--By Jay Farlow, W9LW

Part Four of this blog series explained how to scan channels on the DM-32UV. Channel scanning is particularly useful to monitor multiple FM (analog) or DMR (digital) repeaters or combinations both. If, however, you only want to monitor all talk groups on a single DMR repeater, there’s a better way.

Programming the Baofeng DM-32UV Part One: Preparations
Programming the Baofeng DM-32UV Part Two: Entering Data for DMR
Programming The Baofeng DM-32UV Part Three: Cover FM (analog) Frequencies
Programming the Baofeng DM-32UV Part Four: Channel Scanning

The DM-32UV has a setting that allows a single DMR channel to receive any talk group on that channel’s time slot, regardless of what talk group the channel is set to. The DM-32UV customer programming software (CPS) calls the setting for this feature “Group Call Match.” By default, it is enabled, which means that the radio will receive only the talk group that you selected for the current channel. Disabling “Group Call Match” allows the radio to receive talk groups that are different than the talk group associated with the current channel. Some users refer to this capability as “promiscuous mode” or “digital monitor.”

To disable Group Call Match and thus enable promiscuous mode, click on “Option Feature” in the menu tree at the left side of the CPS. An Optional Features dialog box will open. Click the Digital tab. At the bottom of a column of check boxes, uncheck “Group Call Match.” See Figure 1, below.

After you save this new version of your codeplug to your PC and then write it to your radio, every DMR channel in your radio will receive any talk group that’s on the same RF frequency and time slot as the channel, regardless of what talk group the channel is configured for.

Repeaters transmit on two time slots but the DM-32UV provides no way to monitor more than one time slot per channel. The easiest way to monitor every talk group a repeater transmits after disabling Group Call Match is with the radio’s dual watch feature. Set VFO A to a channel that’s configured for one time slot and set VFO B for a channel that’s configured for the other time slot. The radio will then receive a transmission on any talk group on the time slot that becomes active first.

Warning: Disabling Group Call Match facilitates accidentally transmitting on an unintended talk group. Consider the following scenario.

You have your radio set to a channel that’s configured for a statewide talk group, e.g., Indiana 3118. The repeater uses the same time slot for a regional talk group, e.g., Midwest US 3169. Someone calls you on 3169. Even though your radio is set to a channel that’s configured for 3118, you hear the call, because you disabled Group Call Match and the call is on the same time slot as the current channel. If you don’t change channels before you transmit, your answer will go out on 3118, not 3169, where you were called.

It is therefore important to look at your radio and know what talk group the calling station is using before you transmit. This isn’t a problem with Group Call Match enabled, because in that case, you would not hear any call that’s not on the talk group assigned to the current channel.

There is an exception to the above scenario. The radio has a timer called “Call Hold Time.” If you transmit before that timer expires, you will transmit on the last talk group the radio received, regardless of what talk group is associated with the current channel. The default Call Hold Time, however, is only one second. You can make Call Hold Time longer but doing so has disadvantages that are beyond the scope of this article.

RX Group Lists

Disabling Group Call Match as described above allows the radio to hear every talk group on which a repeater transmits on a single time slot. The radio provides a feature called “RX Group Lists” for users who want to monitor a smaller set of talk groups. The procedure below describes how to implement this feature.

If you have disabled “Group Call Match” as described above, reenable it. Group Call Match affects every channel in the radio, so RX Group Lists are irrelevant if Group Call Match is disabled.

In the menu tree on the left side of the CPS, under “Digital,” click “RX Group List.” A table will appear. Double-click the first row in the table. An RX Group List 1 dialog box will appear.

Using the same procedure described in earlier parts of this series for zones and scan lists, give the list a meaningful name and then from the “Available Contacts” list on the left, select the talk groups you want to monitor and use the right-pointing arrow button in the center to move each desired talk group to the “Contact Members” list on the right. When finished, click the “OK” button to save the RX Group List. See Figure 2 below. You may add up to 32 talk groups to the Contact Members list. If you wish to monitor more than 32 talk groups, use the “Group Call Match” procedure above instead of an RX Group List.

Now, assign your new RX Group List to at least one channel.

In the menu tree on the left side of the CPS, click “Channel” and then in the channels table, double-click the row of the channel with which you want to use the new RX Group List. A Channel Information dialog box will appear. In the right side of the dialog box, find the drop-down menu labeled, “RX Group List” and choose the list you created in the process above. Click the OK button to save the change. Repeat the above procedure for every channel with which you want to use the new RX Group List.

After you save the codeplug to your PC and write it to the radio, anytime you set the radio to one the channels that you modified as described above, that channel will receive transmissions from any talk group in the RX Group List that the repeater is transmitting on the same time slot as the current channel.