Problems with New Baofeng DM-5R, TYT MD-398 and Radioddity GD-55 Models

By  | 11/25/2016 | Filed under: Uncategorized

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