Wilson trucker 2000

It sounds like your setup is resonant at 10 meters. This usually would indicate the antenna is a bit too long for 11 meters for the location it is being tested at. If that's not the case, then there is something else causing the aberration. If shortening the length doesn't help, then it may be the ground, the "second half of the antenna" otherwise known as the truck, the coax, or internally the coil, some soldered connection somewhere? I'm not skilled at chasing down such problems with an antenna analyzer. I have tuned all of my antennas with a simple SWR meter and antenna length manipulation, so I actually don't know if mine are perfectly resonant or not, but they do perform well; for me, anyway.

 

Actually 28 - 29MHZ is the 10 meter band.

 

That's good advice for the OP. Of course having low swr reading, doesn't mean the antenna is resonant. If the antenna's impedance is 25 ohms on a resonant frequency, then the swr would be 2:1. 50/25=2. If you adjust the antenna to a frequency lower than the true resonant point, the indicated swr will decrease.
Mobile antennas can sure be a mystery sometimes. There's a lot of different factors involved when it comes to matching a mobile antenna to the radio.

 

Whats the ant on,what and how are you grounding?
Got this god awful feeling your running a gnd wire from mount to chassie vs the aspect of bonding....
What changes have you made sence you tossed the ole factory ant and went with the next one..
Same ant stud,same coax,corrision?

 

How does the hinge connect to door then..Been humpteen yrs sence i saw a piano hinge..

 

Maybe its not the wilson...Maybe the old factory was so crappy it was hideing an issue that the wilson was pickin up..

 

Gotta be bolts somewher betweeb door and cab..Just because of that hinge alone would cause an issue. .Dirt,rust,plastic bushings,anti sieze,thread lock dont help any either..