Flat ground yes but that elevation profile you show above is far from flat. You have deviations of more than 300m which is over 1000 feet. From any two peaks I say yes but from a distant valley in that profile I say no it won't happen reliably at all. If you want flat ground try in the western plains area like Kansas. LOL I don't care how quiet it is or how good your radio is you won't do 30 miles mobile to mobile here with stock 4 watts. Just far to much terrain in the way for that to happen unless both were at a peak and were stationary. This is an elevation profile from a buddies place into a town he talks too. He has a 350 foot rise at about 3 miles out. Not a good situation. Again.......it depends on the terrain whether 4 watts mobile-mobile will make it. I know some places around here where 12 watts on SSB and a four element beam would be hard pressed to make 30-40 miles on a good day. Receiver sensitivity had nothing to do with it. Good amateur gear with decent preamps were used. There is simply no path due to terrain.
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