Hi Herb and Erik

I think I can provide hints what Herb is fighting. I have a day fully booked but I have 1 hour free form now and will do my testing and then comment

Kind regards

Kurt

?

On Tue, Aug 4, 2020 at 08:57 AM, Erik Kaashoek wrote:

New FW released
version v1.0-49

Changes:
- Corrected a rounding error in the level calibration causing up to 1dB level error

Due to a data format change you will lose your configuration information. If you have made any changes you should redoc these after updating.
Both high and low mode level calibration should be re-done using either the built-in calibration source or an external known level signal.
The calibration error off factory should be less then 2dB so after this FW update your levels should be within 2dB without calibration.

Erik,
? Prior to the version 1.0-49 FW update a level calibration on my v0.3 tinySA would set leveloffset low to '0' which gave me a measurement error of < 1dB across the board measured against an external signal source.? With v1.0-49 a level calibration is now setting leveloffset low to '1.7' and my measurements against an external signal source are off by about that amount.? I have to manually set 'leveloff low 0' to regain my <1dB accuracy.? This using the new correction table.

?The v0.2 beta unit has benefited from the FW update. Level calibration sets 'leveloffset low' to a value of -0.7 which resulted in??a measurement error of < 1dB across the board measured against an external signal source. This using the new correction table.

?FW updates including 'clearconfig 1234' set 'leveloffset low' to 100 and measurements at some frequencies in this uncalibrated state exceeded 2 dB at the limits of the measurement range.? In this case a level calibration is necessary and then possibly some fudging of the leveloffset low value.

?In the end, I used the leveloffset low value the level calibration calculated for my beta unit, but had to manually restore my previous leveoffset low value for the production unit.

- Herb