Tony VK3CAT recently alerted me to a bug he found when using the GD-77 in VFO mode on DMR
The bug manifests itself if you change the frequency band that the VFO is using. The bug does not seem to happen absolutely all the time, but seems to be fairly easy to reproduce.
To see the bug, you just have to change the “band” that the VFO is using.
e.g. if you have the VFO set to 439.200 and it was working OK, for both Tx and Rx, and then you enter the frequency of 144.800….
The GD-77 seems to stop transmitting audio.
The green LED on my receiving radio was illuminated when there is an incoming signal, and the display shows the DMR ID number and TG of the transmission, but there is no audio whatsoever.
Enabling the monitor mode does not seem to make any difference, nor does manually changing the Timeslot or the Color Code using the Set->Radio config menu
Tony reported if he power cycled the GD-77, that the problem was resolved, but this didn’t seem to fix it for me.
The only thing that seemed to work for me, was to go into the Radio Config menu, and set the channel type to FM, and then set it back to DMR.
I initially thought this was a Rx bug, but Jason VK7ZJA has done some testing and confirmed it a Tx audio bug, where the audio part of the data transmission appears to be empty.
Jason reported a workaround for the problem is to switch to memory mode and then back to VFO mode, but I’ve not confirmed whether it makes any difference if the memory is on the same band as the VFO.