Courtesy of Des Ball at the ANU here is the Burmese crossed-loop HF/VHF DF system located about 500 metres up the Mekong from Ban Sop Ruak (the so-called “golden triangle”). It is presumably for tracking the radio communications of vessels moving up and down the Mekong, but can be used for locating any HF or VHF transmissions in northwestern Laos and northern Thailand as well as in northeastern Burma.