DMR Learning Series: Talk Groups

What is a talk group and how do I use it?

Talk Group Basics

Talk groups are a way of separating individual groups of people on the same physical channel, and the concept has some similarities to PL or DPL on analog, but they are not exactly the same.  Let’s take a look at an example business use for multiple talk groups.

I run a hotel, and there are several departments in the hotel that need to communicate via radio: Maintenance, maid service, management, and security.  The most basic way to allow them to communicate would be with four separate analog channels or repeaters.  Maintenance would be channel 1, maid service channel 2, management channel 3, and security channel 4.  This is highly inefficient, because there’s a good chance that these channels would sit idle most of the time.

Let’s introduce talk groups into this scenario and put all of the radios on the same frequency.  Maintenance is now on talk group 1, maid service talk group 2, management talk group 3, and security talk group 4.  The individual radios are configured to only un-mute themselves for their respective talk groups.  I now pick up a security radio and transmit, and even though all of the radios in my system are on the same frequency, only the radios carried by security officers will un-mute.  I won’t have to bother the maintenance people with radio traffic they don’t care about. Here’s a simple diagram of how this works:

 

 

 

This works the same way for repeaters.  If I talk into the repeater on the security talk group, it will retransmit that on its output frequency, and only radios on that frequency that are configured to receive that talk group will un-mute.

 

How Talk Groups Work on Ham Repeaters

In amateur radio, talk groups tend to be divided by region or purpose.  For example, the Worldwide calling talk group is 1.  The Midwest calling talk group is 3169.  The local talk group on many repeaters is 9. Unfortunately, talk group IDs can vary between repeaters on different networks, so be sure to consult your repeater owner for talk group information.  For example, here is the talk group listing for the N8NOD repeater east of Cleveland, Ohio.

 

Programming Talk Groups Into Your Radio

To add a talk group to your radio, you will first need to add it as a “contact.”  Enter the name of the group – you can call it whatever you want, but consistency is helpful, so try to use the same name as is listed. The contact type will be “group call.”

  • MD380/390 CPS: Digital Contacts, add.
  • CS750 CPS: Conventional, DMR Services, Contact, add.
  • MotoTRBO CPS:
    • Under Contacts, right-click “Digital”
    • Select Add, Group Call

Once you have added the contact for the group, you will need to set up a receive group list that contains that talk group.  Then, set up a channel that transmits to that talk group by default and uses the receive group list that you just set up.

Stay tuned for more articles in the series that discuss receive group lists and channels.

Questions or comments? Did I miss something? Leave a comment below!

DMR Learning Series: Talk Groups
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