The radio facility is

where you turn south on a very rough and rocky road. See the road that is taking off just to the left side of this pic? That is the road you want. If you get closer to the radio facility, you'll need to backtrack to get this road. Then it is a bit over two miles to a junction with a road that turns east and is a decent road for about 3 miles until it turns south into a canyon where the road will test your vehicle a bit. 5-31-08