PRCguy has the right answer. Enough about antennas, cables, power supplies, etc. The closer you are to the repeater, the less picket fencing will occur. And yes, the Chinese radios have a problem with it more than the higher end models. But eventually, everyone will run into picket fencing while mobile at some point. He's dead on about null spots. I can move my car just a foot, and have no problems. (As long as I stay in that spot)! Certain parts of town, you will find picket fencing all the time. Some places, you don't hear it. It also pays to be in a repeater that is very high off the ground. Here we have (Say two) repeaters just a mile apart. One is on a 300' building. The other is on a 600' tower. I get way less picket fencing in a certain area with the 600' tower. The 300 footer makes me want to pull my hair out trying to have a QSO. I find it necessary to pull over, find the null spot and finish my QSO. So, the problem is NOT solvable. It is something we all have to accept.