MOTOTRBO is a type of Digital 2-Way Radio. Motorola / MotoTRBO is a digital radio product originally and mostly marketed for Part 90 business use. The format is based on, and compatible with the European 2-slot DMR. It uses time Division Multiple Access (TDMA) to effectively accommodate two simultaneous users. A single 12.5 kHz channel is able to carry two simultaneous and independent conversations, or simultaneous and independent voice and data paths each with 6.25 kHz equivalency.
MotoTRBO features IP connection over the Internet to create a network of MotoTRBO repeaters. It also supports privacy and encryption. IP Site Connect is Motorola.
MOTOTRBO radios have the ability to scan an analogue and digital channel for activity so they can receive either. MOTOTRBO repeaters can be configured to operate in Dynamic Mixed Mode (DMM) which allows the repeater to switch between analogue and digital.
MotoTRBO uses a licensed, proprietary closed codec, the ABME2+ vocoder algorithm, which is currently licensed and owned by DVSI Inc. Therefore it is not a true ham radio open system, due to the proprietary codec and the support for encryption, yet the FCC now allows its use on ham radio bands.
Current equipment (2016) seems to be primarily vehicle mobile units and even more so hand held HT units. Most ham operators using MotoTRBO radios are using HT models. Most available radios are manufactured by Motorola company.
For amateur radio use part 90 radios had to be programmed to operate on ham frequencies. Now there are some offerings that are actual Part 97 intended for amateur use.
Each MotoTRBO radio has an ID that has to be registered and is tied to the callsign of the user. MotoTRBO utilizes "talkgroups."
Non-Motorola DMR Transceivers
Programmable but without a VFO.
- Tytera TYT MD-380
- Quantun QP-2100
- Vertex VXD-720
- Retevis RT3
- Connect Systems CS700
- Connect Systems CS750
- Connect Systems CS800
- Connect Systems CS7000*
Not filed programmable and no VFO.
The Connect Systems CS700 had many firmware bugs which plagued the model. The CS750 can be thought of as a CS700 with better firmware. However, consider it an "alpha" quality firmware gone to "beta" but still not fully stable. The CS800 is a vehicle mobile version.
Connect Systems radios do not support UDP compressed headers. To receive a text message from a Motorola radio user, he will have to disable UDP compressed headers.
Compatibility Issues: Voice compatibility does not seem to be a problem across available DMR ham repeaters. The roaming feature of automatically going from tower to tower does not seem to work at all with non-Motorola radios. There is some texting support depending on the radio and mode.
It is important to ensure the DMR radio is DMR Tier 2 compatible.
Digital ham radio modes
- Yaesu Fusion