Is it the antenna system or a CB radio problem?
Basic troubleshooting procedures require a process of elimination in order to get to the culprit. And remember easy & cheap 1st, hardest and expensive last.
Eliminate the headsets from the equation.
Can anyone understand your passenger? The likelihood of both headsets being defective is extremely low. If you are experiencing similar results from both headsets move on, it's not the headsets.
The antenna system is next.
With the antenna system you have coax, stud mount, antenna, and ground as possibilities. Check them out in this order - ground, antenna, stud mount and coax.
Checking for a bad ground
If you move the coax or grab the antenna bracket and the SWR fluctuates you have a ground problem. The SWR should be below a 2.0 and not fluctuate more than .1 up or down when moving the coax or grabbing the bracket.
In other words 1.9-2.1 of fluctuation is ok. Remember, paint and primer are your enemy.
Pinched or melted coax jacket is not good- replace it.
Spin the antenna in a circular direction and check the SWR. Look for serious fluctuation or a spike.
If it exhibits either replace it and same for the stud mount is screws into.
If SWR testing indicates the antenna is electrically short (higher SWR on ch 1), you may have a ground problem. Touch the antenna bracket while keyed and watch for SWR fluctuation. Do not touch or even get close to the antenna.
Move the coax around bending it, again watching for SWR fluctuation. If the SWR fluctuates a ground problem exists and must be corrected before proceeding.
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Tuning your antenna
Wire-wound antennas (without mechanical tuners)
Check your antenna SWR on CH1 & CH40. If the SWR is higher on ch 40 as compared to ch1 remove wire from the top of the antenna.
Remove the antenna cap, remove one wrap of wire and cut it off. Put the cap back on and recheck the SWR again on ch 40 & ch 1.
As long as the SWR is higher on channel 40 continue to cut. Do not cut more than one wrap at a time.
If the SWR is higher on CH1 and a ground problem has been eliminated bend the end of the wire (that wraps the antenna) straight up the fiberglass shaft and lap it over the very top of the fiberglass shaft. Put the cap back on the antenna. Check the SWR on ch 40 & ch 1. The goal is to reverse the situation so that ch 40 has a higher SWR than ch 1.
If ch 40 is now higher cut 1/8 inch of wire, put the cap back on and check the SWR on ch 40 & ch 1. Continue with this process until ch 40 & ch 1 are relatively the same.
If the SWR does not reverse replace the antenna. DO NOT replace it with the same brand and length. The antenna may be reacting badly so replacing it with the same thing will have similar results. Consider a Firestik FL or FS series antenna and the longer the better.
Tips & Tricks
Considerations- the correct length of coax is 18 feet. Motorcycle manufactures do not follow this rule.
Use a coax cable that is 18 feet long, has 95% shielding, and poly vinyl insulation. Your exhaust is HOT! Poly foam coax will melt.
Consider the MU8R18 coax from Firestik. It meets all of our recommendations and offers a big plus. The screw on end (PL259) detaches and makes running the coax cable through tight places a breeze. The coax cable is designed to be used with a K4R (Fire Ring) stud mount from Firestik.
Remember this, paint and primer are your enemy. The antenna system will not ground through it and adding wires is NOT going to work.
Braided straps with a basket weave design and are flat and wide are acceptable providing the strap is short. 2 feet at a maximum length and the wider the strap the better. |
