m400 is a great option for in the valley..i lived in a valley for 7 years was told the same only i didnt listen..lol .only better option might be to put up a flatside beamThe Workman Star Duster was my first base antenna getting back into CB again and ran it for years with success and great SWR across the band until water got in it and it froze and split. Then I went to the Sirio Star Duster which I'm running now and it works great for this Stinking Valley. My heart yurns for the Mountain Top ! LOL