Chapter 3 Theory Of Operation; Main Board; Main Board Major Sections; Vhf (136-174 Mhz) Band - Motorola ASTRO Digital XTL 5000 Detailed Service Manual

Chapter 3 Theory of Operation

3.1

Main Board

This section provides a detailed circuit description of the XTL 5000 radio main board for VHF/UHF
Range 1/UHF Range 2/700–800 MHz models. The main board contains the following major
sections:
• Radio Power
• Receiver Front-End
• Receiver Back-End
• Transmitter
• Frequency Generation Unit
• Controller
When reading the theory of operation, refer to your appropriate schematic and component location
diagrams located in
detailed Theory of Operation will help isolate the problem. However, first use the ASTRO Digital
XTL 5000 VHF/UHF Range 1/UHF Range 2/700–800 MHz Mobile Radio Basic Service Manual
(6881096C73) to troubleshoot the problem to a particular board.
3.2

Main Board Major Sections

This section contains the main board layouts for each radio frequency band.
3.2.1 VHF (136–174 MHz) Band
The illustrations
(Table 3-1 on page 3-2
main board.
(page 3-12)
(page 3-13)
(page 3-20)
(page 3-26)
(page
(page 3-62)
"Chapter 7. Schematics, Component Location Diagrams, and Parts
(Figure 3-1 on page 3-2
to Table 3-4 on page
3-45)
to Figure 3-4 on page
3-5) identify the location of the major sections of the
3-5) and their accompanying tables
Lists". This