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.
Performance of three DMR Tier II radios compared. From left to right: Tytera MD-380, Baofeng DM-5R, Motorola XPR 6550. The Baofeng has the Tier II update applied, making it equivalent to a DM-5R Plus.
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.
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During 2016 we have noted some new and good DMR radios, and unfortunately we have also seen some radios which cause concern. The radios in question are the Baofeng DM-5R, TYT MD-398 and the Radioddity GD-55.
At this time Rocky Mountain Ham Radio is requesting that amateur operators refrain from using the Baofeng DM-5R, TYT MD-398, the Radioddity GD-55 radios on the RMHAM or DMR-MARC Repeater Systems. This request also includes clones of the above radios such as Pofung, Retevis, Chierda, VITAI, Juentai, SAMCOM, Zastone, HYDX, etc.
Early tests show serious problems with these radios which will jam other users and severely degrade the repeater system. Further tests are planned and we will keep our members and users informed of the results on the www.rmham.org web site. This request does NOT pertain to the new firmware release of the TYT MD-380 and MD-390 and the use of these radios remains acceptable. We do strongly recommend updating to the most recent firmware for these units. In addition you can find a list of radios known to properly interoperate with our system here DMR Radios, as well as sample code plug to program your radios Code Plug Samples.
In a nutshell here is what is being observed with these radios. When these radios transmit on Time Slot 1, Rocky Mountain Wide on most of the RMHam repeaters, they will actually transmit for a significant amount of time within Time Slot 2, which on the RMHam system are usually North, South or Denver. The net result? These radios are, in effect, jamming Time Slot 2 or at the very least causing harmful interference to any potential user in Time Slot 2. The user of the Baofeng DM-5R, TYT MD-398, Radioddity GD-55 radios or their clones will be able to use Time Slot 1 and will have no idea they are producing harmful interference to other users.
If you already own one of these radios all is not lost. You do have some options. These radios appear to function normally in FM Analog and DMR Simplex modes. If you purchased your radio from Radioddity or their Amazon affiliate they are honoring the 30-day 100% satisfaction guarantee. The manufacturers and importers are not currently considering this a product flaw. The radios and upgraded firmware are advertised as Time Slot 1 only. They are not currently addressing the jamming issue. For the details concerning the protocols and more technical details See Technical Information
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Mike Lozano K0NGA Class Instructor
Saturday November 19 found almost 30 students attending the second of the this terms courses on amateur radio topics. This month was DMR (Digital Mobile Radio) which gave an in depth look at this modes technology. The course covered everything from the basics of of the, including the theory of operation of the TDMA (Time Division Multiple Access) which allows two separate conversations on one repeater along with the two DMR networks available in Colorado. The Rocky Mountain Ham Radio network and the DMR-MARC Network. This comprehensive 3 hour course reviewed best operating practices, a introduction to some of the DMR capable radios available and the techniques used in programming the radios. You can obtain the course slide material in Adobe pdf format at the Course syllabus link under the RMHAM University Tab above. There are still courses available on a range of topics that will be held monthly, December through April, on the 3rd Saturday from 8 AM – 11 AM. Registration is $10 and features a pizza lunch at the conclusion of the course. Advanced registration is required to insure we have pizza for all! Check out the courses offered and feel free to register at the RMHAM University Tab above.
Boulder Amateur Radio Club’s annual hamfest at the Boulder County Fairgrounds in Longmont was a great event and lots of deals were found. Rocky Mountain Ham Radio cleared out a few estates worth of equipment and a few pieces of equipment. We all had a good time and had a few first-timers show up to help out with sales.
We all went to our after-hamfest tradition to the Rib House in Longmont and had a wonderful meal and a chance to chat with lots of friends and catch up.
We’re going to start our fall curriculum this month for Rocky Mountain Ham University. See the menu above for more information.
The next hamfest event we will be attending is the Northern Colorado Amateur Radio Club hamfest at the Ranch in January.
Rocky Mountain Ham Radio was happy to deploy our Communications Trailer September 10th in support of the Civil Air Patrol’s Colorado Wing as they conducted a communications exercise. The first phase of the exercise consisted of originated messages from the RMHam Trailer being relayed from Fort Collins to Grand Junction using aircraft flying in assigned sectors between the two airports, while amateur radio sent other messages using an IRLP link between ARES (R3 D2) and Mesa County RACES. The second portion consisted of having operators on the ground relay messages using a CAP airborne repeater (strapped in the back seat) of a CAP aircraft. During this period a second aircraft flew in from Cheyenne with a second airborne repeater and relieved the first aircraft “on Station”. During both phases, the CAP operators used their portable HF equipment to establish communications on CAP frequencies to Idaho and other locations. Eric Schwarm N6RFI, who was the exercise lead thanked us “We have always had to relied on our own vehicles or borrowed locations as bases for our exercises, we really appreciated Rocky Mountain Ham Radio allowing us the use of their trailer for this exercise “. Participating for RM Ham where David KØPWO (who missed the photo op!), Chris KDØZYF and Wayne NØPOH.
Click on RMHAM University above for more information and course syllabus. Our fall/winter class curriculum has been posted and we’ve got another great year of learning for you. Our classes are limited in number, so make sure you sign up early. Pizza lunch will be provided for your registration fee.
A few members from RMHAM activated the Great Sand Dunes National Park (NP25) from August 11-13th. The ARRL National Parks on the Air year long event has been a huge success in getting hams out to the parks and showing off their portable operating skills while teaching the public about amateur radio.
Neal Tew – KD0MBL, Jeff Carrier – K0JSC, and Amanda Alden-Carrier-K1DDN, members of RMHAM had fun setting up 2 portable operating stations from the park’s picnic area during all three days. Band conditions were less than favorable, so most QSO’s were made on 20m. Other QSO’s were made on 40m and 2m. Put to good use was RMHAM’s QRV3, which supplied generator power and a home for the hamstick antennas. Neal operated his station on solar and battery power supplied by his trailer fitted with two 120 watt solar panels.
Visitor turnout was low, but those who did make it had a great time. One of our visitors was from Dayton and while not a ham knew all about ham radio! A big thanks goes to Dave Newmyer – N0KM and John Fink – W0DNR who assisted with making contacts. There were a few public visitors who needed a table to have lunch and were lucky enough to learn about amateur radio at the same time.
When the bands are bad, they re-enacted Star Wars.
344 QSO’s were made in a combined time of 15 operating hours. NPOTA chasers were happy to work a new one. One more bonus for the chasers, the Old Spanish National Historic Trail runs through the park. Therefore they all got a two for one! NP25 and TR19.