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Chapter 5 435 – 480 MHz UHF2 Theory of Operation
5.1
Introduction
This chapter provides a detailed theory of operation for the radio components. Schematic diagrams
for the circuits described in the following paragraphs are located in Chapter 7 of this manual.
5.2
UHF2 Receiver
The UHF2 receiver design covers the frequency range of 435 – 480 MHz and it is a double
conversion super heterodyne with 1st IF 45.1 MHz and 2nd IF 455 kHz. The receiver is divided into
two major blocks, Front End and Back End as shown in Figure 5-1.
Figure 5-1. UHF2 Receiver Block Diagram
Crysta
l
F
i
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ter
Crysta
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44.64
5M
Hz
1st
Mi
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er
RF
A
mp
Prese
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ector
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ter
Postse
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ector
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irst
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rom
Synt
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esi
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er
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IF
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P
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Ceramic
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i
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ter
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escriminator
4
55
FW
4
55
HW
Qu
a
d
rat
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re
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etector
R
SS
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N
/S
_
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W
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io
4
55C2
4
Содержание P100 Series
Страница 1: ...P100 Series Portable Radios Detailed Service Manual ...
Страница 2: ......
Страница 8: ...iv Notes ...
Страница 18: ...xiv List of Tables Notes ...
Страница 22: ...xviii Summary of Printed Circuit Boards and Bands Available Notes ...
Страница 30: ...Notes 2 4 Test Equipment Service Aids and Service Tools Service Aids ...
Страница 54: ...7 4 UHF2 Schematic Diagrams Overlays and Parts Lists Speaker and Microphone Schematic Notes ...
Страница 128: ...7 78 Circuit Board Schematic Diagram and Parts List UHF2 435 480 MHz Notes ...
Страница 150: ...7 100 Circuit Board Schematic Diagram and Parts List UHF2 MDC QCII R TTE 435 470 MHz Notes ...
Страница 166: ...10 4 VHF Schematic Diagrams Overlays and Parts Lists Speaker and Microphone Schematic Notes ...
Страница 192: ...10 26 Circuit Board Schematic Diagram and Parts List VHF 136 174 MHz Notes ...
Страница 218: ...10 52 Circuit Board Schematic Diagram and Parts List VHF 136 174 MHz Notes ...
Страница 242: ...10 76 Circuit Board Schematic Diagram and Parts List VHF MDC QCII R TTE 136 174 MHz Notes ...
Страница 258: ...13 4 UHF1 Schematic Diagrams Overlays and Parts Lists Speaker and Microphone Schematic Notes ...
Страница 261: ...Circuit Board Schematic Diagram and Parts List UHF1 403 447 MHz 13 7 Figure 13 5 Transmitter Schematic Diagram ...
Страница 328: ...13 74 Circuit Board Schematic Diagram and Parts List UHF1 MDC QCII R TTE 403 447 MHz Notes ...
Страница 332: ...A 4 Warranty Service Support and Replacement Parts Further Assistance From Motorola Notes ...
Страница 335: ......