I was an F-105 engine mechanic who worked on the Trim Pad and Test Cell at Takhli from Oct 67 - Apr 68. Both locations were at the north end of the runway and had been cleared of all vegetation. I don't how they cleared it, but there was definitely no vegetation or trees of any kind. I somehow picked up a muscle disease called Polymyositis out of that tour. There is no cure for it. Have all same symptoms as many Agent Orange diseases, but since I had no in- country Vietnam orders,VA says I'm not covered under Agent Orange program.