TLDR:
Some versions of the Baofeng DM-32UV radio appear to have low TX audio levels even with the mic gain set to the max level (5).
A new version of the firmware appears to resolve the matter but requires a bit of work on the behalf of owners.
This post explains the background, steps taken and outcome, as well as providing links to the files.
All changes made by you, to your equipment are, at your own risk.
Issue
Recently, I reviewed the DM-32UV radio and noted reports of low TX audio levels on DMR. I was unsure if this problem was firmware related or a hardware issue.
Given the build quality of the radio, I had my doubts about it being hardware and thought i would be able to use an external mic, pending a firmware update.
The radio was running DM32.01.01.040 when it was received and I could find no updates from Baofeng.
This evening, I had numerous reports of extremely low audio on the radio and made a bit more effort to track down some updates.
This led me to Facebook, a site I left a year ago and have no desire to return to. A post, (below) indicated there was a .046 release available as a file from their group. Unfortunately, this meant temporarily creating a Facebook account to access the file.
To complicate matters, the instructions were in Chinese, suggesting a helpful person at Baofeng had shared the update but perhaps, unofficially.
Steps Taken
I managed to download the files, there were two required.
- The firmware itself – DM32.01.02.46
- An updated CPS package, which by default, loads in Chinese – V1.37 (the latest official version I could find was V1.28 which is what I had installed on my Windows VM).
I removed V1.28 of the CPS from the Windows system and installed V1.37. I would expect trying to load updated firmware, with a few new features, to a CPS that isn’t designed to handle it could lead to problems.
The CPS loaded in Chinese and I worked out which menu it was to change it (layout is the same as V1.28).
Next step was to test the radio could be read by the CPS before attempting make changes. This was successful.
I moved on to the Tool menu then Firmware upgrade. Selected the .bin file and hit Upgrade. This showed a Communication Error.
A little digging indicated that the radio needed to be placed in upgrade mode:
Power off the radio
Power back on whilst holding the PTT and the button immediately below. You can confirm this is successful because the screen will remain blank and the green LED on top will light up.
This did not work whilst the cable was connected – so do this before connecting back to the cable.
Again, upgrade did not work.
More digging, we need to change the communication from Com Port to USB (Setting – Com Setting – Select USB from the Com Type drop-down).
This time, the radio updated.
Success?
Previously the Digi Mic Gain had 5 levels. The new firmware includes Enhance 1, 2 and 3. Naturally, I selected Enhance 3.
A quick QSO suggests the audio is a lot louder and given the firmware now includes these options, indicates Baofeng are aware there is an issue with the current firmware, although i suspect this version is now being installed at the factory so people purchasing new may not have this issue to deal with.
I have noticed my code plug is now not quite right, various values have been lost so will require some tweaking. I tried to load a saved version but the changes were not applied fully so will require a bit of re-working. Manual changes made on the radio and to the CPS software post-hoc have been accepted.
At the time of writing, another QSO or two would be necessary to be certain the matter is resolved, but on the face of it, would appear so. I have decided to host these files on my onedrive should anyone need them and also not be a Facebook member.
Disclaimers:
I trust that the group owners won’t object but will happily remove the files if they do.
As always, any changes to system firmware is at your own risk and this information is supplied as my experience and without warranty. No support can or will be offered!
That said, If you need it, i hope this is helpful.
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