TAC talkgroups are a specialized set of talkgroups that provides a more
efficient use of repeaters and networking. The technique enables 2 or more hams (on 2 or more repeaters)
busying out scores of repeaters and/or multiple IPSC networks.
Consider it a routing method somewhat similar to
STARnet, a PSTN trunk line or Tactical or a "go-to,
on-demand channel" to be used after making contact on
a wide area talkgroup such as PNW 1 or 2, WA 1 or 2, text message or by way of a schedule.
It is not a calling talkgroup per se but a destination talkgroup in most
TAC's are destination talkgroups by design though some are now used for full
time QSO such as 310. But consider it
like an old-fashioned party-line telephone, if you don't pick-up the handset
(PTT), you do not hear it, you are not heard nor are you impacted by the conversation and
likely more importantly, TAC does not load
your IPSC networked timeslot. It is completely passive or benign to
your repeater or IPSC network unless or until you hit the pickle (PTT).
This approach puts you or your local users in complete control of your
local repeater's timeslot.
All PNW DMR managers/repeaters/networks now have the TAC series talkgroups enabled and
available for use. But not all TAC's are available everywhere and some
have very specific purposes. Consult the s:
talkgroup detail and the
Matrix for specific purpose and
Why call them TAC's? TAC is short for tactical, a term used in
law enforcement and other public service agencies for unit to unit
operations or communication so that the main dispatch frequency is not tied
up for lengthy conversations. The idea is the same for DMR; that is, to provide
talkgroups that do not tie up the wide area talkgroups which have many
repeaters connected. This approach enables a few hams to chat without
that negative impact to the main talkgroups while using the fewest
possible repeaters to make the conversation possible.
Initial implementation will be via c-Bridge CC's. DCI has
added a second c-Bridge to act as a
part of the "Buffer Bridge BackBone" project, also known as
QB. We then enabled CPM's for
these QB c-Bridges as well as for the X Box 15's, 30's &
50's if desired. c-Bridge admins and repeater owners may wish to
explore the value of switching from your CC to a
CPM on the
The c-Bridge development team has a different and far more elegant approach on the drawing
board to reduce the number of impacted repeaters for Point-to-Point routing but the timeline is such that they have suggested that I go forward
with this approach for now. Certainly it would be a simple process to
"unwind" TAC if/when their TG routing native to the c-Bridge, is rolled out.
Both projects are in the interest of the entire ham community to explore
a more efficient and dynamic use of repeater air and timeslot time.
The TAC talkgroup project was was created on February 2,
2014 after first proposed on January 21st. TAC 311, the first
expansion TG modeled on the innovation of TAC 310, began operation on NATS on
8-16-2014. TAC 1 created also on NATS is the first international, any
language TAC talkgroup.