Spycraft - Melton [170]
The Americans also trained indigenous forces to observe at key positions along the trail and report on North Vietnamese convoys. The observers had radios to “call in” when they saw traffic, but information had value only if the teams understood and reported precisely what they were seeing. “Some of them didn’t know the difference between a truck or jeep or trailer,” Jameson noted. “We needed a better way for them to communicate.” To compensate for the language problem, the reconnaissance team units were issued the Elephant Transmitter with buttons that featured icons depicting a man, bicycle, elephant, truck, troop transport, or tank. The observer punched the icon matching the vehicle’s shape to record traffic types and numbers.
The techs also tapped North Vietnamese communications wherever lines or transmissions were accessible. One program tapped transmission wires, recorded conversations, and transmitted to a hidden “repeater” that was actually the first of a string of relays that stretched across Laos to a safe listening post in Thailand. In essence, the system functioned like a modern cell phone network, with the signal bouncing from one cell, or repeater, to another, until reaching the listening post. “The biggest problem with this operation wasn’t the transmission,” explained Jameson, “it was finding places to hide the relays.”
The tapping equipment used a mixture of commercial and Agency audio devices and batteries reconfigured in the field for the operation. Some of these were concealed in wooden telephone poles. In a typical operation, a two-man team of Montagnards would be inserted by helicopter to within walking distance of the target. It was, at best, a difficult operation, the team carrying a pole filled with batteries and transmitters through miles of hostile territory. Once at the target, they climbed the pole, tied down the telephone line, substituted the original pole with the TSD replacement, and reattached the line. When an operation went smoothly, the listening post immediately received a stream of North Vietnamese conversation. “We were getting an awful lot of intelligence on the movement of supply trains coming down along the Ho Chi Minh Trail from North Vietnam to the south,” said Jameson. “That information allowed us to target supply convoys and understand something of their order of battle plan in the South. Trucks loaded with 7.2 [rifle] ammo compared to truckloads of mortar rounds indicated preparations for different types of engagements.”
The development of electronic and high-frequency signal and homing devices for clandestine operations may have been TSD’s most significant contribution of the Vietnam and Laotian conflicts. Historically fires lit on top of high places and hilltops served as beacons for navigation and path-finding and alerts of approaching enemy forces. Paul Revere’s midnight ride that warned patriots of the advancing British army began with a beacon of light in a church steeple.
By the 1960s, ground-based radio direction-finding equipment became a primary navigation aid to “mark” a position for guiding aircraft or a ground party to a specific location. The techs installed hundreds of HRT-2c aircraft beacons at defensive and logistic sites throughout Laos to enable pilots to find locations for airdrops, landings, or close support.
Although the HRT-2c was compatible with automatic direction-finder systems already incorporated into all CIA, military, and commercial aircraft, it presented problems in placement and maintenance. Because each beacon required an antenna at least fourteen feet tall with a ground