Using Airspy R2 .... turning on bias tee problem to collect and average H1

[Stephen Arbogast]

I have been  trying  to  use my AirSpy R2   on  both  Ubuntu and Windows and  I am running  into a problem  turning on  bias_t .  Here is  a  summary...

Ubuntu 24.04.2 LTS,, latest  GNU Radio Companion flow graph using SOAPY source, cannot turn on bias_t

Windows 11, GNU Radio Companion flow graph using  SOAPY source, cannot turn on bias_t

Windows 11, GNU Radio Companion flow graph using  OSMOCOM source.... I can turn on bias_t 

I have a simple program  in Python to test  turning on bias_t   using  soapy.Device  on Ubuntu  does not work.   

Below  is  a  screen shot of osmocom source working  on Windows 11....

Wondering if anyone else has  experienced this?

I am thinking   the  driver  for soapy  does not implement this.

[Richard Squirrel]

Hi Stephen,

I just received an AirSpy R2 and an AirSpy mini.

Like you, I want to run them under Linux, in my case using a 64-bit bunsenLabs (12 Boron) https://www.bunsenlabs.org/

My goal is to use ezRa with the Soapy SDR drivers.
I'll probably start with a basic Python script and check the bias-tee first.

Perhaps you should take a look at this fork, which seemed to have more advanced support:

https://github.com/ast/SoapyAirspy

More settings are available:
soapy=0,driver=airspy,biastee=true|false,gains=linearity|sensitivity|manual

I might have time to test this during my week off.
I'll keep an eye on your messages!
Thanks.

Richard

[Richard Squirrel]

Sorry, it seems that biastee support was put in the main driver a long time ago:

https://github.com/pothosware/SoapyAirspy/issues/4

https://github.com/cjcliffe/CubicSDR/issues/402

Richard

[Stephen Arbogast]

Code that Ted Cline wrote works....  

#create device instance

#args can be user defined or from the enumeration result
args = dict(driver="airspy")

sdr = SoapySDR.Device(args)

#Turn on bias_tee

result = sdr.writeSetting("biastee", "true")    # Airspy

[Stephen Arbogast]

I plan  to  add  more features  in the  future   such as those  in ezCol.py  Since I don't yet  have  az/el  control of  my small Discovery Dish  it is  very  hard to  collect cal samples.  My  inspiration  has  been  Ted Cline.  I invite  constructive  criticism...... 

Stephen

On Tuesday, May 27, 2025 at 3:55:42 PM UTC-6 Stephen Arbogast wrote:

A GNU Radio flow graph, Windows 11, GNU Radio 3.10.10.0 (Python 3.11.9)

[Stephen Arbogast]

If  any interest  I will  put  my iterations  on Github....and consider  improvements...  let me know.

[Stephen Arbogast]

On Tuesday, May 27, 2025 at 3:55:42 PM UTC-6 Stephen Arbogast wrote:

A GNU Radio flow graph, Windows 11, GNU Radio 3.10.10.0 (Python 3.11.9)

On Monday, May 26, 2025 at 3:24:41 PM UTC-6 Stephen Arbogast wrote: