Section 7: Mounting the Antenna
I already covered the locations and such in Section 3
, so I’m not going to repeat. But I will cover some mount plates.
Typically, a 3’ whip antenna won’t need super heavy duty mount hardware. But if it’s a stiff fiberglass one that is always whacking limbs, it might. Just try to use your best judgment on antenna length, thickness, flexibility and location to determine how heavy duty your mount hardware should be.
There are also some neat accessories that will help with antenna management. There is a fold down piece that allows you to fold down the antenna in a direction when you aren’t using it, or going under something big. There are also detachment pieces that let you remove it altogether.
You may want to tune it before tightening up the antenna and routing the coax through the truck. You never know if you are going to have to move it or not. With it mounted on the tailgate, roof, or hood, it shouldn't be a problem. Better safe than sorry.
Since I don’t mount on the roof or hood, and I am using a 4’ very flexible whip. I will not be using any attachments, but it’s your preference. Remember sometimes attachments can affect your tuning (covered next
Because it’s sturdier than some of the other tailgate mounts I have looked at, I used this one:
This does not come with the antenna mounting bolt, so you will need to buy that also.
When mounting this one, be very careful
with the factory bolts. They will strip out rather easy.
There are a few types of coax you can use, but they all should use the PL-259 connector. Buy a high quality cable since these are not regulated and sometimes are manufactured poorly. On the lower end, you can go with RG58, but may get some feedback issues. On the high end, there is RG-59, but it that may not be necessary unless your running dual antennas or have terrible feedback issues. The one I recommend is RG8X, it's the middle ground. for a mobile CB setup in our trucks, RG8X is fine. We aren't wiring up a radio tower.
This is a good calculator for coax (in case you want to compare coax at frequency 27 and 18' length...):
Grounding can vary by antenna. Some use the mount as the ground, and others come with a ground wire. If your mount is not well grounded, you will have to run a ground wire from it. Take into account the length of the ground wire as well. Try to keep it as short as possible and under 2' in length. Over 2' might not be a problem, but you will have to take it into account when tuning the antenna for low SWR (covered next
). I tested 3' to 7' and started seeing issues after 5'.
I ran the ground and the antenna coax into the tail light and down through a hole. I grounded the antenna to the frame. Then I ran the coax up over the wheel well, back down and along the frame, and finally up through a grommet just under the driver’s seat.
If you end up with a lot of extra cable, don't store it in a coil/circular shape. This can cause issues. Instead use a figure 8, or wrap it like an extension cord and tie it in the middle. There is a scenario where coiling the cable is a good thing, but only if done right and in the appropriate diameter. This is for the amateur radio guys, for our simple application of CB, not coiling the cable is the thing to remember.
I had to use automotive sealant around the hole I made in the grommet to prevent leaking. If you do, make sure it's a very flexible sealant.