swr issues

If you go with just one antenna, be sure to change the coax! The coax harness in the truck now is most likely 75 ohm co-phase wiring harness, which won't work with just one antenna...

If you get it set, but SWR jumps around all over the place while your driving, that's partially normal, since your moving and your surroundings is constantly changing...But if it jumps dramatically, like from 1.1 to 3.0, then you don't have a good ground somewhere, like maybe the antenna mount, or a bad coax connector, or possibly the mirror bracket is not making a good solid ground to the door, or could even be the door itself does not have a decent ground when closed...

 

It's most likely them if others come in clear.

 

Soooo..... Ya. My problem is similar but not. I have a 2015 Kenny T680 with dual mirror antennas. My issue is fun, to say the least. Swr is somewhere around 8 on channel 40 and 4 on channel 1, with antennas installed as prescribed by KW. If I hold the antenna in my hand (meaning not mounted), I get SWR somewhere around 2 ish and level across all channels (meaning if I could hold my antenna driving down the road I would get better readings and might could find tune them to be better).

Went to a cb shop and the crackpot (I don't mean he wasn't wise, just that Meth and him were peas and carrots, or he took one too many volts) told me the issue was the coax on the drivers side and that KW would likely warranty the work. That's not good enough for me because it'll take months to be able to get enough downtime for them to do the work without putting me out of miles I can run.

My concern is this, if grounding is an issue (and it very well could be), why would it improve if I'm holding the antenna sitting in the drivers seat?

My setup has been changed with similar results so you can suggest for Cobra 29LTD Classic, stock Kenny whips, or Bearcat 880 with oil cooled cool made by truckerspec (bought them to see if adjusting it would be easier, however I'm worried cutting the whip as much as it seems to need it would make the antenna about an inch long. Any help would be appreciated.

 

If your swr is that high, you definitely have grounding problems. The reason your swr drops when you touch your antenna, is because you are providing an rf ground by touching it. I'm not a fan of factory setups. Multiband antennas providing signal for more than just your cb is no good imo. If it were me, I would run my own antenna, longest one you can use, and mini8 coax. Don't use the factory coax. Hopefully that will take care of the problem.

 

What Bout Z said above and I will add: It is not really a ground issue pre se. You need to do some bonding. Running one long ground wire to the frame, though done all the time, is NOT the fix you are looking for. Using braided flat strap is the best. Coax works well. Or use that real fine wire in a large gauge like a 10 ga. that the stereo shops use. Make short runs. Antenna mount to door. Door to body, body to frame. Keep your runs as short as possible. Use good quality coax and as long of an antenna as you can get buy with.

 

The new Pete Im driving has the antenna mounts on the cab not the door. Seems to work well, installed my Galaxy and even turned up I still have a 1 to 1 flat on CB

 

Powder joints are the antenna mounts on your Pete forward of your door instead of behind the door on side of sleeper? Saw a few done forward thought at first it might be a driver mod instead of factory. Never mind just saw you had changed the picture on your post, that answers the question.

 

Our fleet is about 250 trucks. I slip seat and have driven a large number of them. I've seen perfect SWR, and yet it still won't xmit/rec over a mile many times. I know two drivers that claim their factory set up works decent. On the Freightliners, and I assume others as well, there is a antenna trimmer inside the dash that is supposed help if it is adjusted correctly. Now even these two I speak of don't have great range, but it is better than everybody else truck.

 

Figured out my issue, and it was a costly one lol. The original setup was perfect save for one flaw: the coax through the mirror connects to a barrel of sorts, switching it from the dual phase coax to a mini connector, then back to a full size at the antenna on the mirror, connected to a stud and then the antenna itself. The mini connector out of the cab was not connected on the driver's side to the barrel, causing swr to be around 8.0 on 40 and 6.0 on one. Before I caught that it wasn't connected, I had swapped antennas to some truckspec oil cooled thingymajiggers cause they looked nice (I dunno, becoming a sucker for chrome I guess). Anyway, after connecting that coax, it brought it down to previous posted signals, still no Bueno. Tried bonding and all that, no dice no change. Last ditch effort I put the factory KW antennas back on, and BAM, channel 1 is around 1.16 and channel 40 is 1.45. Feeling slightly dumb, but hey. Learned a valuable lesson. A meth addict makes a terrible CB tuner, and I'm not far behind that. 😂😂

Everything I read about making sure you had the right antenna for the setup (ie ground, etc) and it never dawned on me until this morning. Haven't tested range yet, but I will eventually. In the meantime, I will find a good TWEAK AND PEAK guy somewhere and see if anything else can be done, staying legal but at max wattage. Anyway, thanks for the help. I will go back to reading stuff until my next mistake, er, I mean issue.