[HCARC] Baofeng radio and DMR issues?

[Fred Gilmore]

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


11/25/2016

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


Source of information: https://www.rmham.org/wordpress/