Motorola CP180 Informazioni sul servizio - Pagina 9

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Anche per Motorola CP180: Manuale d'uso di base (16 pagine), Manuale d'uso di base (16 pagine), Manuale d'uso di base (18 pagine), Manuale di servizio dettagliato (28 pagine), Manuale di installazione di Cps/Tuner (6 pagine), Informazioni sul servizio (46 pagine)

Motorola CP180 Informazioni sul servizio
1.0

Introduction

This Chapter provides a detailed theory of operation for the UHF circuits in the radio. Schematic
diagrams and board layout diagrams are included in Chapter 4 in this Section of the manual.
2.0
UHF (438-470MHz) Receiver
The UHF receiver covers the range of 438-470 MHz and provides switchable IF bandwidth for use
with 20/25/30 kHz or 12.5 kHz channel spacing systems. The receiver is divided into two major
blocks, as shown in Figure 2-1.
Front End
Back End
RX from
Antenna Switch
Preselector
RF
Filter
Amp
First LO
from Synthesizer
Recovered Audio
RSSI
Figure 2-1 UHF Receiver Block Diagram

THEORY OF OPERATION

Interstage
Crystal
Filter
1st Mixer
Inj Filter
6G
Ceramic
Resonator
Demodulator
12.5kHzFilter
Chapter 2
IF
Amp
Filter
BW_SEL
6E
Cer Fltr
Switching
4E