DSD-NEO help

[RobDLG]

I tested a recent nightly build of the dsd-neo "AppImage" under Red Hat Enterprise Linux 9.7, and was able to successfully scan a local P25 system!

I started in a basic command-line environment, and learned that I needed to ensure that the libXau, libxcb, and fuse-overlayfs packages were installed. Then I ran the following script.

#!/bin/bash

export TZ="America/Denver"

RTL_ID="0"

# Las Cruces P25 - https://www.radioreference.com/db/sid/13465
CSV_SITE="lc.csv"
#CSV_GROUPS="db/groups/391/391.csv"

# center frequency
#FREQ="853.309M"
FREQ="852.950M"

AGC="0"
PPM="0"
BW="24"

# trunking with RTL-SDR Blog V4
dsd-neo -ft -i rtl:"$RTL_ID":"$FREQ":"$AGC":"$PPM":"$BW":0:2 -T -C "$CSV_SITE" -o null -N 2> console_log.txt

Initially, I set the "center frequency" to the numerical center of the system's frequency range, but that didn't work as well as setting it to the currently active control frequency. Screenshot:




As it happens, many of the P25 channels are also on a currently operational EDACS system. When I tested dsd-neo on this EDACS system, though, it froze after the first call. I did not investigate further.

Nevertheless, seeing the P25 output was pretty cool. Thanks, @arancormonk!

 

[ki4hyf]

If you need to hear decoded audio, remove -o null from the last line in your script.

 

[arancormonk]

I tested a recent nightly build of the dsd-neo "AppImage" under Red Hat Enterprise Linux 9.7, and was able to successfully scan a local P25 system!

I started in a basic command-line environment, and learned that I needed to ensure that the libXau, libxcb, and fuse-overlayfs packages were installed. Then I ran the following script.

#!/bin/bash

export TZ="America/Denver"

RTL_ID="0"

# Las Cruces P25 - https://www.radioreference.com/db/sid/13465
CSV_SITE="lc.csv"
#CSV_GROUPS="db/groups/391/391.csv"

# center frequency
#FREQ="853.309M"
FREQ="852.950M"

AGC="0"
PPM="0"
BW="24"

# trunking with RTL-SDR Blog V4
dsd-neo -ft -i rtl:"$RTL_ID":"$FREQ":"$AGC":"$PPM":"$BW":0:2 -T -C "$CSV_SITE" -o null -N 2> console_log.txt

Initially, I set the "center frequency" to the numerical center of the system's frequency range, but that didn't work as well as setting it to the currently active control frequency. Screenshot:


View attachment 199144

As it happens, many of the P25 channels are also on a currently operational EDACS system. When I tested dsd-neo on this EDACS system, though, it froze after the first call. I did not investigate further.

Nevertheless, seeing the P25 output was pretty cool. Thanks, @arancormonk!

ah, i think i found the cause: on EDACS analog calls, if RTL squelch is disabled (sql=0), DSD-neo could stay on the voice channel after the first call and look frozen. i improved release detection and added a safety timeout, so it returns to the control channel instead of hanging. latest nightly build has the fix.

workaround for current build: set a real squelch value (negative dB), e.g. -70 to -90, and keep using -T with -fh/-fe and a correct EDACS LCN CSV.

let me know if that works

 

[RobDLG]

workaround for current build: set a real squelch value (negative dB), e.g. -70 to -90, and keep using -T with -fh/-fe and a correct EDACS LCN CSV.

let me know if that works

Yes, the new build works! Squelch at -40 gave good results. Setting it to 0 was also working.

#!/bin/bash

export TZ="America/Denver"

RTL_ID="0"

# Las Cruces EDACS - https://www.radioreference.com/db/sid/391
CSV_SITE="390.csv"
CSV_GROUP="391.csv"

# center frequency
#FREQ="851.941M"
FREQ="852.175M"

AGC="0"
PPM="0"
BW="24"
SQ="-40"
VOL="2"

# trunking with RTL-SDR Blog V4
dsd-neo -fh -i rtl:"$RTL_ID":"$FREQ":"$AGC":"$PPM":"$BW":"$SQ":"$VOL" \
  -T -C "$CSV_SITE" -G "$CSV_GROUP" -o null -N 2> console_log.txt

Screenshot:



Thanks for the quick response!

 

[RobDLG]

If you need to hear decoded audio, remove -o null from the last line in your script.

Yes, thanks! I did try that early on, and it was working properly, as I recall.

I actually lost track of why I disabled audio out, but now I remember. I had a system running Fedora 40 that I was using with dsd-fme. Fedora 40 is now end-of-life, and I figured upgrading to the current version, Fedora 43, would be straightforward.

I was wrong! I kept getting a USB error that prevented access to the SDR dongle. I tried blacklisting the built-in "rtl-sdr" kernel module, but that didn't help.

What did work was using a bare-bones Fedora 43, with no audio or graphics, just a command line environment with the libraries needed for dsd-neo.

That was weird. It seems something in the desktop environment is causing a conflict, but I haven't had time to figure it out. In the short term, I was planning to use dsd-neo to log calls on a new P25 system here, and that's already working!