In another thread I saw you mention that you live in an apartment that has stucco lined with metal mesh (roof is unlined) and use and inside antenna. And you can still receive R. Nacional de Amazonia from BC reliably? I’m impressed. What kind of antenna are you using? Do you employ any active RFI mitigation?
Well, this is may surprise you: I receive RNA well on any of my three SW radios, two of which are portables using only the whip antennas. If I connect the 23-ft. wire antenna that came with my Sangean ATS-909x portable to the radio's input jack, the signal strength is only slightly better, but the noise increases significantly, so there is no appreciable advantage. The other portable is an old Sony ICF-2002 bought in 1998.
The third SW radio is an Icom R75 tabletop from 1998 requiring an external antenna, for which I use the same 23 ft. of wire. The portables actually sound better than the R75, which has the strange characteristic of making the noise a lot more noticeable. Even the noise reduction feature added by the R75's DSP module accomplishes next to nothing, and setting the NR level too high causes distortion.
By the way, I can sometimes hear RNA on my portable scanner, as its wide frequency range includes the HF bands. Again, this is with just the whip, which is nothing more than a little "rubber duck" antenna. So that makes four radios altogether. I am currently only using the Sangean for shortwave; I bought the scanner for VHF and UHF monitoring. The other radios are now in retirement.
As for RFI mitigation, none of that works in this building. I'm surrounded on all sides by sources, including lots of power lines outside.