In the early days of DMR, mostly in Europe, DMR repeaters used the DMR+ network. This network is reflector based, much like how D-STAR works.
Before getting very far into the discussion, it is important to know there are talkgroups associated with each of the reflectors. The only advantage to a reflector is it’s dynamic nature…being able to use them without programming channels. However, several of the modern DMR radios allow you to manually enter group call IDs, this negates the need for reflectors.
When using a reflector, think about a hub with multiple repeaters (or hotspots) connected. Each repeater sends RF traffic to the reflector and the reflector sends that traffic to all other connected repeaters. A repeater can be connected to only one reflector at a time and anyone using that repeater (on TG9) will be communicating through the same reflector.
You can talk through the connected reflector using Talkgroup 9 on timeslot 2. When no reflector is connected, TG9 operates like a local talkgroup.
Connecting a reflector is fairly easy. Tune your radio to TG9, in many code plugs this will be labeled “Ref” or “Reflector”. You will then issue a private call to one of the reflector numbers. Reflectors are numbered 4001- 4999. If there are reflectors you plan to use frequently, you can add them to your contact list. Most radios will allow you to go into contacts and manual dial a contact.
There are also two special id’s on either side of the reflector range that must be sent as private calls:
- 4000 – Issuing a private call to 4000 will disconnect a reflector
- 5000 – Issuing a private call to 5000 will tell you which reflector is connector (or none)
As mentioned above, all reflectors have an associated talkgroup. You can view the list at http://registry.dstar.su/dmr/reflectors.php. This list is not very user friendly but you will find entries like this:
4001@TG26312 Berlin-Brandenburg@1@1234 4002@TG26321 Hamburg@1@1234 4003@TG26323 Elbe-Weser@1@1234 4004@TG26361 Hessen@1@1234
Use the “@” to separate fields as follows:
- Reflector number
- The associated talkgroup and description
You can also use the BrandMeister web site to see if a reflector is connected. You can view a repeater info page (https://brandmeister.network/?page=repeater&id=110614, replace the ID with your local repeater) and look at the “Slot details” section. This will show you if a reflector is connected, and the reflector number. This works for hotspots as well.
If you have a repeater or hotspot there is some configuration related to reflectors. You can set a default reflector and a timeout to return to the default reflector. You can also manually set or clear a reflector. This is done on the settings page for your repeater or reflector.
The defaults give you no automatic reflector, and not timeout to return to a specific reflector.
- Active Reflector – set or clear a reflector. Use “0” to clear a connected reflector
- Default Reflector – Set this to a reflector number to be always connected, or “0” to be not connected.
- Reflector Timeout – The number of seconds of inactivity before returning to the Default Reflector.
I recommend setting the default to zero and the timeout to a reasonable value (5 minutes). This way, if someone leaves your repeater connected to a busy talkgroup, it will timeout and disconnect.