[TowerTalk] Grounding on a rock hilltop

[scottw3tx at verizon.net]

I'm working on a friends' station this week, which is on the top of a very
high hill (the hill-top is about 100ft above the terrain for 270 degrees of
azimuth).

Naturally, the hill is solid rock (the tower foundation was blasted).  There
is from no to perhaps 2 inches of soil covering the rock. 

I'm interested in hearing what has worked to improve station grounding in
similar situations.

73, 
Scott W3TX