Understanding NXDN Talkgroups

[Paul Toth-NB9X]

Since we have a number of new NXDN users on the list since I first posted this information, I thought it would be useful to share it again.  You may want to print this email for future reference/

 

What is a NXDN Talkgroup and a TGID?  A Talkgroup is a logical mechanism designed to allow operators with a common interest to communicate with each other without opening the squelch on every radio on the network.  In commercial applications, Talkgroups may logically organize radio-equipped employee by Department or Task Assignment.  That is certainly possible in Amateur Radio, too.  For example, in a post-disaster application, Hams provided Shelter Operations support might be assigned their own Talkgroup (TGID) and use SELective squelch so as to only transmit and receive voice and message traffic of specific interest to them.

 

For normal day to day communications, here are the Talkgroups and their IDs used most often here in West Central Florida:

• TG 1   If you want to limit your communications to a single repeater, use thiis Talkgroup.  The NXCore reflector that serves as the clue for the TampaBay Area NXDN Repeaters will keep your traffic localized to the repeater you are using.
• TG 1200   This Talkgroup ID allows you to communicate through the four NXN repeaters currently connected in the TampaBay area.  For example, if you are in Pasco County and you wish to hold a QSO with another operator in Manatee County, use this TGID.  The TampaBay Area NXDN Net on Wednesdsy evening at 8:00 PM uses TG 1200.
• TG 9000   This Talkgroup will connect you with Hams in New England.  TG 9000 is based in Connecticut but also covers part of MA, NH and RI.
• TG 25000  This TGID will also connect you with Hams in Massachusetts and the NE United States
• TG 65000   This is the NXDN Worldwide Talkgroup.  It was created with a goal of linking ALL NXDN users and repeaters throughout North America and elsewhere together.  TG 65000 is still a work in progress, primarily because of differences in how ICOM and Kenwood repeaters port critical data for linking.  The developers of the NXCore reflector software are working to overcome those differences allowing a Ham going through an ICOM repeater to link with another Ham using a Kenwood device.

Once the ICOM-Kenwood linking issues have been resolved, it is likely TG 1200 will become a statewide Talkgroup in Florida.  That means your QSO here will be heard in Orlando Tallahasse and other areas where Kenwood repeaters currently serve the Ham NXDN community. 

 

There are two TGIDs that are considered by both ICOM and Kenwood as GLOBAL WILDCARDS.  TG 0 and TG 65535 are designated for the ALL CALL function.  That is, if you are trying to reach EVERYONE at the sam time, no matter which TGID they are monitoring, these two TGIDs will accomplish that.  I think you can see the potential ramifications of using TG 0 or TG 65535.

 

One final note.  If you want to hear ALL TRAFFIC, no matter which Talkgroup you have programmed into a Memory Channel, use RAN squelch.  This setting will open your radio anytime there is traffic on the frequency you are monitoring, no matter which TGID is being transmitted.  Just remember, if the traffic on the frequency is using a TGID that is different than the one you have programmed, you will need to determine the active TGID in order to participate in the QSO.

 

More on Talkgroups Wednesday evening at 8:00 PM EST during the TampaBay Area NXDN Net.

 

73 de Paul-NB9X