A military telephone call originating in Chiangmai goes by wire to the airport station, then is converted into a radio impulse which is "shot" to a similar station at Koka, where the impulse is amplified and "shot" again to another station further south. The procedure continues until the call reaches its destination.

The Thai Army, the Border Patrol Police, and the CIA can thus phone up their counterparts anywhere in Thailand--and Indochina as well--on a system independent of the civil telephone lines.

About 40 miles west of Chiangmai a Thai contractor is currently building an access road to the slopes of Intranon Mountain, one of Thailand's highest peaks. A radar station is to be built near the summit. The US Embassy spokesman claims that it will be a Thai station and that he was therefore unable to comment on it.

But according to a source in Chiangmai, the station will be built and manned by the Americans. It will be a type of aircraft surveillance system, its location affording a radar "view" throughout the region with only two blind sports--one behind a slightly higher mountain in Burma and another behind Chiang Dao Mountain in Thailand.

Despite nearly 250 American soldiers stationed in the North, the American manage to maintain a low profile in Chiangmai. The city, one of Thailand's foremost holiday spots, has thus escaped the shabby Americanization that has struck so many cities of the Northeast.

The Pentagon, appearing to realize that American soldiers at play make poor ambassadors of goodwill, has encouraged Gls stationed at Koka to stay there during their off-duty hours.