Icom IC-271A Manuals

Manuals and User Guides for Icom IC-271A. We have 3 Icom IC-271A manuals available for free PDF download: Maintenance Manual, Service Manual, Instruction Manual

Icom IC-271A Maintenance Manual (148 pages)

144 Mhz

Brand: Icom | Category: Transceiver | Size: 24.14 MB

Table of Contents
2
Specifications
3
General
3
IC-271 Versions Available
4
Control Functions
5
Front Panel
5
Rear Panel Connections (IC-271 A/E)
8
Accessory Socket Connections
8
Outside View
8
Rear Panel Connections (IC-271 H)
9
Controls under the Access Cover
10
Inside Views
11
Top View (IC-271 A/E)
11
Bottom View (IC-271 A/E)
12
PLL (HPL) Unit (Located under the Logic Unit)
12
Top View (IC-271 H)
13
Bottom View (IC-271 H)
14
Block Diagrams
15
IC-271 A/E
15
IC-271 A/H
17
Circuit Description
19
Receiver
19
RF Circuit (RF-YGR Unit)
19
Intermediate Frequency Circuit (Main Unit)
19
BFO Circuit (Main Unit)
20
Noise Blanker Circuit (Main Unit)
20
Audio and Squelch Circuits (Main Unit)
20
S-RF Meter Circuit (Main Unit)
20
Transmitter
21
Audio Amplifier and Limiter Circuits (Main Unit)
21
Buffer Amplifier Circuit (Main Unit)
21
Vox Control and CW Break-In Circuits (Main Unit)
21
Automatic Level Control (ALC) Circuit (Main Unit)
22
Transmitter Mixer and Buffer Amplifier (RF-YGR Unit)
22
Power Amplifier
22
ALC and Power Limiter (IC-271 H)
22
Power Amplifier Cooling System (IC-271 H)
23
PLL (HPL) Unit
23
Reference Oscillator and lo Circuits
23
HPL Unit Block Diagram
23
Mixer Amplifier Circuit
24
Prescaler Circuit
24
Loop Filter
24
Sub-Loop Circuit
24
Mode and Frequency Step Circuits
25
CPU Port Allocations
25
CPU Memory Map
25
Auto Tuning Rate(Ts), Program Scan (Ps), MIC Up/Down Circuits
26
Input/Output Control IC Port Allocations
26
Matrix Circuit
27
Display and PLL Strobe
28
Display Data
29
Mode, Memo, VFO, Scan and Rit Displays
29
Scan Circuit
30
MIC Up/Down Circuit
30
N Data
31
Tone Generator
31
Filter Unit (IC-271 H)
31
RF Meter Detector, SWR Detector, Protector Circuits
32
CSS and DC-DC Units
32
CSS (Center Scanning Stop) Circuit
32
Display Unit
32
Display Unit Circuit
33
Power Supply Switching Circuit (Main Unit)
33
Transmit/Receive Switching Circuit (RF-YGR Unit)
33
Terminal Circuit Board (IC-271 H)
33
Mechanical Parts and Disassembly
34
Frame Disassembly (IC-271 A/E)
34
Frame Disassembly (IC-271 H)
36
Front Panel Disassembly
38
Front Sub-Chassis Connector Assembly
40
Main Board Connector Assembly (IC-271 A/E)
41
Logic/Pll Board Connector Assemblies (IC-271 A/E)
42
Logic/Pll Board Connector Assemblies (IC-271 H)
43
Rear Panel Connector Assembly (IC-271 A/E)
44
Rear Panel Connector Assembly (IC-271 H)
45
Rear Panel Parts Disassembly (IC-271 A/E)
46
Rear Panel Parts Disassembly (IC-271 H)
47
Maintenance and Adjustment
49
Preparation before Servicing
49
PLL Adjustment
50
Main Unit
51
HPL Unit
52
Transmitter Adjustment
53
Tone Unit
55
RF YGR Unit
58
PA Unit (IC-271 H)
59
Logic Unit
60
Receiver Adjustment
61
CSS Unit
62
RF-YGR Unit
64
VR Unit
64
Circuit Diagrams/Voltage Charts
65
EF Unit
65
Terminal Unit (IC-271 H)
81
Tone Unit (#02, 05)
82
Transistor Voltage Chart
83
IC Voltage Chart
84
Board Layouts (IC-271 H)
85
IC Specifications
94
Parts List
107
IC-271 A/E Schematic Diagram
128
IC-271 H Schematic Diagram
138

ICOM IC-271A Service Manual (71 pages)

Wideband Receiver

Brand: ICOM | Category: Receiver | Size: 29.25 MB

Icom IC-271A Instruction Manual (32 pages)

144MHz All Mode Transceiver

Brand: Icom | Category: Transceiver | Size: 7.62 MB

Icom Categories

Transceiver Receiver Repeater Radio Two-Way Radio

More Icom Manuals

Icom IC-271A Manuals

Icom IC-271A Maintenance Manual (148 pages)

Table of Contents

ICOM IC-271A Service Manual (71 pages)

Icom IC-271A Instruction Manual (32 pages)

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