2 years ago, this was reported as a USN tracking freq - via the UDXF Yahoo group. What was being tracked I have no idea A dead giveaway is the use of a single word callsign or 2, 3 phonetic letters (3 letter calls are often referred to as trigraphs) as a callsign with net-sounding commands and/or locations. Without knowing what you heard it's not possible to dig further 73 Mike