Up to now I didn't find any other purpose of this middle knob.
Headphone is in stereo on my unit with the three knobs on the side.
Not sure if this is really the firmware version? You can see in the 1.15 video, that "iMS" and "EQ" are greyed out (not active), but in the 1.18 video they are white (active). This could make the difference.ArthurSRB hat geschrieben: ↑Do 24. Nov 2022, 18:05 Thanks to these recordings,it can be seen that version 1.18 has a weakened AGC function, which is manifested by muffled noise and a sudden jump in the deviation of the radio station even when the signal level is corrected with the offset option,which is unacceptable !
You can enable/disable iMS/EQ by pressing the tuning knob down for 1-2s. On weak signals I think the sound gets a little bit more "muffled", but also some distortion disappears. I have a place close to some LED lamp which creates some noise in FM band and I can filter it out by activating these two filters.
Thank you for the hint with the "level offset" setting. Did not try this before, but it seems that weaker signals are getting louder then, while strong signals remain at the same loudness levels. So with a higher "level offset" it is a little bit easier for me to identify weak signals, because they have almost the same loudness level. I also didn't see that the unit gets overloaded then on the telescope antenna.