External swr meter has me confused

Your biggest mistake is trusting the cobra 29 swr readings to adjust your new antenna. I had a fellow company driver complain about his new cobra 29LX not receiving or getting out very good. The Wilson antennas on his truck were rusty at the mounts and coax connectors. My antenna analyser showed a very high swr reading of 5 - 6 for swr. No surprise there. The cobra 29 swr meter showed a reading of 1.2. That seems to be the magic number for swr readings with these radios, no matter what the real swr is. The swr vr6 pot inside the cobra 29's are always out of adjustment from the factory.

I would trust the cheap truck stop external swr meter any day before the cobra internal swr meter. I'm confused by what you mean by loud and clear 1.2 swr reading on your radio. You claim your getting out and receiving good, but that doesn't explain the high swr reading with the external meters. Did you install the coax connectors on the coax yourself? There's a problem in your antenna system somewhere. Never trim and tune an antenna by the radios swr meter. At least not the cobra 29s.

 

What was it acting like?

 

Well I would put the original antenna and mount back on with the new coax and see what happens.

 

Try all your old gear then keep adding the new to see where the change occurs..
Possible that its the piece of coax your useing with the cheap swr meter...
Did you chk your grounds(bond points) with a multi meter,are you doin the old ground from bracket to chassie bs cause thats wayy wrong if ya are..
As cars n truck get older rust and corrossion build to so keep that in mind..

Replace all your bond straps(assumeing your not useing awg as gnd wire)
Your gnd is not goin from ant bracket to chassie or battery right?

 

It was a very busy weekend for me, so I haven't had time to check back. My main advise to your original post was to ignore the cobras built in swr meter and I gave you a reason why. You bought a new antenna, but you didn't say what brand and how long it is. Anything under 4ft long doesn't work the best for 11 meters. You bought new rg8x coax made by astatic. I've never used that brand of coax, hopefully the astatic coax is better than their new mics. What percentage of shielding does this coax offer? You want at least 95-97% shielding. According to the external swr meters (including your friends) you have an antenna system problem. Sounds like you resolved that by trimming down the antenna to get a good swr reading on the external swr meter. You say its weird that you had to cut off 3 inches to get a good swr reading compared to the original antenna. All antennas are going to be different. I like running the hustler 4ft antenna. Its a 10/11 meter antenna. I have to cut more off to use it on the 10 meter band than the 11 meter band. To me the real question is how much reflected power do you see. That's really more important than swr readings. But if your external meter doesn't have power reading capabilities, than you have to go by the swr readings. I would check the bonding like Craig suggested.