This fits my post that I just posted to the main link earlier today. I worked at the mobile Tropo site just a little south of the trim pads you're talking about. A few months before I left, which was in May of 1969, I was sent to work night shift back out there. What I saw was that all the vegetation was gone and at night I could clearly see the lights from the bomb dump and the lights around the trim pads. I never knew what they used and quite honestly didn't think much about it. Now I know. thanks