SWR just won't come down.....

Not sure what you mean about having the antenna grounded to the battery.

Normally the antenna is grounded to the metal frame of the vehical in order to provide the antenna with a large conductive metal surface to make the ground plane it needs. Since the antenna is mounted to your mirror bracket, make sure that the bracket mount has a good connection to the frame or body.


If that doesnt help, have your antenna and radio checked for damage - could be something like a damaged coax connector in the radio, or loose wires inside the antenna.

 

That is whats wrong...ground it to the chassis.

 

BTW... I think the TX light is suppose to be red when you transmit... Or am I wrong?

 

That would be correct...that the TX light goes red!

 

I would check your coax, it sounds like it is bad.

Also check the antenna mount, sometimes that nylon washer/spacer cracks.

Check the antenna for damage.

I would like to know how you have the antenna grounded to the battery?

Or did you mean the radio is grounded directly to the battery?

If the SWR does not change from CH1 to CH40, it points at your antenna system, that is why we ask you to check the basics stuff first

 

"The only thing I have not done is cut down the antenna and try that."

Your second mistake. The first is "The antenna is grounded to the batteries". Get rid of that. Especially if it is a long small diameter wire which would only serve to add inductance to the system right where it needs a zero reactance good ground. You are not telling us just exactly how or where you hooked this wire to the antenna. Since we cannot see it you must do better at providing information. After you remove the wire. Typically the stinger new is 2 or 3 inches too long but I would use the Wilson guide linked below. You are so far from resonance on the 40 that the narrow window of measuring from 1 to 40 tells you little. This is where an MFJ 259 proves itself to be so useful. As you likely do not have one use the guide and get close enough to use the CB to tune the antenna.

http://www.wilsonantenna.com/cutting.php

 

You did not say if your Kenworth was metal or Fiberglass, if its fiberglass you may need to switch to a N.G.P. Antenna System. (no ground plane) I own a fiberglass motorhome and swr readings where always high. I just recently purchased a Firestik NGP antenna system and swr dropped to 1.5 and I haven't even tried to tune it yet. cost was $38 and some change plus shipping . money well spent.
Hope this helps

 

Look at the mount. Make sure there is a plastic washer is on top of the mount and not the bottom of the mounting bracket. Next, is the bracket mounted to something metal that has a proper ground or body ground. What kind of coax are you using. one antenna means you are running single phase. Single phase requires the use of 50 ohm coax. Two antenna is cophased and requires the use of two 75 ohm coax linked together at the radio via a Y in the harness.

But it sounds like the antenna is completely grounded out. Only the bracket is supposed to be grounded not the antenna itself. The antenna itself should be completely isolated from ground.

 

It sounds to me that you may have a short somewhere in the antenna system. Either the antenna itself, the coax...or the mount.