CB Tuning issue High SWR

[Speedy_RCW]

You mentioned checking continuity but have you checked for shorts between the shield and electrode in the coax? You could get good continuity readings and still have an issue. Make sure you also check where you SHOULDN'T have continuity if that makes sense. As far as grounding the gate, I'm running the same CB and antenna mounted to my gate with no issues.

 

[Moonraker]

You mentioned checking continuity but have you checked for shorts between the shield and electrode in the coax? You could get good continuity readings and still have an issue. Make sure you also check where you SHOULDN'T have continuity if that makes sense. As far as grounding the gate, I'm running the same CB and antenna mounted to my gate with no issues.

Are you running the nylon washer?

 

[JeepJeep75]

I just did my CB install last week. I went ahead and just ran an external ground wire from the antenna mount back into the inside of the cabin to the base of the C-pillar of the factory roll-cage above the tail light. After checking with an ohm meter, there is 0.0 ohms between the antenna mount and negative battery terminal. The antenna "hot" should not be connected to ground at all. With the ohm meter it does and should read "OL" which means open (no connection). Here's a pic. Hope this helps...
You can see the nylon isolator on the top of the mount, between the antenna "hot" side and the mount. My Uniden says I have a SWR of 1.0 to 1 on channel 1 and 1.1 to 1 on channel 40. Not to sure I trust that reading but it seems to work well. I'm using a 3 foot Firestik with a quick-disconnect.

 

[jeeeep]

if you're doing a continuity test, do it for the ground on the mounting bracket to the ground bolt inside the Jeep. if you have a weak ground that will contribute to your high SWR.

you can always run a 2nd ground wire from the bracket to the ground bolt in the back of the Jeep.

Is this how you have yours?


I prefer to just ground the coax, I've seen too many people have issues with the fire ring connector

 

[Speedy_RCW]

Are you running the nylon washer?

Yes I am. I'm running the fire ring and have it configured just like Jeeeep has posted. Is that how you have your coax set up?

 

[jeeeep]

Yes I am. I'm running the fire ring and have it configured just like Jeeeep has posted. Is that how you have your coax set up?

did you remove the paint or powder coating from the bracket where the bolts mount to the tailgate? that's your ground from the bracket to the Jeep

 

[Moonraker]

Thanks guys ,helps me a lot ,hope it helps the other cat. I think I will ground my bracket.

 

[Highpocketse5]

Also I have to ask, what are you using to check the standing wave? If your using a function of the CB itself, those meters are not reliable or intended to be very accurate. In fact according to cobra the built in swr meters on their transceivers have a ratio deviance of +/- 1.086

I have a stand alone SWR Meter. I switched power directly to the battery with no luck. Reading are still well above 3. I did check the coax with an Ohm meter. Everything tested good. Puzzled???

 

[Highpocketse5]

After reading through everyone's posts I think I am going to have to ground my bracket as well. Isn't there a ground under the storage location in the rear of the jeep?

 

[tinman760]

Yup, grinding off the powder coat worked for me. SWR was off the chart, now it is flat with a 3' FS. Star washers may help, also. $.02

 

[Havoc40]

Well, if you flipped the nylon washer to the bottom side of the mount, that's part of your problem. It should go on top, like the picture shows. If you look at the picture, the top metal ring on the coax should have continuity to ground. I ground off powder coat where the metal ring would sit, as well as the back side of the mount. Then ran a separate ground from the mount to the inside and grounded it to the tub where the tie down bolt goes through.

As luck would have it, I didn't have to touch the antenna tip! I had perfect 1.2-1.3 SWR right out of the gate

EDIT: Verify a good ground on the tie-down with an ohm meter. If I remember right, the closest point didn't have a good ground (I was reading like 40ohms). I had to use the hole that's closest to the back seat, which had 0-1ohm resistance.

 

[Highpocketse5]

I installed a ground and triple checked everything this morning. Just went out and set SWR. I had 1.2 on channel 1 and 1.5 on channel 40. Thanks everyone for the help. I did run the ground under the tie down point. Like was mentioned in an earlier post.

 

[Highpocketse5]

Here is a pic of my mount. For any others that have issues. Take note in the placement of the nylon washer. It's a key point.

 

[Desert Crawler]

OK. Now that the OP has his set up figured out, I have a quick question for you CB gurus that I have been wondering about. If you use a separate SWR meter with a short jumper coax. Tune your antennae. Wouldn't removing the SWR meter and short jumper cable change the tune. I have a meter, but don't want to leave it installed after the tune. Would that be a problem?

 

[Highpocketse5]

OK. Now that the OP has his set up figured out, I have a quick question for you CB gurus that I have been wondering about. If you use a separate SWR meter with a short jumper coax. Tune your antennae. Wouldn't removing the SWR meter and short jumper cable change the tune. I have a meter, but don't want to leave it installed after the tune. Would that be a problem?

That's a good question???? I'd like to know as well.

 

[Moonraker]

I think the ground is going to be my issue as well....can't wait to try it. Thanks y'all [emoji322]

 

[Uncle Jimmy]

Fairly easy fix.... 1. Use a 4ft antenna instead of the 3 ft.... Then try and set SWR.... I do believe this will solve your issue.

 

[Uncle Jimmy]

Desert Crawler,
Yes you can remove the SWR meter and it will not change the tuning.... No need for it after you tuned the antenna.

 

[deepwater]

OK. Now that the OP has his set up figured out, I have a quick question for you CB gurus that I have been wondering about. If you use a separate SWR meter with a short jumper coax. Tune your antennae. Wouldn't removing the SWR meter and short jumper cable change the tune. I have a meter, but don't want to leave it installed after the tune. Would that be a problem?

No the SWR meter will not affect the tune.