Where is your Winegard mounted? When I mounted mine, I did some research and found most recommended it be mounted behind the first AC. I contacted Bill Adams, sat dude, and he said Alpines can't mount in front because of air flow. No one has a good reason other than it's an aero thing with Alpines. So I mounted mine behind the first AC, and I don't have any problems with rattles or noise. I have a 2004 40 also. I took the King Dome off and it had a junction box located behind the KD. I ran two coax and control cable from there inside electrical flex cable and secured to roof from that location to new sat dish with clamps to roof.
I found one link on subject from Bill Adams and Wayne R. here it is.
Originally Posted by Wayne R
If was me I would also mount the Kingdome behind the front AC unit. Alpines are notorious for noisy sat dishes mounted up front. I removed the Kingdome from mine for that reason and installed a replacement dish behind the front AC. Do a search and you will find where MotoSat actually relocated the executive dishes on early Alpines. Due to the fact that they were getting destroyed up front. Louis Birch actually taped a video camera on the roof to record the violence the dish was experiencing going down the road.
While the Alpine Coach does have a known issue with open face dishes mounted ahead of the front A/C, there is nothing about a dome that should cause an issue if it is mounted forward. I would look for a mounting location that allows the shortest cable run. Yours is the first I have heard about a dome causing noise. Was it just wind noise or some kind of banging? The noise from the open dishes is caused by some kind of wind "eddie" created by the front cap that gets under the open face of the dish and can lift the dish causing it to flop up and down creating a banging noise and ultimately destroying the antenna.
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