DE
DANIELS
ELECTRONICS
VT-4B150 VHF Project 25 Digital Base Transmitter Instruction Manual
iii
TABLE OF CONTENTS
Page
1
GENERAL..................................................................................... 1-1
1.1 Introduction.............................................................................. 1-1
1.2 Manual Organization.................................................................... 1-1
1.3 VT-4B 136 - 174 MHz Transmitter Family Models ................................ 1-1
1.4 Performance Specifications ............................................................ 1-2
1.4.1 General................................................................................ 1-2
1.4.2 Audio Specifications................................................................. 1-3
1.4.3 Physical Specifications .............................................................. 1-3
2
THEORY OF OPERATION................................................................. 2-1
2.1 Transmitter Operation................................................................... 2-1
2.2 Transmitter Programming.............................................................. 2-1
2.2.1 Transmitter Wide Options........................................................... 2-2
2.2.1.1
Disable Front Panel Led.......................................................... 2-2
2.2.1.2
Secure Hardware Equipped...................................................... 2-2
2.2.1.3
Allow Emergency Transmissions ............................................... 2-2
2.2.1.4
Allow Radio Inhibit............................................................... 2-2
2.2.1.5
Allow Radio Check ............................................................... 2-2
2.2.1.6
Enable Status ...................................................................... 2-2
2.2.1.7
Frequency Band................................................................... 2-2
2.2.2 Channel Wide Settings .............................................................. 2-3
2.2.2.1
Frequency.......................................................................... 2-3
2.2.2.2
Voice/Signal Type................................................................. 2-3
2.2.2.3
Squelch Type ...................................................................... 2-3
2.2.2.4
CTCSS Tone ...................................................................... 2-3
2.2.2.5
Enable Reverse Burst............................................................. 2-3
2.2.2.6
DCS Code.......................................................................... 2-3
2.2.2.7
DCS Invert......................................................................... 2-4
2.2.2.8
Enable Turn Off Code ............................................................ 2-4
2.2.2.9
Transmitter Power ................................................................ 2-4
2.2.2.10
Channel Bandwidth ............................................................. 2-4
2.2.2.11
Deviation.......................................................................... 2-4
2.2.2.12
Time Out Timer .................................................................. 2-4
2.2.2.13
Channel Status ................................................................... 2-4
2.2.2.14
Transmitter Pre-emphasis....................................................... 2-4
2.2.2.15
NAC Transmitter Code ......................................................... 2-5
2.2.2.16
NAC Transmitter ................................................................ 2-5
2.3 Transmitter Programming using Motorola Radio Service Software .............. 2-5
2.4 Secure Communications................................................................ 2-6
2.5 Transmitter Assembly and Adjustment ............................................... 2-6
2.5.1 Controller Board Alignment ........................................................ 2-6
2.5.1.1
Reference Oscillator Adjustment ................................................ 2-6
