Radio Habana Cuba and 6 radios of interest

I went out on the patio about 1405 UTC in Palmyra, Virginia with the purpose of comparing some superhet phase lock loop radios, specifically the Grundig G4000A Kaito KA1101 Sangean ATS-909 Tecsun PL-660 Tecsun PL-990 I typically start processes like this by doing a quick band scan with my Qodosen DX-286 because it's fast, sensitive, and accurate. I want to see what's on the air. Today I did the scan, using the modest telescopic antenna on the DX-286 and the first station that was stored was a somewhat weak station on 6000 kHz. It wasn't strong enough to pick up the language but clearly people were talking. So I grabbed my Sangean ATS-909 and there was nothing. On the PL-660 and PL-990 nothing. Was this some spurious signal? I plugged in my WUP antenna (20 feet wire up a tree) and I heard something faint on the PL-990. Yes, it was a real station. After time, the signal got stronger, and with the external antenna, all the radios got it. I could tell the program was in Spanish, so I'm calling it Radio Habana Cubs. Interestingly, the previous owner of my Sangean ATS-909 had programmed 6000 kHz on a memory page labeled "Cuba." The signal improved until it abruptly shut down around 14:22. Clearly, the DX-286 outclassed the other radios in this comparison.