I've been DXing the mediumwave band off and on now for over 30 years, mostly from Toronto and Kingston, Ontario. I've logged close to 800 stations in that time. But there are still ten frequencies on which I've only ever logged one station. Ignoring the four that are in the extended 1610-1700 kHz band segment, there are still six frequencies on which I've only heard one station in over 30 years.
At least, there were six. Now there are five, because last night I finally logged my second station on 1180 kHz.
Some time this summer I began hearing a faint Spanish language station on 1180 under WHAM. I spent several hours over several nights trying to get an ID out of it, but no success. I figured that it was probably the Radio Marti outlet in Marathon, FL, which broadcasts at 100 kW. For all I know maybe it was Radio Marti. But it was never strong enough to ID under the interference from WHAM.
Last night, a bit before 2 a.m., I heard a Spanish station on 1180 again, and it was coming in strongly enough that I figured there would be a chance to ID it. So I sat listening to it until 3:15 (05:55 - 07:15 UTC). A bit after 3 a.m, it was coming in strongly enough that I was able to make out a bit of what they were saying, and I was surprised to hear "desde Habana, Cuba" and something that sounded like "Voices of the Revolution" (in Spanish). I looked it up in the 2008 WRTH Handbook and saw that there is a 50 kW outlet of Radio Rebelde on 1180. I then turned on another radio and went to 5025 kHz, where Radio Rebelde is usually audible, and discovered that it was exactly the same program. So that clinched it.
Funny thing is that there was actually a third station also coming in on 1180. WHAM was carrying Coast to Coast AM, and there was a second English language station carrying some other talk show. I never got an ID on that one, but I was amused that after 30+ years of only one station on 1180, I was hearing two new ones at the same time.
I logged this on my little Kaito KA1103. After IDing the station, I took out my ultralight Sony SRF-59 and tuned it to 1180. And there it was, Radio Rebelde, coming in just as strongly as on the Kaito 1103. Amazing, to hear a Cuban station in Canada on a tiny pocket AM radio. I think those ultralight enthusiasts are on to something.