User's Manual

ST-3118C SM R 1.1 SMARTRUNK SYSTEMS, INC.
2
Contents
1. Specifications: ............................................................................................................................... 5
2. ST-3118 EXPLODED VIEW .............................................................................................................. 6
3. ST-3118C SIMPLIFIED DIAGRAM ................................................................................................... 7
4. - ST-3118 RF DESCRIPTION ................................................................................................................ 8
4.1. Circuit Configuration ................................................................................................................. 8
4.2. Receiver System ........................................................................................................................ 8
4.2.1. Front-end RF Receiver ........................................................................................................... 8
4.2.2. ANALOG Audio Processing .................................................................................................... 8
4.2.3. Virtual Squelch Circuit ........................................................................................................... 8
4.2.4. Virtual VOLUME CONTROL .................................................................................................... 9
4.2.5. Sub audio signaling ............................................................................................................... 9
4.2.6. ANALOG AUDIBLE SIGNALING ............................................................................................... 9
4.2.7. DIGITAL AUDIO PROCESSING ................................................................................................ 9
4.3. Transmitter System ................................................................................................................. 10
4.3.1. ANALOG TX SIGNAL ............................................................................................................. 10
4.3.2. DIGITAL TX AUDIO: .............................................................................................................. 10
4.3.3. Drive and Final Amplifier Stages ......................................................................................... 11
4.3.4. Automatic Transmit Power Control .................................................................................... 11
5. ST-3118 ALIGNMENT ................................................................................................................... 12
5.1. Introduction ............................................................................................................................ 12
5.2. ALIGNMENT:............................................................................................................................ 12
5.3. Required Test Equipment ....................................................................................................... 13
5.4. Alignment Procedure .............................................................................................................. 13
5.4.1. GENERAL ALIGNMENT CONSIDERATIONS: .......................................................................... 13
5.5. MAIN RADIO ALIGNMENT ....................................................................................................... 14
5.6. TRANSMITTER ALIGNMENT: ................................................................................................... 14
5.6.1. Main Clock alignment: ........................................................................................................ 15
5.6.2. Transmit Power alignment: ................................................................................................. 15