Correct way to calibrate Limesdr


I’m read a lot of topics about calibration and confused. What is the correct way to calibrate device?

andrewback Jan 3
Calibration value caching should not be used any more and IIRC by default it is now disabled. The MCU will perform calibration on-the-fly and the old mechanism which persisted values to a database on the host is likely to be removed at some point in the not too distant future.

After this topic try to use limesuite “Calibration” tab. But DC on tx not removed. Try to remove dc from limesuite with DC corrector and control output with airspy. Result much better, but still does not satisfy me.
Than try to follow recommendations from this wiki page LMS7002Mr3 Calibration Using MCU - Myriad-RF Wiki, but cant upload hex to Limesdr.
After try to read and understand this manual LMS7002M-docs/LMS7002M_Programming_and_Calibration_Guide_v31r05.pdf and I’m want to shoot myself))))))

Can you explain me how to calibrate device? simple manual step by step. or maybe you know another easy way to calibrate it?

Ps Sorry for my bad English.

What are your expectations for the Tx DC level in dBC?

General steps:

  1. Program MCU, it can be programmed at any time. (if using LimeSuite, MCU will be programmed automatically when calibration functions are called)
  2. Configure chip parameters to your desired working conditions (Rx/Tx frequencies, sampling rates, tx/rx antenna paths, gains). Make sure your gain settings are not saturating Rx/Tx, otherwise calibration will give worse results
  3. Execute calibration (press button in GUI, or call LMS_Calibrate function)

Oh, i can’t tell my expectations for the Tx DC level in dBC. Sorry. But i can try to explain you what i want.

Is this level of DC suppression normal for automatic calibration?
If useful digital signal coincides with DC it degrade and can’t be decoded.
SDR console v3 or Gqrx calibrate Limesdr after start program?
Pothos SoapySDR source call LMS_Calibrate function automatically or i need to do it manually?

If you’re trying to show Rx DC level suppresion, then yes, it’s normal like that.
SDR console v3, Gqrx, SoapySDR do calibration automatically