Master Control Talkgroups


Master Control Talkgroups or MCT's are special talkgroups (group calls) that will override the default or normal settings and timers of most or possibly all talkgroups on a given manager's timeslot.  MCT's provide a semiautomatic method to keep other talkgroups from barging into an active conversation.  They may control 1 timeslot or both timeslots. See the PowerPoint PDF.

TIP:  If you wish to turn off a TS 2 talkgroup(s), you do not need to wait for an opening, just Ker-Chunk as you are TX'ing onto TS1, not nearly as busy as TS 2 (if TS 1 is busy, you will get bonked of course).  Sort your zones so that the MCT's are in the middle to cut down on the thumbing or place MCT off in multiple places in your zone (beginning, middle and end; 3 times)

Up to 4 channels may be needed to control both timeslots to make use of the power of the MCT method of talkgroup control.  If your radio is limited to 16 channels per zone, you may wish to add a second or third zone for a particular repeater to make room for the MCT's as well as the additional talkgroups that are supported on the PNW repeater managers (the c-Bridge).

NOTE: Want to keep this simple?  Local 1 and Local 2 will also have the same "control off" capabilities but typically for a shorter off time (5 minutes) and only on their own timeslots. 

Manager IPSC Network Status / Notes TS 1 On TS 1 Off TS2 On TS2 Off
12   23-24 Seattle - Cougar All hold-offs and MCT's 16771231 16770231 16771242 16770242
13   25-26 Spokane - Lookout Pt All hold-offs and MCT's 16771251 16770251 16771262 16770262
14   27-28 Tacoma - Baldi Mtn Coded 16771271 16770271 16771282 16770282
20   39-40 Richland - Rattlesnake Coded  16771391 16770391 16771402 16770402
22  43-44 Oregon Mobile Coded 16771431 16770431 Use TS1 Use TS1
24   47-48 Bellingham - Lookout VHF Coded 16771471 16770471 16771482 16770482
26   51-52 Oso Frailey Coded 16771511 16770511 16771522 16770522
30   59-60 Capitol - Olympia Coded 16771591 16770591 16771602 16770602
31   61-62 Oregon South Coded 16771611 16770611 16771622 16770622
32   63-64 Mt Hood OR Coded 16771631 16770631 Use TS1 Use TS1
33   65-66 Hebo - Mt Hebo OR Coded 16771651 16770651 Use TS1 Use TS1
34   67-68 GAFS Coded 16771671 16770671 Use TS1 Use TS1
35   69-70 Bellingham - Lookout UHF Coded 16771691 16770691 16771702 16770702
36   71-72 Kelso - Rainier Hill Coded 16771711 16770711 Use TS1 Use TS1
37   73-74 Oregon - House Coded 16771751 16770751 16771742 16770742
38   75-76 Bremerton - Gold Mtn Coded 16771771 16770771 16771762 16770762
39   77-78 Boistfort - Baw Faw Coded 16771771 16770771 16771782 16770782
40   79-80 Ellens - Moses - Wen Coded 16771791 16770791 16771802 16770802
41   81-82     16771811 16770811 16771822 16770822
43   85-86 Yakima Coded 16771851 16770851 16771862 16770862
48   95-96 Coeur d'Alene - Blossom Coded 16771951 16770951 16771962 16770962
NOTE:  ALL MCT's must TX on timeslot 1, do not TX on timeslot 2, even though the MCT may control timeslot 2 talkgroups
Local 1 & 2 can be used as shorter MCT Off controls, so the additional MCT talkgroups may not needed in all user zones

How it Works

These talkgroups are special in that they are not used for voice traffic but as a control method (much like DTMF) to override the standard or default talkgroup timers and states associated with each talkgroup.  Newly created c-Bridge managers (IPSC network repeater groups) will be based on this Master Control Talkgroup (MCT) concept while older managers will keep their hold-off timers as the primary method of talkgroup manipulation.

  • Suggested:  Use One Touch buttons or place Local 1 & 2 channels either in position 1 & 2 or 15 & 16 on HT's for easy and frequent access.  One touch is best for MCT on's while MCT off's are best used in position 16 (or 15/16) on a HT for quick kerchunks.  You may wish to set the One Touch menu timer to 30's or so.

  • New PNW managers will have 2 set of two MCT's; "Master Off" and "Master On" for one or both timeslots.  Some older managers have only 1 set of 2 MCT's for control of both timeslots (see chart above)

  • Each MCT On will turn on some or all networked TG's on one or both timeslots (typically 55 or 59 minutes).  On's will seldom be used

  • Each MCT Off will turn off all networked TG's on one or both timeslots (typically 15 or 29 minutes).  Off's (or Local) will be used extensively

  • Local 1 & 2 will also act as MCT Off's but with shorter hold-off timers (typically 5 minutes)

  • Some PTT talkgroups may be turned on via MCT; programming is up to repeater owner on which if any.  These variations may or may not be documented, contact the repeater owner for more information.

How it works for a PNW Local Repeater User

Normally a user should turn off all talkgroups prior to making a call via MCT Off or Local.  Then a kerchunk on the talkgroup of choice will turn this one talkgroup back on.  Once done with a conversation, the user can optionally kerchunk the main TG back on.  If they don't do this, the default state will return within 15-29 minutes, a time span determined by the network manager and/or repeater owners.  This time span is selected to try to match the typical length of a conversation.  If a conversation is longer than the timer, then the user should re-kerchunk the Master Off or you will roll the dice on loosing the timeslot to another talkgroup that may go active during an extended conversation.  This is the MCT method described in it's simplest form.

The stock Master On timer will turn on all talkgroups, including those that are normally full time by default just incase they were turned off.  This likely will be infrequently used while the MCT Off command will be very commonplace. The network manager and/or the repeater owners may select other options such all talkgroups on or some of the PTT talkgroups turned on.  This is all determined before the manager is coded.  So some or all of the PTT talkgroups could be turned on as some sort of monitoring situation.

If the user doesn't Master Off first, then any talkgroup that is fulltime is capable for grabbing the timeslot and preempting the current conversation.  The user would then need to time a Master Off kerchunk between the current talkers Tx cycle.  Then kerchunk their talkgroup back on.  If you don't mind losing your active conversation, then no need to use the MCT's.

It is suggested that users with HT's, program the Master On and Master off MCT's in positions 15 and 16 (and 13/14 if both timeslots are used in one zone).  This will make it easy to spin the dial to the top to quickly turn off the talkgroups.  Mobiles with more channels may wish to have more than 1 MCT set in the zone to simply getting to them for a kerchunk.

Another user radio programming option is to program up the MCT via dedicated front panel keys if your radio supports it so there is no need to have the MCT's using 2 or 4 channel slots in your zone.  Pushing outside the box, the MCT Off TG's could be used a Local only talkgroup on either slot, increasing the versatility of that channel slot.


Let's say that Washington 2, PNW 2 and DCI 2 are all on full time (by default), this being typical for most PNW managers.  Now comes a local user who wants to talk on TAC 310 (PTT by default).  The user has two choices, key up on TAC 310 to turn it on and then begin a conversation or kerchunking "MCT 2 Off" then switching to TAC 310. 

If the local user skips the "MCT 2 Off" step, everything can still work fine but those three full time talkgroups could go busy at any time and capture the timeslot thereby taking TAC 310 away from the active local user.  This effectively ends that local users conversation when other networked talkgroups are enabled but idling.

To keep from having the rug pulled out from under the local user (another talkgroup barging in), the user should turn off all talkgroups by kerchunking the "MCT 2 Off" talkgroup.  This provides 15 or 29 minutes (typically) of "quiet time" for a conversation.

At the end of the local user's conversation, the MCT 2 On talkgroup could be kerchunked to turn the timeslot's talkgroups back on.  If done though, it will turn on all timeslot 2 talkgroups, which may not be what you really want done.  So you could kerchunk the main TS 2 talkgroup back on, PNW 2 for example or just simply wait for the talkgroups to pop back on when the 15 minute timer expires.

So while MCT's are optional, they play an important role in for local users who wish to engage in a conversation.


  • Simple understanding to our local users on how the system works
  • Either talkgroups are On or Off
  • Can be called up via One Touch front panel programming via TRBO HT's and likely other makes as well
  • Fewer competing timer interactions to confuse users
  • Can be used to monitor nets (passively) without other talkgroup interruptions
  • c-Bridge admin time is minimized by a factor of up to 16 times simply to program a new manager
  • Local 1 & 2 will also act as MCT Off's but can have shorter hold-off timers of 5-15 minutes typically
  • Some c-Bridge groups are already using some form of MCT already. 
  • This admin has used MCT's for years on his local repeater managers and uses them daily


  • Less intelligent control dynamically during and between conversations
  • User should know and remember to initiate the sequence before beginning a conversation
  • May require the use of and space for the additional 1, 2 or 4 more talkgroups for dedicated channel space in zones
  • It is a new approach and harder for existing users to embrace change

While some "automation" is lost as are 1 or 2 channels per timeslot in a subscriber radio zone (suggest using One Touch buttons), this is a huge benefit to the admin who must code in up to all 37 timeslot 2 hold-offs for each of the talkgroups on the timeslot.  At the low end, 15 talkgroups on 1 manager can be 225 hold off timers or up to 1370 timers at the high end.  MCT's require only 1 timer per talkgroup or 15 additional line entries for a minimal timeslot.  Local 1 and Local 2 will add another hold-off timer entry but still well short of the upper end of 1300 plus currently.

In practice, there will likely a dual use of Locals as well as a combination of hold off timers for the full time talkgroups added to supplement the MCT's to insure a better experience by the local repeater users.  But at this point, a new manager with 15 TG's could be created and be useable in about an hour, far less than the 6-8 hours entering all the possible hold off timer combinations.


Revised: 10/21/2018 08:45