SDR# updated to revision 1400 & SDR Touch updated to V2.6

The popular SDR# software which is often used together with RTL-SDR dongles has recently been updated to revision 1400. This new revision brings an interesting new feature which automatically estimates and displays the peak, floor and signal to noise ratio (SNR) values of the currently tuned bandwidth. Watching the SNR metric is very useful when tuning the RF gain settings, as best reception is obtained when the SNR value is maximised. The author also writes that there have been several radical changes to the code that leverage the latest .Net 4.6 framework which should improve the signal processing quality, CPU usage, user experience and hardware support. The changelog is pasted below:

Enhanced the Center tuning mode and extended it for RTL-SDR;
Enhanced the spectrum display;
Changed the frequency labelling to use multiples of 2.5/5/10 or frequency steps;
Added Peak, Floor and SNR estimation for the selection;
Enhanced the defaults for better user experience;

We note that some plugins may break with this update so be sure to make a backup if upgrading. Vasili, one of the most active SDR# plugin programmers has updated most of his plugins to work on this new version now.

Revision 1400 of SDR# with SNR estimation.
Revision 1400 of SDR# with SNR estimation.

In addition to this update, over on the Android OS the popular mobile app SDRTouch has been updated to version 2.6. This new version brings the following features and improvements:

  • Baseband recording and file playback
  • Direct sampling support for full-band receivers
  • Improved SSB image rejection
  • Fixed tuning step
  • Manual filter bandwidth
  • Improved accessibility
  • Bug fixes
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Hello, I have a problem with the latest version (sdr# 1423) It does not recognize my RTL SDR usb device. I use 2 different sticks, but none of them works. When starting the previous version, they work fine. What could be the problem?


Did you run install-rtlsdr.bat?


Is it possible to operate gr-gsm with a data rate lower than 1MSps? I am trying to run it on a raspberry pi B, it starts parsing pakets, then showing overflow 00000. The same code and rtl-sdr is working fine on a PC.


I’m scratching my head now. How does SDR# , relate to running gnuradio with a gr-gsm module on a Raspberry PI!. I would read the publicly GSM documentation and decide for myself if what I was trying to achieve could function with less than 1Msps, or read though the source code to gr-gsm – use the source Luke, use the source.


There is even a dedicated mailing list (see: ), why ask here on the comments of an Article that has nothing to do with GSM or gnuradio or the Raspberry Pi .I’m still laughing.

Don't Be a Dick

Rude as ever I see. You’re bad attitude and continued rudeness is enough to keep me from buying your piece of crap SDR.


“your” ? nothing to do with me, SDR# is free as far as I know ?


There are at least two different people who post here with the handle “Truth”, that I can see, so maybe that has you confused. I post here a good bit, and I usually only post things that help people, not insult people. But I try and keep the universe balanced, so for everything helpful that I post, if I can tease someone for doing something silly I will. As for you not buying what I’m selling, I don’t sell anything. Maybe someone else who uses this handle does, I don’t know or care. I personally find you insulting without actually adding anything of value to a conversation.


Does it do 8.33 steps on airband yet?


You mean the 8.33 plugin at ?

Kevin McCormick

This version seem super buggy. My TCXO dongle was showing 10 Khz off.

Anonymous Coward

Is it me or is ADSB# missing from this release? If it is missing, Where can I get it?


I looked in an old SDRsharp folder (1361) and the date on that file (ADSBSharp.exe) is 2013-01-27, it has not changed, or been updated, in a very long time. At a guess it was just deleted because it was not better than anything else – maybe use modesdeco2 instead if you have a rtlsdr stick –


truth how do you run modesdeco2? I cant figure it out. i have a windows machine.


I don’t know if this is the right way or not, but I run something like the following command:
modesdeco2 –gain 49.6 –freq-correction 44 –location 12.345:-6.789 –web 8088 –beast 10003
(adjust location to your latitude and longitude)

And then I open a web browser on

There is probably far far more that can be done with it, if you read through the whole thread and look at the available command line options (modesdeco2 –help).

Buford T. Justice

1401 was just released. It now has a SNR meter.


nice, but not working under mono, I have been installed the alpha mono
mono -V
Mono JIT compiler version 4.2.1 (Stable Tue Oct 6 14:40:19 UTC 2015)
Copyright (C) 2002-2014 Novell, Inc, Xamarin Inc and Contributors.
TLS: __thread
SIGSEGV: altstack
Notifications: epoll
Architecture: amd64
Disabled: none
Misc: softdebug
LLVM: supported, not enabled.
GC: sgen

mono SDRSharp.exe get the error :
[ERROR] FATAL UNHANDLED EXCEPTION: System.TypeInitializationException: The type initializer for ‘PortAudioSharp.PortAudioAPI’ threw an exception. —> System.DllNotFoundException: portaudio
at (wrapper managed-to-native) PortAudioSharp.PortAudioAPI:Pa_Initialize ()
at PortAudioSharp.PortAudioAPI..cctor () in :line 0
— End of inner exception stack trace —
at SDRSharp.Radio.PortAudio.AudioDevice.GetDevices (DeviceDirection direction) in :line 0
at SDRSharp.MainForm.InitializeGUI () in :line 0
at SDRSharp.MainForm..ctor () in :line 0
at (wrapper remoting-invoke-with-check) SDRSharp.MainForm:.ctor ()
at SDRSharp.Program.Main () in :line 0


You have an clear error message – “DllNotFoundException: portaudio”, and if you search around Mono forums, you will eventually find the correct solution.

Under ARM Linux I do the following, if you are x86/x64 you will need to change the paths to where you have your shared objects installed:
$ cd sdrsharp-x86-r1400
$ ../
$ cat ../
#!/bin/sh —

rm *.so
ln -s /usr/local/lib/
ln -s /usr/local/lib/
ln -s /usr/lib/arm-linux-gnueabihf/
ln -s /usr/lib/arm-linux-gnueabihf/

ls *.dll *.exe |
while read line
# /opt/mono/bin/mono –llvm –optimize=all “${line}”
/opt/mono/bin/mono –aot=full –optimize=all “${line}”

if [ ! -f SDRSharp.exe.config ]; then
echo Making SDRSharp.exe.config, none exists
mv SDRSharp.exe.Config SDRSharp.exe.config

I launch SDR# with
$ mono –optimize=aot SDRSharp.exe

And if you are x86/x64 you will get better performance if you compile llvm into your mono, and use “llvm” instead of “aot”.

P.S. Do not run SDR# under ARM, unless you are totally insane.


Oh and do not expect anywhere near the performance, and expect lots of glitches, Mono although good is not perfect (yet).

Simon Franklin

Are you taking the piss out of me…

After all the hoopla about revisions and upgrades Airspy with SDR# still can’t decode a standard FM using a standard USB 2.0 connection to a core i7 laptop.

Stuttering & awkwardly buffered audio. What a rip off.

Airspy is 10x better on paper than in real life.

What a disappointment.

When you promise a device…make sure it actually works on a real world computer.

Howard long and the Funcube dongle rule…still.


No where in the Article do I see mention of the Airspy. But have you checked on that your CPU scores at least 3500 and that the RAM on your PC can handle at least (40+80+80)200+MB/sec, and finally that the chipset on your USB ports is top notch. Basically can you run 8x RTLSDR devices at 2.4MSPS on your PC with no drops. The Airspy transfers 40MB/sec at 10MSPS (an RTLSDR at 2.4MSPS transfers 4.8MB/sec). And a Funcube dongle pro transfers 384KB/sec and the plus doubles this. If your PC is low spec then the FCD is the way to go.


TBH, you should have some USB problems in your PC. Most people moan about the products when they have no clue how to fix their own problems. FYI. No amount of performance can make a 10MHz SDR work if the USB controller refuses to suck the data at full speed. Airspy is a modern radio that needs modern hardware and it outperforms all the > 30MHz radios I own: SDRs (Funcube+, HackRF, BladeRF, SDRPlay and even the B210) and Analog (BCD396XT, FT-857, FT60). Many people have had the same feedback over time, so your problem definitely a “User Error” as they say.
My “Radio PC” is an i7 4770K with 32GB RAM and 1GB SSD. I run two Airspy units on the UHF bands and they work even better with the latest version. I also run many decoders and control software.

simon Franklin

Hold on a minute…
I thought that it would somehow turn into my problem and be a user operated error…again me being the problem.
Well, let’s look at my situation, a normal user like so many others. No 32Gb of RAM here.
I ran the sdr# benchmark and my laptop returned the 10Msps+ consistently. Good news.
But when I tried to operate in any mode at 10Msps I get stuttering and unusable performance. er.
Q1: Why does the benchmark offer passable results when the device is actually unusable in that mode: ie:10Msps.
I then switch to 2.5Msps and get interference bars across the pass-band.
If I remember this was due to be resolved…
The Sales spiel from Airspy didn’t mention a minimum spec of USB3.0 to operate the device.
So I have a powerful laptop Corei7- albeit USB2.0 but still cannot use the Airspy because my laptop isn’t powerful enough.
Operator error or misleading minimum requirements…you judge.
My Airpsy sits on the bench unused because it is my fault that I don’t have USB3.0 yet.
Cheers guys, all the best.


It sounds like your USB is probably OK, and that your CPU is old (below 3500) or possibly your RAM is too slow.

It sounds like your machine is not powerful enough. It is a bit like buying a Ferrari engine and sticking in a Lada chassis, it might work, but probably not very well.

Buford T. Justice

Also SDR# runs on Linux with Mono 4.0.4 and newer.


It could do that with every version since they migrated to 4.6. 1361 was the last version that worked on the now virus/spyware riddled, bot owned XP (R.I.P.) OS and also supported legacy extio plugins, so any version after that could run on OSX/Linux with Mono 4.0.4 (or later). Mono still has some UI flaws, but it is getting faster and better. I’ve tried it with 4.3.0, and there are still many GUI glitches.

Buford T. Justice

Mono is working just fine for me with my RTL-SDR with built-in upconverter. Ubuntu MATE 14.04 LTS is nice. I am not missing running SDR# or anything else in Windows 🙂