Airspy HF+ R5.0.0 Firmware Updates Available

[RobRich]

Firmware updates are available for the Airspy HF+ series of SDRs.

https://airspy.com/airspy-hf-discovery/ (firmware info near bottom of page)
https://airspy.com/downloads/airspy-hf-flash-2024-10-04_5.0.0.zip (latest firmware as of this post)
https://airspy.com/downloads/hfplus_changelog.txt

Recent changes:

R5.0.0 - 2024-10-04

Improved gain distribution and AGC/ATT/Preamp controls for all the bands.

Description and discussion:

In this build, the RF ATT is controlled by a separate AGC loop even when you disable the AGC option. Instead, the Baseband AGC loop before the ADC handles the user ATT steps along with the different gain stages. The overall gain is stable thanks to another loop that handles the gain compensation in digital (48 bit scaling.)

This new implementation tracks the signal changes better than the plain old manual ATT, while assuring the best linearity/sensitivity balance even when the settings are completely off. The noise floor can be set very low, if needed.

https://groups.io/g/airspy/topic/new_experimental_gain/108814053

There is a hfplus_ppb.exe utility in the download archive for manually reading and setting the frequency calibration offset value. Details here:

https://gist.github.com/jj1bdx/ce9eb3bd7320eed76396669a25f27e29

The flash script should save and restore the value, though note it will not do so if using Windows under VirtualBox due to needing to run the flash script twice. It is a good idea to record the value anyway. Airspy.US should have original calibrations on file for Airspy HF+ models purchased there as well, though there can be drift over time, so YMMV.  More details:

https://gist.github.com/jj1bdx/ce9eb3bd7320eed76396669a25f27e29
https://groups.io/g/airspy/topic/airspy_hf_calibration/31910863

On a related note, the current SDRSharp 1921-next beta release build has been updated as well.

https://airspy.com/downloads/sdrsharp-x86-next.zip

Previous HFU firmware announcement thread:

https://www.hfunderground.com/board/index.php/topic,127020.html

[osiris]

Wow! Huge difference. Thanks for the post!

[RobRich]

The current SDRSharp 1921 beta now includes the ability to set bandwidth when customizing the IF and AF noise filters.

https://airspy.com/download/