Notch Filter and antenna ports for RSP2

[Bobman50]

The spec says the AM broadcast MW Notch Filter >30dB is designed for 680-1550 kHz. According to the block diagram the Notch Filter is only valid for antenna port A and B. However port A and B are specified for 1500 kHz - 2 GHz. The Hi Z port which does not have the Notch Filter is specified for 1 kHz - 30MHz. I do not understand this. Please explain. At a U-tube presentation of the RSP2 there is said that the performance is decreased below
1500 kHz for port A and B so it will not meet spec. What specific performance is decreased below 1500 kHz for these ports?
What do I gain and what do I miss when I use the Hi Z port?
I am interested to buy a RSP2 and my main interest is AM broadcasts in the MW and SW bands.

[g1hbe]

The AM notch is designed to stop images from the AM(MW) band popping up in higher bands like SW and VHF. You would use antennas A or B for listening on VHF, so that's where the notch filter is fitted. You wouldn't want to notch the AM band when listening to the AM band via the Hi-z port.
I find the spectrum from VLF to 30 MHz is better (lower noise and fewer images) via the Hi-z port. This port rolls off above 30 MHz, so VHF/UHF is handled via ports A and B.

[Bobman50]

Thanks for the comments. I did missunderstand the function of AM notch. I am used to trimming my notch while listening to broadcasts on USB and manage to get rid of disturbing tones for instance. This may be handled by the software SDRUno if I understand correct.