[TrunkCom] Connect Tone?

[Rich Carlson, N9JIG]

At 1:42 PM -0500 1/16/02, Jerry Kacprzycki wrote:
>In reference to 800 MHz, what is a Connect Tone?
>

Connect tones are somewhat similar to PL tones in form and function. 
They are subaudible tones of around 100 Hz. (There are 8 different 
tones above and below 100 Hz.) that are part of the requirements for 
access to a Motorola trunked system. When programming a mobile or 
portable subscriber unit for a system you need to have the correct 
connect tone as well as several other items.

Other than that there is little need for the connect tone information 
as relating to monitoring a system unless you are using Motorola 
radios to do so. Trunktrackers (BC780 etc.) do not need the Connect 
Tone, and in fact have no way of utilizing it.

Several software packages, like Trunker and Treport, will report the 
decoded connect tone. It is one more item that can be used to verify 
the control data belongs to a specific system, just like a PL tone 
can be used to verify the user on a conventional channel.

I have noticed that a couple of EDACS systems around me will display 
a PL of 74.4 Hz when monitoring the input frequencies of a system. 
Someone told me that they use 74.0 Hz. in a similar fashion as 
Motorola's Connect tone. Since this is within the tolerance of my 
inexpensive PL decoder it will display often. Whether it is required 
for access on an EDACS system I wouldn't know since I have no radios 
(or need for one) that will transmit on an EDACS system.


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