TBS 5925 Maximum SNR at 20db?

Hi everyone, a quick question!
What is the maximum SNR that can be shown using TBS 5925? I have the card running on my Enigma2 receiver and I see that the reading stops at 20db while on my windows PC it can go above 22db on the same frequency! So why is there a limitation on db for Enigma2 or is it something else involved? Theoritically there should be no max reading in db!
What is the maximum SNR that can be shown using TBS 5925? I have the card running on my Enigma2 receiver and I see that the reading stops at 20db while on my windows PC it can go above 22db on the same frequency! So why is there a limitation on db for Enigma2 or is it something else involved? Theoritically there should be no max reading in db!