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Channel ID Calculators for Type II Trunking Radio Systems

These programs takes as input a number representing the talk group displayed on a trunking receiver. The output is the base channel of that ID and a list of its various modes. It also does a simple check to see if the channel is a valid Indianapolis MECA channel ID. The program is usable with all normal Type II Trunking Radio Systems.

Trunkcalc2 - GTK+ 2.0

Made in Glade!

Features

Redhat 8 Package
TrunkCalc2 for Linux (requires GNOME 2)
C Source Code
TrunkCalc2 Glade2 project with C source

TrunkID - GTK+

Windows 98, Me, 2000, XP
Windows Executable (includes GTK 1.3)
Linux 2.2 (glibc 2.1) Executable
Linux 2.2 Executable (requires GTK 1.2 & glibc 2.1; e.g. Redhat/Mandrake 6.x)
C Source Code
Glade project with C source

Visual Basic

Windows 32-bit Executable
Windows 95, 98, NT, 2000 Executable (requires VB 5 Runtime, already on most systems)
Visual Basic Source Code
Visual Basic 5 project and source files

PHP

Base Channel:

PHP Source Code
PHP Source

Simple/Fuzzy Manual Calculation

For those without Boolean calculators, you can determine a valid base channel like such:

If the result is an Integer (e.g. 34.00, not 34.12) then you are on a channel operating in mode 0
baseChannelNumber / 16

Complex/Accurate Manual Calculation

For Motorola Type-II Trunked systems you can use the following Boolean equations to calculate channel information

% is the modulus operator, modulus is a Boolean math operator (Like +, -, /, *) which returns the current 'mode' of a multiplexed binary system. It is simply a special form of whole integer division; hence the % sign which looks like a funky / sign. In simple math 5 / 2 = 2.5 where 5 % 2 = 1 (4 / 2 remainder 1)

Channel Mode

channelMode = channelNumber % 16
2 = 4722 % 16
baseChannelNumber = channelNumber - (channelNumber % 16)
4720 = 4722 - 2

Scanning Note

  1. Indianapolis MECA System 1 & 2 normally only use modes 0, 2, 3, 7, 8
  2. Generally multiple modes are not used on any one channel. For example, 4720 wouldn't be activated while 4722 is in use.