My CB has no range

Some call it a modulation box but most refer to it as a Junction box. The stock installations on most Class 8 trucks use the antennas in the system for anything AM/FM which includes Citizen Ban (CB) radio. Music radio stations and CB radios run on the same type of radio waves but at different frequencies and frequency levels/bands.

The stock antenna(s) are wired to the junction box first. Then they split (per say) in the junction box for their application purpose - the box, in simple terms, changes whatever type of coax comes from the antennas to the box to the coax type needed for the application it's intended to be used for: the CB coax cable is ran from the box to where it connects to the CB radio after it's converted from the antenna coax inside the box, and the AM/FM cable is routed from the box to the stereo head unit that plays music after it's converted from the antenna coax type in the box. This is why some have had issues with the stock CB antenna reception or transmission quality.

Without getting into tech nerd details the issues are pretty much because there's too much stuff in the wiring; the AM/FM head unit wires, the CB coax cable, the junction box, and the stuff inside the junction box that separates them instead of a straight wire from antenna to radio. It's also why to avoid interference or issues with reception or transmission it's best to install a separate system dedicated for the purpose you want it for such as if you want to use SiriusXM run the satellite antenna wiring separate and straight to the head unit, run your own antennas and coax for CB straight from the CB antenna(s) to the CB, and use the stock antennas for AM/FM (music) radio stations only.

I agree with this. Like others said it's most likely a ground but it could be what I mentioned about the junction box. I won't claim or pretend to be a CB expert but I am very well versed in how radio wave frequencies work from previous experiences programming 2 way radios and emergency personnel communications. I had to learn and fully understand radio wave frequencies and what's allowed for use by the FCC (a ton of stuff about radio waves and frequencies). I have also been a Class 8 mechanic since the 90s. I don't know everything perfectly but I hope what I've shared helps.

If the wiring is straight from the antenna(s) to the CB and the grounds aren't corroded or damaged the quality of both the antenna(s) and cable it self make a difference. If you want good, long range, reception and transmission for a CB radio invest the funds in a good 3000+watt single antenna and RG8X coax cable for it. If you want to run dual antennas, again, invest in good long range antennas but use RG-59 coax cables.

 

Nicely done, Arel3.

A reminder that I’ve found good info — in general — about mobile installations first at:

www.K0BG.com

and at

www.eLightbars.com

For 11-meter and Amateur

www.wwdx.com

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Yeah nicely done but some things are wrong.

 

When did he post that? Last I checked, I easily heard him about 15 miles away on the other side of a mountain even with his funky antenna mounted on the top of a pole.

 

I don't run that way anymore so no suggestions as to a shop. Would suggest getting antenna system checked BEFORE spending money on a radio tune. A great radio with a poor antenna system will perform poorly. A average radio with a good antenna system will perform better.

 

I’ve heard the guy in west Memphis ain’t bad. No first hand experience though.

 

Try Chuck in Holliday Tn, exit 126. He will be able to come outside and test your antenna. Ray in West Memphis is a very good tech, but he doesn’t work outside on the vehicles and his help has retired.

 

Just whatever you do don’t get into an accident and screw it up for the guys like me running a day behind ya...

... there’s a shop at the West Memphis Petro.