This problem began three days ago. While moving, I have substantial 'flutter' when in motion to three VHF repeaters which are all mounted on the same tower about 12 miles to the NE from the farthest point in my commute. It is to the extent that the signal from the repeater is often unreadable. I will stress that this is a completely new problem, and also stress that it is only when I am in motion. Here is the outline of the problem: --It only occurs on 2m. I can use 70cm repeaters on the same tower without issue. --It occurs on both of the VHF capable radios installed in the car (with two separate antennas). If I monitor a repeater with both at the same time, the flutter is simultaneous. --It only occurs on receive. Report of my TX audio from others on the repeater indicate that it is pristine. I have taken several steps to eliminate various things as the cause, and I am stumped. Here is what I have done so far: --Connected an antenna analyzer and determined that SWR was <1.5:1 across the 2m band. --Inspected the connectors and coax from the radios to the antennas. --Inspected the antennas themselves. --Swapped out one of the antennas for another dual band mobile antenna I had sitting around. Any ideas that take in to account what I have stated above?