This may seem like a simple topic however it’s slightly different with DMR.
These are usually 1-2 second (or a few seconds longer) gaps between transmissions to allow other users the time to join a qso or put out a call for someone. Usually this is done by calling out your call sign or saying “break”. It’s standard practice to leave these gaps especially when waiting for someone join the qso and more so when repeaters are linked as is the case with DMR as you never know who is out there waiting for a space.
Non- Standard Pause
Due to DMR having multiple talk groups on a time slot, the standard pause of around 2 seconds can be insufficient for the network/repeater to release the slot long enough to permit other users to key up another talk group. For instance, you have a group of users on TG803 between GB7WL, GB7NS and GB7SE. Now a user on another repeater that also has TG803 wants to have a chat on TG80 but as TG803 is in use he can’t get a gap to key up TG80.
This is where a “non-standard” pause is required – it’s a longer pause that allows the carrier to drop and other users to key up other talk groups on their repeaters. If someone finishes a transmission on TG803 and I key up TG80, either I will get a channel busy tone or depending on how my code plug is setup, I will come out on TG803 as the carrier is still active. In simple terms, when you are listening to a qso, on your display you will see “TG803 SE Link” or whatever the talk group is named as within your contacts. You would only be able to use TG80 when that display goes back to your repeater entry such as “GB7EK TG80 UK UA 1”.
In theory this should only affect users when others are on the likes of the calling channels (long qso’s are still taking place on these talk groups), special links and slot 2 (local and the home region). It used to be the case that if you left a pause that was too long, there was a danger that another wide-area talkgroup could interupt your conversation. For this reason, so called ‘hold-off timers’ were introduced on the user activated groups. These effectively lock out other talkgroups for a short period and enable longer pauses between transmissions.
TG9 (slot 2) and the user activated talk groups would be the main talk groups that a user may be trying to access. Once successful access has be achieved, the hold-off timer will lessen the chance of you loosing the slot (refer to the “User Activated” menu).
As the UK Wide User Activated channels are quite popular during the morning and afternoon commuting period, some users would have had to wait for a longer gap in transmission (non-standard pause) in order to key up the talk group. This is an issue many have had thus I thought it necessary to add this section to the webpage.
As most users leave a short pause and many that know of this issue do leave longer pauses, the only other way around it is to join into the active qso and politely request a longer pause as “you need the carrier to drop” so that you can access another talk group on your repeater. This is an unfortunate feature but then users need to work together to make this work – best it’s done in a polite manner and advise what you need and why you need it so that the other users understand – “Good afternoon all, this is G6xxx – please could you leave a longer pause of around 5 seconds after this transmission as I would like to access TG80 but i need the carrier to drop”. Eventually users will get used to this issue and it will become quicker and easier to resolve.