DSDPlus Help with sdr software

[silberj]

Another option as you start on your endeavor is to take a look at SDRTrunk. It's java based, has it's own decoder and you may find it easier to use. As mentioned above, there's lot's of options with software and configurations depending on what you want to monitor.

I can't post a link from my work computer, but a simple search for the title will get you there.

 

[ArloG]

I used SDR# at first on an IC-R8500 years ago with discriminator output.
Your RTL dongle consider as a radio without switches and knobs. You need a front panel to do everything. Even to 'turn it on'.
Preamp and front end filtering (very little on these if at all) is on the radio, or "donngle".
Software is used to control tuning, modes like SSB, AM, FM, Etc.
ALL of the signal processing is done in software. For FM stereo the entire circuit is done in software. Even RDS decoding.
Tuning is done in the dongle by way of software. Signal's are amplified in it and sent to software.
Now. So you know. We COULD upload what is known as the RF capture files, I/Q files and you could download and decode them using SDR software. One example would be a Meteor satellite pass. You could get the file and process it on your software and the various modules could decode and produce the same image we have.
I hope you thought forward enough to also order antenna port adapters and consider a proper antenna to use with this mysterious new toy.
The mystery will go away soon. But learn the basics before going on to more advanced decoding software.

 

[bobruzzo]

I used SDR# at first on an IC-R8500 years ago with discriminator output.
Your RTL dongle consider as a radio without switches and knobs. You need a front panel to do everything. Even to 'turn it on'.
Preamp and front end filtering (very little on these if at all) is on the radio, or "donngle".
Software is used to control tuning, modes like SSB, AM, FM, Etc.
ALL of the signal processing is done in software. For FM stereo the entire circuit is done in software. Even RDS decoding.
Tuning is done in the dongle by way of software. Signal's are amplified in it and sent to software.
Now. So you know. We COULD upload what is known as the RF capture files, I/Q files and you could download and decode them using SDR software. One example would be a Meteor satellite pass. You could get the file and process it on your software and the various modules could decode and produce the same image we have.
I hope you thought forward enough to also order antenna port adapters and consider a proper antenna to use with this mysterious new toy.
The mystery will go away soon. But learn the basics before going on to more advanced decoding software.

I did order an adapter so I can connect dongle to antenna. I will use my discone. I will start off by trying to get at least an FM broadcast to come in. But I want to mostly monitor the conventional scanner stuff for now. Long term goal is to be able to monitor my local P25 simulcast system because even with having an sds200 I still get simulcast distortion. But I am not sure how well that is gonna work either.

 

[ArloG]

I did order an adapter so I can connect dongle to antenna. I will use my discone. I will start off by trying to get at least an FM broadcast to come in. But I want to mostly monitor the conventional scanner stuff for now. Long term goal is to be able to monitor my local P25 simulcast system because even with having an sds200 I still get simulcast distortion. But I am not sure how well that is gonna work either.

I'll be interested in finding out too. These "basic" dongles have little or no front end filtering. My RSP2 will get pretty strong images from a pager transmission close to me. Depending on how high the gain is set. You cant really control things like this, multipath, etc.
But I/Q processing does help and that's what software does nicely. In time you may consider a directional antenna depending what and where you prefer receiving. Just don't worry about the big stuff at first and learn your radio and software. I may add that you will want a very good ferrite shielded USB cable like a Tripp Lite as pc noise will be noticeable.

 

[bobruzzo]

I'll be interested in finding out too. These "basic" dongles have little or no front end filtering. My RSP2 will get pretty strong images from a pager transmission close to me. Depending on how high the gain is set. You cant really control things like this, multipath, etc.
But I/Q processing does help and that's what software does nicely. In time you may consider a directional antenna depending what and where you prefer receiving. Just don't worry about the big stuff at first and learn your radio and software. I may add that you will want a very good ferrite shielded USB cable like a Tripp Lite as pc noise will be noticeable.

Yeah I dont know if I will have a problem with interference. There is only 1 LOUD pager on 152.600 but I dont know where it is. Doesnt seem to affect anything I listen to. I have a spare 800mhz yagi that I am not really using. It's up on mast but not connected to radio. I first gotta get dongle. It is supposed to arrive later today in mail. Then still waiting on the adapter. Once I get these I will hook up then follow instructions in the link further back some one posted for me. But I am sure I will have questions, I have no idea what to expect. What would the USB cable be for?

 

[ArloG]

Yeah I dont know if I will have a problem with interference. There is only 1 LOUD pager on 152.600 but I dont know where it is. Doesnt seem to affect anything I listen to. I have a spare 800mhz yagi that I am not really using. It's up on mast but not connected to radio. I first gotta get dongle. It is supposed to arrive later today in mail. Then still waiting on the adapter. Once I get these I will hook up then follow instructions in the link further back some one posted for me. But I am sure I will have questions, I have no idea what to expect. What would the USB cable be for?

Oh man I'm sorry. I for got your radio will plug right into your computer. Others that do use a cable experience a bit of switching supply hash and running the pc on it's battery is about the only way to reduce the noise without a good USB cable.
In time you'll probably be interested in an LNA. Some have built in filtering and some not. Notch filters are out there too.
Just go slow and ask questions.

 

[bobruzzo]

Oh man I'm sorry. I for got your radio will plug right into your computer. Others that do use a cable experience a bit of switching supply hash and running the pc on it's battery is about the only way to reduce the noise without a good USB cable.
In time you'll probably be interested in an LNA. Some have built in filtering and some not. Notch filters are out there too.
Just go slow and ask questions.

I use a desktop for everything, so hopefully there will not be a noise problem. So the software doesnt have an LNA and a Notch filter? Or are the hardware versions better? I'd have to learn how to use those things. I am familiar with filters in music recording but dont know how to apply them to RF. I am hoping the adapter comes in soon this week cause I am wanting to get going with this!

 

[slicerwizard]

Software doesn't deal with the raw RF, so no, LNAs and RF notch filters are not implemented in software. You seem to be very unclear on the concepts.

 

[silberj]

I did order an adapter so I can connect dongle to antenna. I will use my discone. I will start off by trying to get at least an FM broadcast to come in. But I want to mostly monitor the conventional scanner stuff for now. Long term goal is to be able to monitor my local P25 simulcast system because even with having an sds200 I still get simulcast distortion. But I am not sure how well that is gonna work either.

I manage to monitor 3 trunked systems, and many P25 systems using 2 standard dongles and DSDplus +FL. For trunking, DSD uses both dongles, as the system's frequency spread is too wide for just one, but on my scanning configuration where I am just scanning multiple P25 channels that aren't trunked, I only use on dongle with DSD. FMP24 (part of DSD) has a great scanning function where I can set delays and many other settings. I use the other dongle and HDSDR to monitor the approach air traffic at Lousiville International airport.

 

[bobruzzo]

I manage to monitor 3 trunked systems, and many P25 systems using 2 standard dongles and DSDplus +FL. For trunking, DSD uses both dongles, as the system's frequency spread is too wide for just one, but on my scanning configuration where I am just scanning multiple P25 channels that aren't trunked, I only use on dongle with DSD. FMP24 (part of DSD) has a great scanning function where I can set delays and many other settings. I use the other dongle and HDSDR to monitor the approach air traffic at Lousiville International airport.

I am able to monitor a few non simulcast P25 stand alone freqs that various PD's are using, mostly in Southeastern Mass. Including my own towns Police dept. and the freqs are all UHF in the 480mhz area so the signals are decent. I did read you need 2 dongles to monitor a whole system of P25. I am still waiting for my dongle to come in...hopefully tomorrow then I can pull out hair figuring all this out.

 

[bobruzzo]

OK Dongle arrived and I got it set up working with no problem. Was able to tune in to FM music station....then tried a couple PD freqs. I turned on "filter audio" cause it got rid of a little white noise. Adjusted gain to about 40db....not sure where to set this but it seems to be ok. So now what can I do with this thing? I need to figure out next what to do with that other program DSD Plus. I cant get it to do anything. No way to even configure it.

 

[bobruzzo]

With SDR#, scanning multiple frequencies, trunk-tracking, and decoding P25 digital are done using separate add-ins. As suggested, start slowly with simple analog frequency reception and build from there. SDR is true roll-your-own radio reception. You're a Ham, you'll figure it out.

I was able today to get SDR# & DSD Plus working. But I am not sure whats happening....here is a screen shot of it all. I tuned in the control channel of a local NXDN site. Have no clue whats going on in this photo. But is this working the way its supposed to? The audio piped in via "VB Cable" and using computer speakers for audio. I dont know what NXDN is or how to decode because a control channel is all a huge repetition in the black screen window....and the "event log" is showing some stuff. How do you decode anything from a control channel?