Brandmeister Dynamic Talk Groups
repeaters use dynamic Talk Groups (TG). These TGs only send DMR
network traffic to the repeater when a local repeater user keys up a
particular TG. The TG network traffic will be sent to the repeater
for a period of 15 minutes after the most recent key up by the local
to the nature of these dynamic TGs, specific procedures must be used
when keying up and using a TG. If done improperly several different
issues can occur:
local user keying up a TG can isolate another local user from the TG
he was using.
local user can key up a TG and disrupt an existing conversation on
local user can key up multiple simultaneous TGs on the same time
slot which can create TG chaos.
Before Keying Up a TG
keying up a TG, monitor the radio’s Channel Busy LED for at least a
minute. If the LED doesn’t light then both time slots are idle. Key
up your desired TG. Then listen for at least a minute before
transmitting to determine if the TG is busy. The reason for listening
is that, if a remote TG user is transmitting when you keyed up the
TG, you will not hear his audio nor will the Channel Busy LED light.
You will hear audio, and the Channel Busy LED will light, when the
next remote user begins transmitting.
the Channel Busy LED is on, or flashes on and off, then one or both
of the time slots are busy. To determine if your desired time slot is
idle or busy, wait until the Channel Busy LED is on and then key up
your TG. If a Busy Tone results, then your desired time slot is busy.
Do not key up again until the Channel Busy LED has been off for at
least a minute indicating that the time slot is now idle. The Channel
Busy LED will turn off and then back on between long conversation
keying up while the Channel Busy LED is on results in a Connect
Confirmation Tone, then your time slot is idle and your TG has been
activated. As mentioned above, listen before transmitting.
initially keying up a TG, give your callsign, your location, and the
TG. For example, “This is W6OAV in Denver on World Wide”. This
allows stations scanning to know who you are, where you are and what
TG you just keyed up.
wide area TGs, such as USA, WW, NA, etc should be used as a calling
TGs. Make your call on these TGs, and then arrange to change to a TAC
TG, such as 310, 311, and 312. Make sure that these TGs are clear
before you start talking on one of the TAC’s. Asking “Is this
talk group in use?” is a good way to start the conversation.
with analog repeaters, you must ID. Unlike Fusion and D Star
protocols, your callsign is not transmitted. Only your DMR ID is
transmitted across the network.
prolonged contacts so as to leave air time for other operators. When
you have a TG active you’re denying access for others to the Time
Slot and to the many available TGs.
of long delays introduced by digitally encoding, network routing, and
digitally decoding of DMR signals, communications delays are
inherent. You should wait a minimum of 3 seconds after a transmission
stops before keying up to accommodate breaking traffic. Then wait a
second after receiving the Confirmation Tone before speaking. This
allows the repeater and radio to complete syncing.
DMR-ID of a station appearing on the TG may be displayed momentarily
on your radio. This can occur when a station momentarily keys their
transmitter to switch TGs on a repeater or hotspot. This is not
necessarily an indication that the station wishes to be called. The
station may only wish to monitor the TG. Wait to see if the station
IDs indicating his intentions.
not engage in “TG Hopping”, a process where a station keys up a
TG, listens for a short period of time, then keys up another TG,
listens for short period of time and then repeats the same process
with another TG.
Do not key up another
TG before using the DMR Disconnect TG (4000) to release the active
TG. Remember, a dynamic TG will stay active for 15 minutes after the
last key up. We don’t want TG chaos!
summary, be courteous and have fun chatting with ham all over the