As far as I can tell, the all-PSA AM 1640 that I get (just barely) where I live is in Bedford MA. I live in Arlington, just east of the Lexington line and just north of Route 2. I think I am roughly 10 to 12 miles southeast of Bedford. The signal is barely readable here, but I think the call sign contains the numbers 298. There were frequent mentions of phone numbers in the 781-275 exchange, for which a Google search came up with Lexington MA, but I heard Bedford often enough that I still think Bedford is the correct town. Bedford is adjacent to Lexington. There was also something in what must have been a legal ID that mentioned that the station was operating under authority of the FCC. Another message said that the messages being broadcast (apparently in an endless loop) had been updated on September 2. As I write this, it is 4:20PM EDT on Saturday September 4. 2010.