Voice/Control Channel Decoding Software Cach Errors = Choppy Audio in DMR Voice Decode - DSD+ FastLane 2.155

[AB9NN]

I am doing DMR scanning with confirmed freq's - small number of freq's. Good antenna, etc.. I do get audio but it short and choppy to garbled. I see Cach errors on the output. Suggestions? My two bat files, FMP24.cfg file contents and output documentation are below:

FMP24 -i2 -o20003 -P0.0 -s1

DSDPlus -e -i20003 -fr -o4 -O NUL

2.4 ; sampling rate (1.0, 2.0 or 2.4)
1024 ; spectrum window width
32 ; FFT size (8k, 16k, 32k)
20 ; spectrum update rate in Hz - Original was 10
5000 6250 7500 12500 15000 20000 25000 ; step size table; units = Hz;negate default
. ; DSD+ path
.\FMP-FreqList.csv ; primary frequency list CSV path\filename
.\FMP-FreqList2.csv ; auxiliary frequency list CSV path\filename
miles ; search units (miles or kilometers)
99.9 ; search distance
44.630978 -86.072480 ; search origin

DMR CACH ERR slot1 BS DATA ERR2 DCC=5 TLC ERR12 ECC FAIL
CACH Sig ERR2
+DMR CACH ERR slot2 BS DATA ERR1 DCC=5 Idle ERR11
+DMR slot1 BS DATA ERR3 DCC=1 Rate 3/4 Data FEC FAIL
+DMR slot2 BS DATA ERR2 DCC=5 Idle ERR24
+DMR slot1 BS DATA ERR1 DCC=5 TLC ERR14 ECC FAIL

 

[mtindor]

I am doing DMR scanning with confirmed freq's - small number of freq's. Good antenna, etc.. I do get audio but it short and choppy to garbled. I see Cach errors on the output. Suggestions? My two bat files, FMP24.cfg file contents and output documentation are below:

FMP24 -i2 -o20003 -P0.0 -s1

DSDPlus -e -i20003 -fr -o4 -O NUL

2.4 ; sampling rate (1.0, 2.0 or 2.4)
1024 ; spectrum window width
32 ; FFT size (8k, 16k, 32k)
20 ; spectrum update rate in Hz - Original was 10
5000 6250 7500 12500 15000 20000 25000 ; step size table; units = Hz;negate default
. ; DSD+ path
.\FMP-FreqList.csv ; primary frequency list CSV path\filename
.\FMP-FreqList2.csv ; auxiliary frequency list CSV path\filename
miles ; search units (miles or kilometers)
99.9 ; search distance
44.630978 -86.072480 ; search origin

DMR CACH ERR slot1 BS DATA ERR2 DCC=5 TLC ERR12 ECC FAIL
CACH Sig ERR2
+DMR CACH ERR slot2 BS DATA ERR1 DCC=5 Idle ERR11
+DMR slot1 BS DATA ERR3 DCC=1 Rate 3/4 Data FEC FAIL
+DMR slot2 BS DATA ERR2 DCC=5 Idle ERR24
+DMR slot1 BS DATA ERR1 DCC=5 TLC ERR14 ECC FAIL

Either you aren't getting a good signal, even though you claim to be getting a good signal, or you are monitoring a frequency with multiple DMR signals overlaying each other. Notice the DCC=1 / DCC=5 alternating. Some may disagree, but you need a clear 20 dB+ SNR to get clean decodes. And you don't want to be pumping up the gain to achieve that minimum if it means that it's swamping out the frontend from other strong signals.

 

[cg]

You could sit on each of the channels and see if you can clearly monitor them without scanning. If not, having them in the scanlist will frustrate you more.
Also, now you are using multiple dongles, how do you have the antennas connected? a bunch of "T"s or a good powered multicoupler? You need to look at each part of the system you have built and figure out the weakness and then look for specific solutions.
Antenna, height, coax, connectors, computer power, multicoupler, powered USB hub, outside interference, etc, will all affect how you hear all but the strongest signals.

chris

 

[AB9NN]

Thanks for thoughts on signals. At first I dismissed them as crazy thoughts. Later, I was scanning some digital frequencies and turned my beam to a direction I thought most traffic would be emanating from. I was right - there was a good amount of traffic. But it was choppy. We live in a pretty hilly terrain of the sand dunes areas of the Lake Michigan coastline. I figured there was a sand dune in the path. Later, I turned the beam to a different direction and had the back of the beam to the prior direction. Those same signal sources now came in crystal clear! I was surprised. The culprit? Distortion through and through. Probably the receiver being over-driven. One of these days I need to get some different connectors and try my vertical antenna. It should have less gain and doesn't have a pre-amp which probably caused the distortion. Good to keep an open mind I find... Thanks.

Jon