Each repeater should be programmed in its own zone (group of channels).

Each TG (505, 380x, etc) should be programmed in its own channel in that zone.

Each channel must have its own receive group Рthis must contain ONLY the TG for the channel.  

Having multiple TGs in the receive group can cause some (Chinese) radios to jump TGs, creating chaos on the network.

You don’t need to program a rx group if you are using a Motorola, as the radio automatically defaults to the same rx group as the tx group.

The Chinese radios need a rx group to be programmed.

“Promiscuous” mode should NOT be used.