Table of Contents
4-ii
Theory of Operation
6.0
Receive Audio Circuits
............................................................................ 12
6.1
Squelch Detect .......................................................................................... 12
6.2
Audio Processing and Digital Volume Control ........................................... 13
6.3
Audio Amplification Speaker (+) Speaker (-) ............................................. 13
6.4
Handset Audio ........................................................................................... 14
6.5
Filtered Audio ............................................................................................ 14
6.6
Discriminator Audio (Unfiltered)................................................................. 14
6.7
Option Board Audio ................................................................................... 14
7.0
Receive Signalling Circuits
..................................................................... 15
7.1
Sub-audible Data Decoder (PL/DPL) ........................................................ 15
7.2
High Speed Data Decoder......................................................................... 15
7.3
Alert Tone Circuits ..................................................................................... 16
8.0
Receiver Front-End
.................................................................................. 17
8.1
Front-End Band-Pass Filter & Pre-Amplifier .............................................. 17
8.2
Mixer and Intermediate Frequency (IF) Section ........................................ 17
8.3
IF IC (U5201) ............................................................................................. 18
9.0
Power AmpliÞer (PA) 5-25W.
................................................................... 18
9.1
Power Controlled Stage............................................................................. 18
9.2
PA Stages.................................................................................................. 19
9.3
Directional Coupler .................................................................................... 19
9.4
Antenna Switch.......................................................................................... 19
9.5
Harmonic Filter .......................................................................................... 20
9.6
Power Control ............................................................................................ 20
10.0
Frequency Synthesis
............................................................................... 21
10.1
Reference Oscillator .................................................................................. 21
10.2
Fractional-N Synthesizer (U7501) ............................................................. 21
10.3
Voltage Controlled Oscillator (VCO) .......................................................... 22
10.4
Synthesizer Operation ............................................................................... 22
11.0
Receiver Front-End
.................................................................................. 24
11.1
Front-End Band-Pass Filter and Pre-Amplifier .......................................... 24
11.2
Mixer and Intermediate Frequency (IF) Section ........................................ 24
11.3
IF IC (U5201) ............................................................................................. 25
http://www.myradio168.net
Содержание GM950E
Страница 2: ...ii h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 4: ...Cautions and Warnings iv h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 6: ...Cautions and Warnings vi h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 8: ...Contents viii Service Manual h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 10: ...Table of Contents 1 ii Introduction h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 14: ...GM950E GM950i Technical SpeciÞcation 1 4 Introduction h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 16: ...Table of Contents 2 ii Model Chart and Accessories h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 20: ...Table of Contents 3 ii Maintenance h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 38: ...Table of Contents 4 iv Theory of Operation h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 87: ...UHF Main Board Supply Voltage 5 24 Schematic Diagrams and Parts Lists h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 90: ...5 28 Schematic Diagrams and Parts Lists h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 96: ...UHF Main Board Synthesizer 5 36 Schematic Diagrams and Parts Lists h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 119: ...VHF GM950E Main Board Controller 5 68 Schematic Diagrams and Parts Lists h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 122: ...VHF Main Board Supply Voltage 5 72 Schematic Diagrams and Parts Lists h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 125: ...5 76 Schematic Diagrams and Parts Lists h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 131: ...VHF Main Board Synthesizer 5 84 Schematic Diagrams and Parts Lists h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 144: ...5 102 Schematic Diagrams and Parts Lists h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 148: ...Main Board Control Head P 5 108 Schematic Diagrams and Parts Lists h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 150: ...Table of Contents 6 ii 216 246MHz Specific Information h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 152: ...Table of Contents 6 1 ii Model Chart and Technical Specifications h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 156: ...Technical Specification 6 1 4 Model Chart and Technical Specifications h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 158: ...Table of Contents 6 2 ii Radio Tuning Procedure h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 194: ...Table of Contents 6 4 ii PCB Schematic Diagrams and Parts Lists h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 216: ...Table of Contents A ii PL CTCSS Codes h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 218: ...Self Quieting Frequencies A 2 PL CTCSS Codes h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 220: ...Table of Contents B ii External Device Connectors h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 224: ...Microphone Connector B 4 External Device Connectors h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 226: ...Table of Contents C ii Radio Conversion h t t p w w w m y r a d i o 1 6 8 n e t ...
Страница 228: ...How to alter the radio for Base Station Operation C 2 Radio Conversion h t t p w w w m y r a d i o 1 6 8 n e t ...