2: System Overview
2-2
PRC1099A-MS
2.2
DDS Synthesizer
The DDS synthesizer outputs two local oscillator frequencies and a beat
frequency oscillator (BFO) frequency that it derives from a single reference
oscillator. The first local oscillator frequency (LO1) is a variable output
ranging from 76.6 to 105 MHz in 1 Hz steps. The second local oscillator
(LO2) is a fixed output frequency is 73.35, and the BFO is either 1647 kHz
(LSB mode) or 1650 kHz (USB mode),
2.3
Processor Control
The processor controls the DDS synthesizer, display, antenna tuner and many
other functions using the firmware program stored in permanent read-only
memory (ROM). Programmable functions such as channel frequencies and
antenna tune information are stored in random access memory (RAM). A
lithium battery with a nominal life of ten years provides DC power backup for
the RAM.
The serial peripheral interface (SPI) bus delivers data and control signals to
the appropriate boards. The data is decoded on the individual boards. The
front panel controls also interface with the processor to control and configure
radio functions. The serial data extends to the Accessory connector to control
external accessories such as a RF power amplifier.
Figure 2-1 Frequency Conversion Plan
Receiver Input
1.6 to 30 MHz
Audio
Output
To final amplifier
1.6 to 30 MHz
Microphone
Input
Transmit Path
Receive Path
Low Pass
Filter
1.6 to 30 MHz
Mixer
Output
75 MHz
75 MHz
Crystal
Filter
Mixer
Output
1650 kHz
1650 kHz
Crystal
Filter
Product
Detector
Synthesizer
First Loop
76.6 to 105 MHz
in 1 Hz Increments
Low Pass
Filter
1.6 to 30 MHz
Mixer
Output
1.6 to 30 MHz
75 MHz
Crystal
Filter
Mixer
Output
75 MHz
1650 kHz
Crystal
Filter
Balanced
Modulator
Synthesizer
Second Loop
73.35 MHz
BFO
1650 KHz USB
1647 KHz LSB
Содержание PRC1099A
Страница 4: ......
Страница 8: ......
Страница 35: ......
Страница 49: ...3 Audio Filter Board 3 14 PRC1099A MS Figure 3 2 Audio Filter Board Component Locations 738221 Rev J ...
Страница 65: ......
Страница 71: ...4 1650 kHz IF Board 4 6 PRC1099A MS Figure 4 2 1650 kHz IF Board Component Locations 738028 Rev D ...
Страница 76: ......
Страница 86: ...5 Mixer Board 5 10 PRC1099A MS Figure 5 4 Mixer Board Component Locations 738217 Rev H ...
Страница 97: ......
Страница 103: ...6 Power Amplifier Board 6 6 PRC1099A MS Figure 6 2 Power Amplifier Board Component Locations 738617 Rev C ...
Страница 117: ...7 Antenna Tuner Board PRC1099A MS 7 9 Figure 7 2 Antenna Tuner Driver Board Component Locations 738346 Rev B ...
Страница 118: ...7 Antenna Tuner Board 7 10 PRC1099A MS Figure 7 3 Antenna Tuner Board Component Locations 738027 Rev D ...
Страница 125: ......
Страница 131: ...8 Synthesizer Board 8 6 PRC1099A MS Figure 8 2 Synthesizer Board Component Locations 738025 Rev A ...
Страница 163: ...9 Processor Board 9 14 PRC1099A MS Figure 9 2 Processor Board Component Locations 738218 Rev B ...
Страница 178: ...10 Display Board 10 8 PRC1099A MS Figure 10 1 Display Board Component Location Diagram 738220 Rev G ...
Страница 181: ......
Страница 185: ...11 Junction Board 11 4 PRC1099A MS Figure 11 1 Junction Board Component Locations 738222 Rev F ...
Страница 200: ......
Страница 207: ...13 Internal Options PRC1099A MS 13 7 Figure 13 3 ALE Board Component Locations 1 of 2 738215 Rev B ...
Страница 208: ...13 Internal Options 13 8 PRC1099A MS Figure 13 4 ALE Board Component Locations 2 of 2 738215 Rev B ...
Страница 241: ......
Страница 247: ...Index 6 T Technical specifications 1 2 Transmit path 2 4 U USB 1 4 see also Modulation modes USB LSB mode V VSWR 1 4 ...