DSD+ FL 2.113 Con+, 2 x rtl, BW issue?

[TheButcher]

Hello.

I am monitoring a Con+ trunking site.

In my .bat file used to launch, I have added -b12.5 to both CC and the VC dongles. CC dongle obeys, ie. stays at 12.5kHz BW, but the VC one reverts to 7.6kHz.

This causes stuttering in the decoded voice.

I am using FMP24 for both...


ps. If I use the "b" or "ctl + b" key combinations on VC, BW changes, but it reverts to 7.6kHz.


What am I doing wrong???


Thanks!

 

[TheButcher]

START FMP24 -i1 -o20001 -P62.0 -fXXX.XXXXX -_3 -b12.5 -g32.8
START FMP24 -i2 -o20002 -P34.0 -rv -_3 -b12.5 -g32.8
START DSDPLUS -rc -fr -i20001 -v0 -e
START DSDPLUS -rv -fr -o1 -v0 -e

I have removed frequency of CC on purpose.

Thanks.

 

[TheButcher]

f offsets are correct (in my case), so long as dongles have warmed up! I am purchasing a set of xtl ovenised dongles. But I would like to use both of my old dongles too.

And the forced -b command is buggy???

 

[DaveNF2G]

I don't know if this will help, but try -b-12.5 on your voice following copy of FMP24.

Note the extra - after the b. According to the inline Help, it sets initial bandwidth and ignores suggestions from DSD+. It could be that DSD+ is sending bw info to the second receiver.

 

[slicerwizard]

In my .bat file used to launch, I have added -b12.5 to both CC and the VC dongles. CC dongle obeys, ie. stays at 12.5kHz BW, but the VC one reverts to 7.6kHz.

This causes stuttering in the decoded voice.

I am using FMP24 for both...

As noted, -b12.5 is not a bandwidth lock command. Also, if 7.6 kHz bandwidth causes stuttering, your dongles (or possibly the transmitter(s)) are likely off frequency. Enabling auto center tuning (-a1) should fix that though. IIRC, -a1 is the default, so unless you disabled it with -a0, signals should self-center.

Have you looked at the zoomed spectrum display on the VC side? Is the signal centered in the bandpass region? Does the bulk of the signal (to at least 20 dB down) fit in the bandpass region? Maybe post an Alt-PrtSc grab...

 

[TheButcher]

Ah I tried -b-12.5 and eureka! Thanks Mr. DaveNF2G.

Thanks again Mr. slicerwizard I love your work (TETRA). Just need some time to test it out here.

The above command has worked. I added a "-" on both VC and CC. No worries or complaints from DSD+ FL. There is still a bit of stuttering / quantisation, but at least the VC is obeying my command! I did not see the "-" bit on the DSD+ FL instructions.

My 2 old v2 realtek dongles are about +32 and +34 respectively. I own a v3 rtl-sdr.com one (as stated) and a 2nd one is in the mail.

I think issues have occurred just after dongles have been activated. Once warm, they are better. Issue is, some of the 8 repeaters on the Con+ system are of f by a tad. Software compensates well, but because of slight hysteresis, there is stuttering occurring on occasion.


Thanks for the help lads...

 

[TheButcher]

ps. I am not using -a0.

https://forums.radioreference.com/attachment.php?attachmentid=65909&stc=1&d=1537942956

I have removed f and TG names on purpose...

 

[TheButcher]

pps. I need to run such high gain (here in the city) as I am running thru an RF splitter to both dongles, ie. just using 1 ant. I must obtain a wide-band RF preamp one day and use a dedicated 800MHz ant.

 

[TheButcher]

"My 2 old v2 realtek dongles are about +32 and +34 respectively."

Should read "My 2 old v2 realtek dongles are about +34.0 and +62.0 respectively."