Question CB Radio issues, antenna interference

[Joe Hogan]

We installed a President McKinley CB with a FireStik antenna. While the antenna tuned up just fine SWR is 1.0, however, the interference caused by the antenna or antenna installation make the CB unusable.
No I have hooked up a new FireStik that was laying on the dash board, same problem. Installed Ferrites, no change.

I am going to try a President antenna rather than the FireStik this week but not confident as there is no ground plane.

Thoughts or good CB tech source in Central FL?

 

[AbdRahim]

Is the CB interfering with something in the coach, or vice eras? The location of the antenna cable can have a lotto do with this. On my initial install keying the radio would cause lights onthe das to light. I simply moved the cable and the problem disappeared.

 

[redbaron]

Antenna cables should never run parallel with other cables. Always cross at a 90 degree angle. Takes extra effort but resolves most interference

 

[Joe Hogan]

First trip with CB. Reception is in my opinion poor. Close in the radio receives good signal, but typically I hear only one side of conversations. Sometimes that is a good thing, but I’d like to improve range and reduce RF interference on the radio.
The radio shows a constant 5 out of ten bars of signal at rest. Static.
Squelched the radio is clear on close in radio signals. But with the squelch that high weaker signals are lost.
As mentioned above I thing reroute of the antenna coax is in order. The question is how to get that done.

 

[AbdRahim]

Is this an aftermarket installation? Sounds like you don’t know the routing of the coax.

The Firestik needs to be the ngp type (no ground plane), and must be vertical. Laying on the dash makes you horizontally polarized, while everyone else is vertically polarized, decreasing your signal.

The tip of the antenna also need to be above your roof for the best results.

You may want to visit a good CBshoo that specializes in big truck installs. Mine was done in Pa. Excellent work.

Also, keep in mind at the legal four watts, you won’t hear a legal radio more than 1-4 miles down the road.

 

[Joe Hogan]

Yes, it is aftermarket President McKinley. I know where the coax is, it runs down the A pillar. The excess coax wrapped under the dash ( problem). I’ll need someone to pull the a pillar cover to gain access. Thinking I’ll wrap the excess coax around a small piece of plastic pipe running down the A pillar to use up excess. Add a few ferrite to help suppress random RF.

 

[AbdRahim]

Big boy radio. Cool.

Likely no need to access A pillar. The excess is likely the problem. No coils of coax. It is better to do long loops and tuck the excess somewhere. How much excess coax do you have?

 

[Joe Hogan]

The coax is 15’ long and needs to be kept while per Firestik instructions

 

[AbdRahim]

Yes, but how much excess wire is there to tuck away between where it enters the coach and the back of the radio?

 

[Kevin D Pem]

Yup an air core coil.

 

[redbaron]

Q Is the length of the coax cable important?
A We find that it is very important ... especially with high performance top-loaded antennas. Your safest bet is to use 18 feet (5.5 meters) coaxial leads on all of your CB installations.

Q I only needed 9 feet of coax to go from my radio to my antenna. How should I handle the excess?
A What ever you do, do not roll it into a small convenient coil. It will become an RF choke. If you cannot let it lie loose under a seat or in a headliner, wrap it into a yarn-like skein of about 12 to 16 inches, put a wire tie in the center and tuck it under your dash, seat, etc.