2M/70Cm antenna SWR problem

[KC2NYU]

I have a Diamond X-200A dual band vertical antenna. I have had it mounted first on the roof and then in the attic, and now back on the roof. Regardless of the mounting location, I have used the same, RG8X cable run from the shack to antenna. (the run does have about 8 ft of excess coax) I have never before noticed an SWR problem with the antenna paired with my Yaesu FT-7800. Now I am seeing a 3:1 to 4:1 SWR. When I moved it back outside, I painted the white fiberglass antenna green for stealth purposes. I had read two articles on the internet regarding painting fiberglass antennas and both recommended using Krylon Fusion spray paint for plastics. Both authors said that they tested the SWR before and after the paint, and saw no change in SWR. But now for some reason, paint or otherwise I have an SWR issue. Can anyone give me some ideas of where to look for issues with SWR problems on a Dual band 2M/70cm antenna SWR issue.
Tnx and 73
Paul

[KL3HY]

I think the first thing I'd do is take the antenna apart and see if everything looks good on the inside.  If nothing's damaged there, then try a different piece of coax and see if the SWR changes.  If you still see high SWR, then see if you can borrow another antenna and try that on the original RG-8X coax. 

In a nutshell, I think you want to do some basic troubleshooting to narrow down where your problem is.

[K5WLR]

Had a Diamond X50 that was dropped from the top of a 30 foot tower When I tried to use it again, it had a 6:1 SWR. Not easy to disassemble; when I got it opened up, the tubing inside had split from the fall and the upper element had dropped down inside. I am still thinking about putting it back together after repairing it to see if it will still work.

[KC2NYU]

You guys agree that painting it with Krylon Fusion paint for plastic,  probably not the reason for the SWR change??
73
Paul