The ability to be able to hear what is going on with your local repeater is crucial for proper operation. Repeater users must be able to hear each other when using the same repeater. With analog radio, if 2 users transmit at the same time, you may hear both users or you may hear distorted audio from only one user. With digital radio, the audio may sound garbled or it may not even pass. But with DMR, you may not hear everything on that time slot unless the radio is programmed to do so. Lets look at a few ways this may be accomplished

Promiscuous Mode

The term “Promiscuous Mode” has been tossed around in the DMR community for some time. Promiscuous mode simply means that the radio will allow any talk group traffic to be heard, even if it is not the the talk group that the radio is set on at that time. Most radios that offer this will only hear one time slot at a time though. So if you have your radio set to listen on talk group 31285 on time slot 2, you would only hear the other talk groups that are on time slot 2. Promiscuous mode will usually work independent of whatever channel you are on. So if you change channels on the radio, it will still pass audio for any talk group that is active on the same time slot that the channel is set for. Promiscuous mode is not available on all DMR radios. For example, the earlier versions of the TYT MD-380 had to be flashed with “hacked” firmware in order to have this ability. Later versions including the dual band MD-UV380 had the option, although it was not called Promiscuous Mode. Instead you would go into the menu or with the software, and turn off Group Call Match and Private Call Match.

Digital Monitor

Some radios, such as the Connect Systems CS-800D have an option called “Digital Monitor”. This feature works similar to promiscuous mode, but has to be turned on again if the channel is changed. Early versions of the firmware for the CS-800D allowed the radio to only hear traffic for the time slot that the selected channel was set to. Now you should be able to hear both time slots regardless of channel with the latest firmware.

Receive Groups

Receive groups allow you to hear traffic on any talk group that is set in that receive group, regardless of what channel that radio is on. For instance, say your local repeater has 3128, 31285, and 31471 static on time slot 1, and you want to be able to hear any of those talk groups when you are using that repeater on the same time slot, then you would set up a Receive Group with those talk groups in them. In most radios you would also have to apply that receive group to each channel as well. many time you can also have multiple receive groups, which can be handy as some repeater settings vary from one to the other.

Final thought

Options vary from radio to radio. Features that one brand has may not be available in another brand, or the naming of the features may be different. As stated before it is important to utilize the features mentioned above so that the systems works smoothly and all users have a good experience. If you have difficulty understanding the features on a radio, research the radio, ask the question and educate yourself on the radio(s) you have.