (Second LO) . . . . . . . . . . . . 4-12
4.4.4 Output Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13
4.5 DC Power Distribution . . . . . . . . . . . . . . . . . . . . . . .4-14
4.5.1 Main Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14
4.5.2 Digital Deck Power . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14
4.5.2.1 Controller Board Power . . . . . . . . . . . . . . . . . . . 4-14
4.5.2.2 FPGA Modulator Board Power . . . . . . . . . . . . . . . 4-15
4.5.2.3 Adaptive Processing Board Power . . . . . . . . . . . . . 4-15
4.5.2.4 Power for DAC and ADC Boards. . . . . . . . . . . . . . 4-15
4.5.2.5 External I/O Board Power. . . . . . . . . . . . . . . . . . 4-16
4.5.2.6 Front Panel Board . . . . . . . . . . . . . . . . . . . . . . 4-16
4.5.3 Analog Deck Power . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16
4.5.3.1 UDC Interface Board Power . . . . . . . . . . . . . . . . 4-16
4.5.3.2 Exciter Cooling Fan Power . . . . . . . . . . . . . . . . . 4-16
4.5.3.3 Down Converter Board Power . . . . . . . . . . . . . . . 4-17
4.5.3.4 PLL Board Power . . . . . . . . . . . . . . . . . . . . . . 4-17
4.5.3.5 Up Converter Board Power . . . . . . . . . . . . . . . . . 4-18
4.5.3.6 Output Amplifier . . . . . . . . . . . . . . . . . . . . . . 4-18
5 Maintenance and Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
5.1 Exciter Maintenance . . . . . . . . . . . . . . . . . . . . . . . . 5-1
5.1.1 Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-1
5.1.2 Measuring PLL Board Frequencies . . . . . . . . . . . . . . . . . . . .5-6
5.1.2.1 Measuring Center Channel Frequency . . . . . . . . . . . .5-6
5.1.2.2 PLL Board 10 MHz Reference Oscillator Frequency. . . . .5-8
5.1.2.3 Measuring the 1st Local Oscillator Frequency . . . . . . . .5-8
5.1.2.4 Measuring the 2nd Local Oscillator Frequency. . . . . . . .5-8
5.2 Loading Software . . . . . . . . . . . . . . . . . . . . . . . . . 5-9