The latest ENIGMA2000 newsletter #EN58 has some great stuff in it regarding the mysterious numbers station that broadcasts short 5F messages daily around 1600 UTC (plus or minus three minutes), in Vietnamese.
ENIGMA2000 notes, on page 3, that their Vietnamese speakers have been unavailable. One is in Viet Nam. Funny they should bring that up. That's where mine is too. There's a big Vietnamese community in SoCal, and so I'll keep at it.
(A post on UDXF mentioned that a different (as in available) Vietnamese speaker has listened to one of the many recordings in existence. They thought the radio announcer's dialect sounded northern, maybe the Hanoi area.)
Page 11 has an excellent research result sent to ENIGMA2000 by a California listener who goes by Token. He's done a lot of grunt work on this one. He's out on the (quiet) desert with good equipment, knowledge of how to use it, and my dream antenna - a rhombic pointed at Asia. I could sort out the Japanese fishery fax in a hurry with one of THOSE puppies up in the air, dominating our entire suburban neighborhood, with poles sunk into neighbor's flower gardens, keeping lightning away from everyone's houses... but that's not important now.
He mentions that a shipping company might not have a lot of reasons to repeat a broadcast 30 times. I tend to agree that, until we get something definitive, it's safest to assume it's some kind of encrypted transmission sent to or from Viet Nam, for the purpose of passing coded information of a highly sensitive nature to an unknown person or persons whose identities are not for public knowledge.
Either that, or someone who listened to Conet once too often.
More when we get it.....
