BER varies with TG seleected

Help with DMR issues
Post Reply
W4IND
Posts: 16
Joined: Wed Jul 21, 2021 2:57 pm
Location: Port Saint Lucie,Fl

BER varies with TG seleected

Post by W4IND »

I have a STM32-DVM/MMDVM_HS_Raspberry Pi Har(GPIO) configured for DMR. The sheet supplied with the modem said set MMDVMHost RXOFSET=0, TXOFSET=0. When using D-Dtar and an Icom ID-51 the BER was alwys 0% on any reflector. When I changed to DMR with a TYT 390 the BER was very high. Changed the offsets to -300 then with a PARROT test the BER was 0%. Changed to TG91 the BER was 04%. Changed to TG 3137 and the BMR was 0.1%. Some other TG's had as high as 1.4%. All are Green and work but I was wondering why it 0% on D-D-star and varies so much on DMR.
Kelton
W4IND
W4IND
Posts: 16
Joined: Wed Jul 21, 2021 2:57 pm
Location: Port Saint Lucie,Fl

Re: BER varies with TG seleected

Post by W4IND »

I tried running mmdvmcal. When I type in e and put in my frequency,435450000, mmdvmcal returns Received NAK to the SET_FREQ command from modem, 4. All commands return a Received NAK message. How dio I fix this new problem?
Thanks
Kelton
W4IND
Posts: 16
Joined: Wed Jul 21, 2021 2:57 pm
Location: Port Saint Lucie,Fl

Re: BER varies with TG seleected

Post by W4IND »

OK, I make a typo and tyed 435450 instead of 434450 for my frequency in my post. Guess I need to use preview and read carefully before submitting a post. It seems that it mislead you to see the problem as I was using a satellite frequency. The problem I am having with mmdvmcal is that ANY comand I use returns a NAK message. This indicates a communication problem between the script and the modem. Due to a lack of documentation on mmdvmcal, the modem processor, and pi star I am unable to troubleshoot this problem myself. Could you please point me in the right diection to correct this problem.
Thanks
Kelton
W4IND
W4IND
Posts: 16
Joined: Wed Jul 21, 2021 2:57 pm
Location: Port Saint Lucie,Fl

Re: BER varies with TG seleected

Post by W4IND »

My inquiring mind now knows why the BER varies with different transmissions and talk groups. Running mmdvmcal and keying the radio as the display scrolls the BER reads a lot of o% then a higher number then back to 0%. So it appears that the radio has some instability.
Post Reply