DSDPlus DSD+ .txt Files Miscellaneous Questions Thread

[CanesFan95]

I'm also interested in how the radio priorities work in DSDPlus.radios. Experimenting with different settings on a couple bust dispatch RIDs seems to make no difference.

And when editing DSDPlus.radios, sometimes the same radio ID is repeated on multiple lines. Evidently, DSDPlus.radios breaks everything out by talk group. So if the same RID is in the file multiple times, how does DSD+ decide which line to use for the alias, priority, override, etc.?

 

[dave3825]

I don’t believe any rid from the same system should be on more than one line let alone multiple in a row. Can you post a screenshot of the radios file showing an example?

 

[CanesFan95]

Take RID 4431442 for example. I find it in 2 different places:



And:

 

[mtindor]

Take RID 4431442 for example. I find it in 2 different places:

View attachment 164644

And:

View attachment 164645

Simple, one has a system ID tied to it one does not. So it will only use one, and that’s the one tied to the system ID. You will occasionally get things with the zero system ID even if you are monitoring a p25 system or some other system that is defined completely in the networks, sites, and frequencies files. If it captures voice traffic on a frequency that you happen to come upon before it is able to read the system ID, and it gets thrown into the zero system ID.

 

[CanesFan95]

Notes.txt says:

"If you have a second SDR device, you can run the 1Ra.bat file and the appropriate FMPx-VC.bat file and simultaneously monitor a second trunking system or site or conventional channel(s). To manually tune VC FMPx, press Esc once to take FMPx out of VC mode."

While I have 1R.bat and FMPA-CC.bat running and working, then I run 1Ra.bat and FMPA-VC.bat. But even after hitting Esc, the 2nd FMPA instance just says Idle with a blank spectrum and never starts tuning. Pressing C still gives a blank spectrum.



Am I doing something wrong?

 

[dave3825]

I run 2, sometimes 3 single dongle instances simultaneously. I simply created pairs so no matter which fmpx cc.bat I click, all that's needed is to click on the 1r, 1ra, 1r3.bat with the same port number. Under Control, I use Combined CC/VC Monitor.

 

[CanesFan95]

I think I found a workaround by hitting s / S (not case-sensitive) to put it in scanner mode which then wakes it up. Then you hit Esc and can tune from there.

 

[dave3825]

I don’t mess with s/S. I just pick an fmp24 cc and 1r pair with matching ports. Going to try 2 nooelec and 2 Airspy at the same time in the morning.

 

[mtindor]

I think I found a workaround by hitting s / S (not case-sensitive) to put it in scanner mode which then wakes it up. Then you hit Esc and can tune from there.

There ya go. When you are focused on the VC copy of FMPA, type ? and read what you see in the command prompt window associated with it. It'll give you the help. And S is one of the things you can do (if you want to scan a scan list) or C if you want to monitor a frequency or control channel on the VC copy separate from the CC instance.

 

[CanesFan95]

Next up is auto tune and PPM (parts-per-million) adjustments, a topic that has always tripped me up. Suppose I have an RTL-SDR dongle showing +225 Hz after running for at least 10 minutes:



Does this mean the dongle is + or - 225 Hz off-frequency? So If it's tuned to 461.77500 MHz in this case, does that mean without auto tune, the dongle is really at:

#1. 461,775,000 - 225 = 461,774,775 Hz = 461.774775 MHz ?

- OR -

#2. 461,775,000 + 225 = 461,775,225 Hz = 461.775225 MHz ?

My best guess is #1, the +225 Hz indicator means the dongle is too LOW, meaning the dongle is really tuned to 461.774775 MHz even though I told it go to 461.77500 MHz. FMP24.exe is compensating by adding the +225 Hz and telling the dongle go to 461.775225 MHz to make up for it so that the dongle will truly be tuned to exactly 461.77500 MHz.

Right or wrong?

 

[CanesFan95]

Continuing on, here I tune the same dongle to a higher frequency of 769.28125 MHz.



But this time it shows a +990 Hz. Is a dongle's off-frequency-ness not a linear relationship? How come it's only +225 Hz on UHF but jumps to +990 Hz on 700 MHz?

Which might tie in to my next question about PPM correction. Is the PPM number in Hz? So would I add a command line argument of -P-990.0 to compensate? Or is PPM not a linear relationship?

 

[dave3825]

Is the PPM number in Hz?

What is Frequency Stability? - everything RF

What is frequency stability in a crystal oscillator?

www.everythingrf.com

 

[CanesFan95]

What are the AMBE and IMBE unvoiced audio levels settings for? I don't understand what it's adjusting?

 

[dave3825]

What are the AMBE and IMBE unvoiced audio levels settings for? I don't understand what it's adjusting?

Changes from DSD+ 1.074 to DSD+ 1.101
-------------------------------------


DSD+: Control of AMBE and IMBE unvoiced audio levels has been added

-UA<num> AMBE unvoiced speech level (0-100) [-UA50]
-UI<num> IMBE unvoiced speech level (0-100) [-UI50]

pressing 'A'/'a'/'I'/'i' will also adjust the levels;
lower levels may reduce the "underwater" sound of some comms

The above switches and keyboard commands are used in the Public version.

In FastLane, they are only available in the DSDPlus menu.

 

[CanesFan95]

Well yeah, I saw that. But I mean what is "unvoiced speech level"? And what's the difference between IMBE and AMBE? I don't understand the concept of what this setting is and what it's adjusting.

If "lower levels may reduce the "underwater" sound of some comms", then I guess this is something to do with voice calls. But it's called "unvoiced speech level"?

 

[mtindor]

Well yeah, I saw that. But I mean what is "unvoiced speech level"? And what's the difference between IMBE and AMBE? I don't understand the concept of what this setting is and what it's adjusting.

If "lower levels may reduce the "underwater" sound of some comms", then I guess this is something to do with voice calls. But it's called "unvoiced speech level"?

99.9% of DSDPlus users do not care and do not mess with it. Furthermore, something close to 99% of DSDPlus have no clue, just like you or I.

But, a Google search of "mbe ambe unvoiced speech" lead me to this article:

https://www.dvsinc.com/papers/iambe.html

Look under the section "Development of MBE Technology" and read the paragraph starting with "Most CELP speech coders" and you might get some understanding.

 

[CanesFan95]

Understood.

How do we tell what # to use for each window for:

-_<num> Minimize selected windows at startup (bitmapped, 0-15) [-_0]

 

[CanesFan95]

The current DSD+ help options include:

Advanced decoder options:
-ds<num> Scaling factor (55-75; not used with D-Star or ProVoice) [-ds64]
-dd<num> Damping level (1-100; not used with D-Star or ProVoice) [-dd10]
-dv<num> Viewport size (1-30; not used with D-Star or ProVoice) [-dv20]

What are these for, or is this something to improve decode quality? What does each one mean and how do we decide how to adjust 'em?

 

[mtindor]

The current DSD+ help options include:

Advanced decoder options:
-ds<num> Scaling factor (55-75; not used with D-Star or ProVoice) [-ds64]
-dd<num> Damping level (1-100; not used with D-Star or ProVoice) [-dd10]
-dv<num> Viewport size (1-30; not used with D-Star or ProVoice) [-dv20]

What are these for, or is this something to improve decode quality? What does each one mean and how do we decide how to adjust 'em?

Read the whole text file, preferably before asking more questions. Anything you need to know about those settings, the best order in which to use them, etc is in the TXT file. And that very same DSDPlus.txt file explains the AMBE/IMBE unvoiced levels and why you might want to change them or not. Wealth of information in there. RIF!

-UA<num> -UI<num>
Controls AMBE and IMBE unvoiced speech levels; lower levels reduce "underwater" sounds.

And read the section down below called "Advanced Decoder Options" It tells all about ds/dd/dv. If you have a crappy signal (weak, interference, etc) you may be able to get a better decode by going through the process.


m

 

[CanesFan95]

Ok, understood. So what's an ideal decode score? Right now I get 56,134 on 700 MHz P25 with RTL-SDR dongle. DSDPlus.txt says "Adjust a single parameter to determine which value produces the highest score", but then later says "Rolloff: start at 1 and go up by 1 until the score starts trending down".

So is it better if the score is higher or lower? Thanks.