102" whip on 2020+ freightliner cascadia

3:1 looks like something in the cable, check make sure the mount is not shorted to ground, make sure your connectors are properly soldered, also make sure the ground for the mount is a good solid ground. If you have too much of it running to close to metal pieces (such as body parts) it can raise your SWR/.

 

YouTube is your friend.

JD

 

The ohm readings depends on the ohm meter. If it's a digital meter, touch the 2 probes together and see what the reading is. Sometimes the meter will show zero, other meters may show around 3 or 5. This gives you a base number to go by. Then check the ground straps to the antenna mount. You should get basically the same reading as touching the probes together. If the reading is a lot higher than the base reading, then you need to address that issue.

 

Yes, or very close to it. If the ohm reading is high, then there's not a good ground connection to the metal. That could be due to paint or corrosion, etc