Beofengs and their Ilk-Banned
Yes, but not like you think.
As most here who have spent time reading this site know I hate these things. They transmit out of band, they are not certified for anything they can transmit on. The antennas are trash from the factory and they break with annoying regularity.
However, a repeater system has banned them
Apparently as technology has spread for Digital Mobile Radio another issue has come up which has caused the operators of DMR-MARC series of repeaters to ban the use of Chinese radios which have been repeatedly shown to cause harmful interference
Rocky Mountain Ham Radio continues to investigate alarming problems with recently released low-cost DMR Tier II radios. This article focuses on the Baofeng DM-5R Plus and Baofeng DM-5R with Tier II firmware update. A later article will examine the Radioddity DM-55 / Tytera MD-398.
Our tests find that the Baofeng DM-5R is unfit for DMR use and degrades the repeater network. We will continue to forbid the use of it on our systems.
Here are our findings.
The short version:
“Does the DM-5R transmit a legitimate digital voice signal on timeslot 1?” Yes.
“Does the DM-5R transmit a legitimate digital voice signal on timeslot 2?”
Uncertain. Baofeng says no, but we have been able to activate talkgroups which are only carried on timeslot 2. This requires more research. The radio transmits a copy of the TS1 signal on TS2. It is not supposed to do this. (Updated Jan 5 2017)
“When transmitting on one timeslot does the DM-5R jam the other timeslot?” Yes.
“What does the jamming signal look like?” It
appears to be is a duplicate of the intended signal. This requires more research. (Updated Jan 5 2017)
“Are you sure you weren’t using the radio in Tier I mode?” DMR Tier I FDMA and Tier II TDMA are completely incompatible. If the radio were in Tier I it would not be able to activate DMR repeaters or work with other Tier II radios in digital simplex. Our DM-5R with the Tier II update is able to do both of those things.
“Has the Baofeng DM-5R been tested and approved by the DMR Association?” No.
“Will Rocky Mountain Ham Radio allow the DM-5R to be used on its amateur DMR repeaters?” No.
“What if I ignore your ban and use the DM-5R on the RMHam network anyway?” You will raise the noise floor at the repeater for anyone attempting to use the other timeslot. This is called jamming. It is poor practice at best. If you choose to do this anyway it could be interpreted as deliberate interference which is forbidden under FCC regulations.
“Isn’t ham radio just a fun toy? What am I hurting by using the Baofeng DM-5R?” We cannot speak for other DMR networks but Rocky Mountain Ham Radio has prioritized robustness and reliability from the beginning. We want our repeater network to perform flawlessly in the case of a disaster and this philosophy shapes every decision we make. This radio is more than a nuisance, it poses a direct threat our ability to respond to a disaster.
“Are other DMR networks banning the DM-5R?” Yes. Hoosier DMR is known to have banned them in late November. There are likely to be others.
“Will you be able to identify hams who are using the DM-5R?”
We’re working on it. Yes. (Updated Jan 5 2017)
“Will Baofeng update this radio to allow correct use of both timeslots?” Given their responses to date this seems unlikely. Some teardowns indicate it may be impossible due to inadequate switching speed of the RF section, although we have not verified this.
“What has their response been?” Baofeng and Radioddity have consistently stated that if you wanted a two-timeslot radio you should have purchased one.
“Have they addressed the issue of jamming?” Not that we have seen.
“Are there any other issues with these radios I should know about?” The Baofeng DM-5R frequently glitches while reading or writing memory channels. This causes them to receive and transmit incorrect talkgroup parameters.
“Are the ARRL or FCC doing anything about this?” Not yet. They took effective action on bad GFCI outlets and grow lamp ballasts once enough people complained. Consider writing some polite letters.”
“Motorola radios and the software to program them are really expensive! I don’t even know if I will like DMR. Are there good, affordable entry-level radios?” The Connect Systems CS750 is an excellent performer at $180. The Tytera MD-380 at $120 is pretty good. Programming software is free for both of these.
“Are those radios dual band?” No. At this time there are no other dual-band DMR radios on the market. Connect Systems has announced one with an expected availability in early 2017.
“What am I missing by having a single-band DMR radio?” Mostly you lose the ability to operate DMR while traveling to regions where another band dominates. In the Colorado Front Range nearly all DMR activity is on 70cm. Rocky Mountain Ham Radio will be deploying 2m DMR to Colorado’s Eastern Plains in the near future.
What does this mean?
It means you should have bought a decent type certified radio for use as a DMR for yourself and groups. Buying low end does your group a serious disservice and the owners of DMR repeaters are actively tracking users of these radios for the FCC for creating, knowingly, harmful interference.
A long overdue progression with these substandard radios.