Firestik antenna SWR in the 3 +

I have a Western Star. The factory antenna is basically The Identical length of the new firestick I just bought. The factory antenna SWR is that a 1 maybe 1.2 with nothing being changed except the antenna, the fire stick is in the 3+. I tried several different length mounting studs to give and take away length from the bottom of the antenna ( I thought I was buying the tunable tip, I got into a hurry and purchase the wrong one) I used the tunable tip on a Mac with much success, an SWR of 1. With the fire stick on the Western Star, Channel 1 is that a 3 and channel 40 is at a 3+ Any ideas?

 

Never mind on that. I brought the antenna back. I didn't want to have to trim it. I know that's kind of lazy but it's so much easier to trim a steel Whip or adjust a top load antenna.

 

I came to the logical conclusion that I should have had in the beginning which you is, if it ain't broke don't fix it. I started thinking to myself... Why would I change the antenna when I basically have a perfect SWR on a properly calibrated radio?

 

I just realized I didn't even answer your question. I just left the factory antenna on it.

 

I had a k40 trucker on it with a 1 ratio (almost identical length as well) but I thought it had a defect because my receive was awful. I tossed it and mounted the original and had the same issue. Come to find it was the mounting assembly. So I assumed the firestick would be the same length or close with the same ratio. I don't think that is the case. Different antennas and manufacturers have different impedance so I'm pretty sure the length can vary (possibly several inches)