CB Tuning

[JzzR83]

I have installed a CB into the jeep and would like some advice as to where I should start the troubleshooting. My SWR meter is saying 2:1 on channel 1 and 40. I would like to get it a little lower if I can. My setup is as follows:

-President Electronics USA Bill CB Radio
-Wilson 305-830 18' Belden Coax Cable with PL-259/FME Connectors
-FIRESTIK K-4A CB RADIO ANTENNA HEAVY DUTY SO-239 STUD MOUNT
-Rugged Ridge 11503.89 CB Antenna Mount
-Firestik SS-3H Heavy Duty Stainless Steel Antenna Spring
-FireStik K-1A Push-n-Twist quick disconnect
FireStik FS-4BK 4 (r) Ii Fs Series Tunable Tip Cb Antenna
-Astatic PDC1 100 Watt SWR Meter

For the Rugged Ridge mount I did grind off the coating to bare metal for the antenna and the mounting bolts. All of these items are pretty standard so I assumed they would work well together and it would tune easily. The only thing I can think of is I do do not have a jumper coax cable so I am using another full length (18 ft) coming out of the CB into the SWR meter, and the other installed 18 ft that is for the antenna. Would that make a difference?

Before I rip everything apart I just wanted to ask for some advice and tips as to where I can look first. Here are to pics of the mount, stud, QD and spring.



(I did drive south a little ways to an open farm field so there were no trees, houses or any obstructions when I tested.)

 

[old_man]

It isn't really ideal having the antenna that close to the metal rim. Have you tried adjusting the tip and watching the SWR?

 

[Prerunner1982]

What's the measurement on channel 20?
You could try taking 108" of wire, strip one end and connect it to the metal part of the pl259 connector at the antenna mount. Lay it out as straight as possible and recheck your SWR. If it's better you need a better ground.
The tailgate is really one of the worst places to mount a CB antenna as it lacks a sufficient ground plane and can put the antenna too close to the wheel and tire (steel belts).
SWR is a curve, higher at the ends so if it's the same on channel 1 and 40 that may be about the best you can do.

 

[Roam_CO85]

Most of those fire sticks are trim to tune. Some are adjustable. But thats the hardest part of them is you get very lucky if you can throw one on and go. The cb that i have had it professionally tuned by the cb guy here in loveland ( he disappeared again though). Could reach 10 miles turned up. Always told me to stay away from doing the fire sticks because of tuning them. If you can play with it an your meter. Hauling cattle sense 2011 have spent alot of cb time. Wilson is a good antenna or Francis whips. The whips dont break as much. Fire sticks are pretty hardy

 

[SubeeBen]

Ditch the spring & quick disconnect. Had the identical set up & could not get better than a 2.5 on the swr meter. Removed spring & disconect & tuned it to 1.2 . Just because the sell these items does not mean they work. At least on my 2017 Jeep Jku. Just my 2 cents, good luck

 

[Roam_CO85]

Those springs are junk. They rust really bad too and make things look gross. Had one on my semi that would wack back an fourth on thd cab. Even a excessive cord will throw off readings. Ive seen some guys mounting them to a front bumper good idea but a lot of steel if its steel.. bad ground of poor location or to much hardware.

 

[sabjku]

I have that same mount, installed on the tailgate as well. Did you make sure you grinded off all of the powder coating on that mount, right where the flat washer makes contact? If you did, double check it again, and make sure the washer is contacting bare metal, with no powder coating. I got my tuning down to the low 1-1.2'ish after that.

 

[JzzR83]

It isn't really ideal having the antenna that close to the metal rim. Have you tried adjusting the tip and watching the SWR?

I would agree it is not the best placement, but I figured it must not be sucky seeing that it seems like 75% of Wranglers around my area have the antenna mounted there.

 

[JzzR83]

Ditch the spring & quick disconnect. Had the identical set up & could not get better than a 2.5 on the swr meter. Removed spring & disconect & tuned it to 1.2 . Just because the sell these items does not mean they work. At least on my 2017 Jeep Jku. Just my 2 cents, good luck

Funny you said this...after work yesterday I asked my ten year old daughter if she wanted to help me troubleshoot. We discussed the setup and I explained to her that we need to eliminate some items and try to tune the antenna to see where we stand.

First I removed both the spring and the QD. We were able to tune it to 1.5 or 1.6ish. Fully acceptable in my book.

Second, I added the QD with no spring. Rubbish, 2.5 again.

Third, no QD and only the spring. 2.0. Still Rubbish.

Fourth, tune it again with just the antenna as that was the best setup. 3! WTF mate! I just had a 1.6ish twenty minutes ago. And I noticed the local weather band that was crystal clear did not come in at all.

Simple projects like tuning an antenna always seem to go off the tracks somehow. My only guess at this point is the coax cable has failed already due to opening and closing the tailgate 15 times. (I read in some amazon reviews one guy who had this happen). After a couple hour of this happening I had time to think, research and drink some beer. Jumped in the jeep, turned on the CB for the heck of it and then the weather channel was crystal clear again. Seeing that it will rain all day today I am gong to test the continuity of the cable while opening/closing the tailgate a bunch of times to see if that is the issue.

 

[Roam_CO85]

Ive come across power supply issues in the past where hard wiring it to the battery always made it kinda wonky. But id always tie it into the twelve volt power supply in the cab and it worked better. The cables are so touchy. If they get pinched in anyway kinked makes them go down hill fast! I learned how to trim them and make my own connection that helped take a lot of slack between the receiver and the antenna but finding a way to it doesn’t get slammed in a door or a tail gate helps alot

 

[JzzR83]

Ive come across power supply issues in the past where hard wiring it to the battery always made it kinda wonky. But id always tie it into the twelve volt power supply in the cab and it worked better. The cables are so touchy. If they get pinched in anyway kinked makes them go down hill fast! I learned how to trim them and make my own connection that helped take a lot of slack between the receiver and the antenna but finding a way to it doesn’t get slammed in a door or a tail gate helps alot

The CB is currently wired to the Apollointech switch pod which is very nice. Depending on what I find with the continuity test that I will do this afternoon I may pull some of the extra line that is under the passenger seat to the tailgate and make a loop instead of going through the factory loom with the power wires as it gets bent at a pretty severe angle every time the tailgate is closed.

 

[SubeeBen]

Funny you said this...after work yesterday I asked my ten year old daughter if she wanted to help me troubleshoot. We discussed the setup and I explained to her that we need to eliminate some items and try to tune the antenna to see where we stand.

First I removed both the spring and the QD. We were able to tune it to 1.5 or 1.6ish. Fully acceptable in my book.

Second, I added the QD with no spring. Rubbish, 2.5 again.

Third, no QD and only the spring. 2.0. Still Rubbish.

Fourth, tune it again with just the antenna as that was the best setup. 3! WTF mate! I just had a 1.6ish twenty minutes ago. And I noticed the local weather band that was crystal clear did not come in at all.

Simple projects like tuning an antenna always seem to go off the tracks somehow. My only guess at this point is the coax cable has failed already due to opening and closing the tailgate 15 times. (I read in some amazon reviews one guy who had this happen). After a couple hour of this happening I had time to think, research and drink some beer. Jumped in the jeep, turned on the CB for the heck of it and then the weather channel was crystal clear again. Seeing that it will rain all day today I am gong to test the continuity of the cable while opening/closing the tailgate a bunch of times to see if that is the issue.

Doh !!!!! Might have to re-check my coax. I have it wired through the tailgate as well & never thought about opening & closing/flexing the coax cable every time you open & close. Looks like I’ll be working on the Jeep this weekend .

 

[Roam_CO85]

Nothing against the magnet roof top antenna guys but yeah closing that coax cable into a door frame isnt the greatest idea. Plus scratches the heck out of your roof. They make metal braided coaxs that work pretty good. Have a good end that can be threaded through stuff and it threads into a connection point.. pretty tough set up. What do you all run for a radio? Galaxy guy here. Spent over 400 for it itll do more things than i ever want todo with it. Been wanting to get into ham but havent pulled that trigger yet!

 

[old_man]

In the past I have run a bulkhead RF connector through the roof and mounted an antenna to it. You can get nice ones ready made to mount an antenna on the outside, with a low profile right angle inside, with a cable for the radio already attached. Your signal will always be better if your antenna has a good symmetrical ground plane, such as the metal roof of a vehicle. At best a gutter, bumper, or carrier mount will severely change the radiation pattern. For instance if you mount it on the rear, the strongest signal will be over the metal (top) and will be to/from the front. If you mount in the middle of the roof, you will pretty much have 360 degree coverage and a lot stronger signal. Many times it can be double.

If anybody is interested, I can post up some links.

 

[Roam_CO85]

In the past I have run a bulkhead RF connector through the roof and mounted an antenna to it. You can get nice ones ready made to mount an antenna on the outside, with a low profile right angle inside, with a cable for the radio already attached. Your signal will always be better if your antenna has a good symmetrical ground plane, such as the metal roof of a vehicle. At best a gutter, bumper, or carrier mount will severely change the radiation pattern. For instance if you mount it on the rear, the strongest signal will be over the metal (top) and will be to/from the front. If you mount in the middle of the roof, you will pretty much have 360 degree coverage and a lot stronger signal. Many times it can be double.

If anybody is interested, I can post up some links.

Id like to see the links if its not much trouble! I agree if your able to Mount that sucker somewhere high. The tail gate of a jeep is a good place but your limitations are high because cb radio is pretty much line of sight for most vehicle mounted units. Back when it was big and the radios were pushing 40 amps you could reach a long ways. Now that the ten codes are history you cant get much out of them

The higher the antenna the longer the reach. The more metal objects around that unit or cord. Its for sure a line of sight deal

 

[Roam_CO85]

My dad was a truck driver for 34 years. Use to think it was soo cool to put one in every vehicle i owned. I still do but even trucking with one. No one uses them anymore so when you hear chatter on it. It scares you. Hauling cattle when you ran four five trucks deep it was fun. Running with two guys you got tired of the guy before youd get 100 miles down the road. I never really trail with other people but still run it. For people you meet on the trail

 

[old_man]

Id like to see the links if its not much trouble! I agree if your able to Mount that sucker somewhere high. The tail gate of a jeep is a good place but your limitations are high because cb radio is pretty much line of sight for most vehicle mounted units. Back when it was big and the radios were pushing 40 amps you could reach a long ways. Now that the ten codes are history you cant get much out of them

The higher the antenna the longer the reach. The more metal objects around that unit or cord. Its for sure a line of sight deal

UHF VHF PL259 to SO239 bulkhead 90°for car radio Mobile Antenna mount RG58 10FT | eBay

SO239 bulkhead 90° to PL-259 male connector Antenna mountRG58 10' MADE IN USA.

www.ebay.com

There are variations that have a larger collar and support a larger base antenna with a quick disconnect NMO.

NMO MOUNT 3/8" HOLE WITH 15.5ft RG58A/U / L-195 CABLE WITH SMA CONNECTOR | eBay

MADE IN USA.

www.ebay.com

There are variations of this with different connectors for the radio.
With both of these, you can select a variety of antennas.

 

[Roam_CO85]

Oh i gotcha! I know what you are talking about now. I had a fire stick cable on my 08 ram that was a hood mount and didn’t have enough room to get a normal connector underneath it. I like this a-lot more the other one was kinda cheap i felt