Mike, KA3JAW, asked, "Do you hear a multicultural station on AM 1710 that also comes in during the day time at about the same signal strength?"
I replied, "I have never heard it during the day. I do hear it occasionally at night (maybe once every two or three weeks). I thought it might be a pirate. If you are hearing it during the day, it is probably a lot closer to you than me."
That exchange started a weeklong quest to figure out what we were hearing.
The only other stations I hear on 1710 are the Springfield (MA) Armory TIS and WQFG689, the Hudson County (NJ) TIS. I usually hear one or both each night, but the mystery station is a little rarer.
For about one week, I monitored 1710 whenever I had the radio on at home and in the Subaru. This is what I discovered:
When the station shows up, it is usually around sunset for 15 to 30 minute appearances. One time, I also heard it very briefly on the car radio at sunrise.
One evening, I was able to receive it very weakly on the directional antenna (a C.Crane Twin Coil Ferrite on a turntable). The signal peaked to the southeast/northwest, approximately 135/315 degrees. There is not much to the southeast... just some small towns in southeastern Connecticut, the eastern tip of Long Island and then the AtlanticOcean. The northwest is more likely the source... Albany, Syracuse, Rochester and Buffalo, NY and Toronto and Hamilton, ON.Mike mentioned that he thought he heard Canada mentioned a few times, so perhaps it is a Canadian station.
The station remains a mystery... maybe a little less mysterious, but still a mystery.