SDRAngel Rx & Tx


Max temperature, measured with Lime Suite was 40 C (20 min AM TX)
(On longer RX session temp goes 37-38C)
But my Lime have cooler on two major chips and box is die cast Al
with internal and external active fan cooling & some members here are
joking that my setup is about to fly away :smiley:


Ubuntu 17.04 & SDRAngel ?
Anyone managed that, yet?
If yes, small “how to” much appreciated…
Already have Lime Suite and Cubic SDR running on Ubuntu 17.04


Oh, around 40ºC with active cooling. I’m just thinking of installing a heatsink.



I’m afraid the buffering is not going to change a lot. With standard PCs and not real time OSes you do need a lot of buffering to absorb the effective rate changes on the USB bus and the CPU. While it can overall sustain the rate it is not at all regular in the details. If you want to reduce buffering and thus latency you have to use a complete different setup with FPGAs and direct access to the data bus of the LMS7002. I think all Tx SDR software that run on commodity hardware and desktop type OSes face this problem or they lie to you.

Another point: I am confident on my dot and dashes but if you use large sampling rates like the maximum of 30 MS/s as I saw on some screenshots (that was Rx and I am already amazed that it works) then packet drops can occur which completely ruins the code you are trying to send. If it was voice you would notice a lot of hickups. Bear in mind that you need such high rates only if your baseband signal requires it which would be the case if you were trying to send WiFi signals for example and SDRangel does not do that. At its very maximum 13.5 MS/s would be required to send an ATV signal at 30 FPS 625 lines and 720 pixels per line.

The Lime has the great feature of hardware upsampling up to 32 times so you don’t need to push it hard on the sampling rate on the software side to get a clean signal. I usually never go above ~5MS/s. I noticed on the Rx side that you cannot get lower than 2.8 MS/s without having libusb warning messages so around 3 MS/s would be fine for most usages.

BTW my Lime is stable at ~50C without active cooling. I mean just heatsinks and an aluminium case, no fans.

Best regards,


Tnx for clarification…
I am curious are you running your SDRAngel SW on Win or Linux and which one?



I have run it successfully on:

  • Lubuntu 16.04.2 - Gigabyte P37 laptop Intel i7 5700HQ - 2.7 / 3.5 GHz
  • Windows 7 Pro - Dell Latitude E6540 Intel I7 4810MQ - 2.8 / 3.8 GHz
  • Windows 8.1 - Pipo X8 - Intel Z3736F - 1.33 / 2.16 GHz
  • Lubuntu 16.04.2 - Udoo x86 Ultra - Intel N3710 - 1.6 / 2.54 GHz

No success on lighter hardware like RPi3 on Raspbian. I couldn’t try with openSUSE ARM64 because OpenGL does not install successfully by default. openSUSE performs largely better than Raspbian in a server configuration.

Best regards,

LimeSDR Operates with LattePanda Win10 64-Bit with SDRAngel

Thank you :slight_smile:

I am able to run on Win 10 home, i3 1,7 GHz, 4 GB RAM
but so far
no luck on
ubuntu 17.04, i7 2,5 GHz, 8 GB RAM (one year old notebook PC)


Apparently Freeman who is registered to this forum has managed it:

BTW, he’s the OM running at the blazing speed of 30 MS/s :slight_smile:

Also I am running a CW beacon in WFM 125 kHz wide (50 kHz deviation) at 175 kS/s in the baseband and I can tell you the dots and dashes are perfect. Software upsampling by 16 makes a 2.8 MS/s rate at the input to the Lime and ~8.4 MB/s on the USB link as reported by the Lime. The hardware interpolator upsamples by 8 so this makes 22.4 MS/s at the DAC with the 5 MHz (lowest) bandwidth hardware filter and 200 kHz hardware FIR filter. The output is very clean.

Although the maths are simple adding the actual DAC (ADC on Rx side) sample rate to the GUI may better catch attention. This will probably be part of the next v3.5.1

Brgds, 73,


@n5fpp do you mind to share how you managed SDRAngel on ubuntu 17.04 for dummies :wink:


Getting SDRangel running under Ubuntu 17.04 was pretty easy for me. I simply did a clone of the github repository, ignored the, did a ‘mkdir build; cd build; cmake …’ I noticed I was missing a couple dependencies. I then read the and googled where to find and installed the dependencies I was missing. I am running the latest LimeSuite from github. Honestly it was pretty straight forward.

I haven’t read the rest of this thread, but if there is an issue with running at 30Msps I’m surprised. I do find I have to run at a hardware and software decimation rate of 4:4 to get any decent performance and not to drop packets. Since I have gqrx running at 60Msps, I was expecting SDRangel to do the same.

In case anyone is curious, I am running Ubuntu 17.04 on a 6 core (12 logical) i7 with 32GB RAM. I did run into problems with my built-in USB 3 ports, but installing a recommended pcie card solved that problem. I don’t remember the brand or model of the card - it’s in another thread that I initiated.

I should say I really like some of the ideas that are in SDRangle. Since I run Ubuntu, I typically only use gqrx or pihpsdr when using my LimeSDR boards. Having an app that is as flexible as SDRangle is really nice. I am already contemplating adding support for decoding AX.25, PSK, WSPR and adding support for DX spotting, scanning, and bookmarking. The plug-in support is really exceptional.

I have chatted with Edouard over email about adding a different UI presentation. I’d like to see something more akin to a light pihpsdr style interface that can fit on a RaspberryPi3, Odroid XU4, or even a future zynq-ultrascale board (which has 64bit and graphics support). I’d like the interface to fit on various sized touch displays (5", 7", 10", etc.). This app would be a separate app from SDRangle, but would be built on the same code base, just with a different QT front-end.

-Freeman, N5FPP


Thank You


Feature request!
A pipe from receive at one frequency to transmit at another (within limits). I was looking to use an audio device as a source file for modulation. It wants a raw audio extension.

Is there a way to output the audio to fldigi or some other such app? For fsk or psk?

This is still one of the best behaved interfaces to the LimeSDR. I am working to get all of the other ones running but this one worked from the start with minimum effort. I think I will study this code to see why it works so well.


what of the missing libs are must have :slight_smile:

SW is running, Lime is detected, but freezing after running rx…


Djani, it may not be freezing - I got no apparent response with initial settings that the LimeSDR receiver used. Make sure you have the hardware and software decimation set appropriately. For “normal” use I have mine set to 4: 4, or 2:4.

Most of the libraries you are missing are for devices. You don’t need them unless you have a device you want to use. The libcm256cc and libnanomsg I either googled for the package to install and did an ‘sudo apt install …’, or for the github repo for them and built and install them manually.

-Freeman, N5FPP


I get freezing of the stream when changing frequency or bandwidth sometimes, randomly. I have to exit the program and restart. Sometimes I have to unplug the Lime and replug it in.
Another thing I just noticed is if I set the frequency to 30.000 MHz I get a washed out spectrum but if I set it to 30.600 MHz I see all of the signals. I can then NCO into this and demod those signals. This is a LimeSDR problem and not sdrangle. I see this in LimeSuiteGUI too.
I find the LimeSDR to be a very buggy bit of kit. I believe many of the bugs will be worked out though.


More / less working now :smile:
Even CW on TX is fair… but do not touch gain :stuck_out_tongue:

Thank You All, for assistance…

Must take small video to celebrate :wink:


@9a4db Djani,

Check the mic audio on that application, too, and video that so we can see if there’s been any improvement since May - thanks in advance for that.

73 de Marty, KN0CK


Sure Marty :wink:
BTW my impression from today is that with some other TRX backup and antenna switching
QRP CW QSO may be possible even now… today my CW went over SSB module and some
spurious (two - one carrier bellow and one mirror CW above main freq) are present within 8 MHz
near bandwith on 432 MHz. Monitored on SDRPlay RSP1 & CubicSDR.
My Agillent test set is on mainland, so can not measure with accuracy but both approx 30-40 dB bellow
main signal.



Back in mid to late May CW and SSB was functioning, but the results I was getting was that the CW was not correct (dots and dashes were not following conventional Morse Code) and that the SSB audio in USB and LSB was very distorted and almost seemed robtic no matter how I adjusted the gain or the sampling rate. So I’m interested in knowing now - from independent sources - if there’s been any improvement since that time (back in May). Post video results of CW and U/LSB audio if possible.

73 de Marty, KN0CK


The same is on my Win 10 notebook.
But, today CW on ubuntnu17.04 was ok, even on higher speed.
Any adjustment for example PA gain and proper CW is gone…
Pls allow me couple of days for video… limited on equipment here :wink: