AEA PAKRATT PK-232, Technical Reference Manual

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PK-232 TECHNICAL MANUAL CHAPTER 3 – THEORY OF OPERATION
PK232TM Rev. A 5/87 3-1 Page 11
CHAPTER 3 – THEORY OF OPERATION
3.1 System Diagrams
Please refer to APPENDIX C for the various diagrams used as reference in this chapter.
3.1.1 Block Diagrams
Refer to the Functional Block Diagram, Figure 1 in APPENDIX C. Dashed lines separate the
five sections of the PK-232. Each section will be described separately and is labeled as fol-
lows:
o Analog
o Digital
o Input/Output (I/O)
o Display
o Power Distribution
3.1.2 Logic Diagrams
Refer to the Logic Diagram, Figure 2 in APPENDIX C. Figure 2 shows the digital logic por-
tion of the PK-232 which includes:
o the microprocessor
o Read Only Memory (ROM)
o Random Access Memory (RAM)
o clock and control logic
o part of the display logic
o the logic associated with the digital communications between the PK-
232 and the terminal.
The major portion of the power distribution section is also shown on this drawing.
3.1.3 Schematic Diagrams
Refer to the Schematic Diagram, Figure 3 in APPENDIX C. Figure 3 shows the analog por-
tion of the PK-232, which includes:
o mode-dependant bandpass filters
o MARK and SPACE resonators
o audio frequency discriminator
o mode-dependant low pass filter
o comparator circuitry
o AFSK generator
o watchdog time
o transmitter audio driver
o keying circuitry
o radio switching
o tuning indicator circuitry