I chose to mount my CB antenna on my Canyon City spare tire carrier. It offers a nice location for the antenna mount to be located. After center punching the spot, a 1/2" drill bit was used to make a suitable hole and a standard 3/8"x24 mount was installed. Click here for details on installing the mount. Click here for details on install an RF coax connector.
Because I park my TJ in the garage, I have a problem with most
antennas clearing the roll-up garage door. I stopped by the local ham
radio store and purchased a Hustler 3/8"x24 Quick Disconnect (part # QD-2) for my
K-40 3' antenna.
The antenna QD comes in two pieces. One part screws into the antenna mount that I installed on the tire carrier. It has the same size threads as the antenna (3/8"x24) so no adapters are required to attach it. The remaining part is attached to the bottom of the antenna. It is drilled and tapped to accept the antenna threads also. I used a lock washer on both of them and tightened them securely with a pair of wrenches.
Once both of the QD sections are attached to the mount and the antenna, it can be connected. This type of QD uses a spring loaded quarter twist lock up which is easy to put on and take off. It holds the antenna securely in place while making it easy to remove in just a second. I have never had it come on the trail, regardless of how many branches it seems to get tangled in.
Once your antenna is mounted, run your coax via what ever path works for your setup. I used RG-8X coax. It is a lower loss replacement for the old and popular RG-58 coax. It is a 50 ohm coax so direct replacement is no problem. Make sure that when you route the coax, you avoid any situations that would leave the coax vulnerable to be snagged on an object while off-roading. Also be sure to route the cable so that it can not be cut, crimped, or smashed.
After you have the coax properly routed from your antenna to your radio location, it is time to adjust the SWR.
Here is an old but reliable SWR/Power meter that might very well be older than you. I got it in the early 70s from a CBer who worked with me when I was first in the Navy. It measure not only SWR but also power output and % of modulation. I might add that I have compared this unit to my more expensive power meters I have for my ham radio equipment, and it is quite accurate.
In order to accurately adjust your antenna, you will need to beg, borrow, or steal (OK, skip the steal part) one of these. You will be doing yourself a big UN-favor if you don't adjust your antenna for minimum SWR. Thinking it will be adjusted properly when you take it out of the shrink wrap is about as probable as you hitting the jackpot by playing just one quarter in the slot machine.
On the back or sides of the SWR meter, you will find two coax connectors. One of these will be labeled "Antenna". Connect the coax you just ran to this connector. Connect another coax cable, about 3' long, to the remaining connector. The other end of this cable will be connected to the coax connector on your radio.
Note that the following steps are generic in nature, but will be typical of those you will perform when you adjust your antenna for minimum SWR.
After you have the cables connected, apply power to the
radio. Set the radio to channel 20.
Put the SWR selector switch in the SWR Calibrate position.
Key the radio and adjust the SWR meter for a full scale reading. This is done by adjusting the Calibrate control until the meter reads full scale
Unkey the radio.
Put the SWR selector switch in the SWR position.
Key the radio again and read the SWR value from the meter. Note this on a piece of paper for future reference.
Adjust your antenna slightly, making it a bit longer and shorter (see the directions that came with your antenna). Check your SWR after each adjustment.
Your goal is to get the SWR as close as possible to a reading of 1:1 on channel 20.
When you have everything adjusted properly, the SWR measured on channels 1 and 40 will be somewhat higher, but should be less than 3:1. Most of the time, they will usually be around 2:1 or less.
If you favor one channel more than the others, you can also adjust your antenna for the lowest SWR reading on that channel. Here in Arizona, we use channel 4 all of the time for trail runs, so I have adjusted my antenna to favor the lower channels.
I thought I would include a picture of my HAM radios mounted on my windshield frame and the roll bar. Actually, they are just the control panels for the radios. The rest of both radios are mounted in the back of the TJ. This makes for a nice installation. Easy to use and never in the way. I wish they did the same for the CB radios. Unfortunately, it jacks up the price and I assume the CB manufacturers do not wish to do that.
4x4 Off-Road Homestead Firearms RC Flying