DSD+ FL (2.39) vs DSD+ 1.101

[kd6dcn]

Hello,

I have been having good success with DSD+ 1.101 with various 820T2 receivers. I recently upgraded to the Fastlane version, however, it doesn't work for me. I'm using this to monitor a multi-site DMR Con+ system.

The receive in FMP24 looks fine, and the waveform in the receive window of DSDPlus looks fine as well. The symptom is error rates are too high to be useful. It takes about 30 seconds to just get a good neighbour list. Audio decode is completely unintelligible.

Errors are of this form on the control channel:
Sync:+DMR
+DMR CACH ERR slot1 BS DATA DCC=6 Idle ERR15
Sync:+DMR
+DMR CACH ERR slot1 BS DATA DCC=6 Idle ERR54
Sync:+DMR
+DMR CACH ERR slot1 BS DATA ERR3 DCC=6 Voice Hdr ERR12 ECC FAIL
Sync:+DMR
+DMR CACH ERR slot1 BS DATA DCC=6 TLC ERR12 ECC FAIL
Sync:+DMR
+DMR CACH ERR slot1 BS DATA DCC=6 TLC ERR15 ECC FAIL
Sync:+DMR
+DMR CACH ERR slot1 BS DATA DCC=6 Idle ERR51
Sync:+DMR
+DMR CACH ERR slot1 BS DATA DCC=6 Idle ERR59
Sync:+DMR
+DMR CACH ERR slot1 BS DATA DCC=6 Idle ERR55
Sync:+DMR
+DMR slot2 BS DATA DCC=6 Idle ERR34
Sync:+DMR
+DMR CACH ERR slot1 BS DATA DCC=6 Idle ERR1
Sync:+DMR
+DMR slot2 BS DATA DCC=6 Idle ERR35
Sync:+DMR
+DMR slot2 BS DATA DCC=6 Idle
Sync:+DMR
+DMR slot1 BS DATA DCC=6 Idle ERR48
Sync:+DMR
+DMR CACH ERR slot1 BS DATA DCC=6 Idle ERR34
Sync:+DMR
Sync:+DMR

I've tried the various ds/dd/dv tuning parameters; ds made a very slight difference.

FMP24 -rc -i1 -o20001 -P0.0 -f451.9125
DSDPlus -rc -i20001 -v3 -ds66 -Pwav -fr

Any ideas on what to try? Also, is there a way to reduce the sampling rate in FMP24? It doesn't seem possible to use the other 1MHz FMP with the FL DSDPlus. (if I try, FMP gives the error "a non-blocking socket operation could not be completed immediately" and no audio moves across the tcp link)

Thanks,
Jon

 

[kd6dcn]

Looks like my problem is something with FMP24, and probably the sampling rate. I captured RAW files in both versions of FMP/DSD+ and FMP24/DSD+FL. The FMP captured raw decodes fine in both versions of DSD+, and the FMP24/DSD+FL recording fails in both versions of DSD+.

So, I guess that means my question is simpler:
Is there a way to run the 1MHz version of FMP with the FL version of DSD+; or is there a way to connect to remote rtl_tcp tuner instances?

Thanks
Jon

 

[DaveNF2G]

I see your frequency correction to the dongle is zero. Have you tried calibrating your tuning?

 

[slicerwizard]

Try changing the channel filtering bandwidth in FMP24.

If that doesn't help, try using a virtual audio cable instead of TCP linking.

 

[kd6dcn]

Hi,

I've continued to experiment here. Changing bandwidth only makes things worse, the defaults for FMP work best. I have 5 dongles; the two that work best have tuning calibrations of less than 1ppm. I've now tried on three different machines, and the result is the same. The 1.101 version with FMP at 1msps works OK, but the fastlane version at 2.4msps is not reliable. I guess I'll stick with 1.101 for now.

For the record, it appears to be on the FMP/FMP24 side of things. Capturing the raw audio and replaying in the other version of dsdplus shows that the problem stays with FMP24, and captures from FMP are significantly better.

Thanks for your help.

Jon

 

[dave3825]

Have you played with the gain settings in fmp/fmp24 ?

 

[M105]

Try turning off auto center tuning.
auto center tuning can be enabled/disabled on the FMP24 command line:

-a<num> Enable/disable auto center tuning (0-1) [-a1]

auto center tuning can be enabled/disabled while FMP24 is running:

A toggle auto center tuning

 

[DaveNF2G]

I doubt that the issue is with either piece of software, as many of us are using that very combination to monitor such networks as OneVoice without any difficulty.

 

[kd6dcn]

Hi,

Thanks everyone for the help. I ended up doing several raw recording tests and comparing. It seems clear that I'm dropping samples on all of my machines at 2.4Msps with FMP24. Where there are CACH ERRs and a decoding problem, there are noticeable little chunks missing in the raw capture -- They sound like clicks when listening to the raw audio and are noticeably different than the sound of the digital signal. (Tried different gains as appropriate for different antennas, tried centring on and off, upper and lower insert, etc. Only thing that makes things reliable is going to the older 1Msps version, so I'm pretty confident this or something similar is my issue.)

Jon

 

[M105]

You got me. Like somebody else said there are lots of us using FMP24 with no problems. You might try a fresh clean install of the FL version in a fresh clean folder. My only other thought is that the computer you are running it on is marginal on cpu power but since you say you have tried it on three systems with the same result that seems unlikely.

 

[slicerwizard]

I suspect that FMP24 is auto switching to PSK decoding mode, which would mess up DMR decoding. Using a virtual audio cable disables that functionality.