A good introduction to CB's?

[TSGB]

Looking to install a radio in the Xterra before winter, but I want to learn a bit more about installation, operation, and how things function before I get started. Does anyone have some primer material?

From out derelict radio forum I've gathered a few things:


Antennas work best with ground planes, which won't be happening with my roof rack. I'll likely go with a fender mount.

Wilson antennas are best, 3' or longer.

Antenna cable should be a multiple of 3' long, and not coiled.

Taking the radio to a shop for peaking and tuning will ensure I get the most out of my system.



I'm currently considering a Uniden 520 Pro, as it seems to be a good entry-level unit in regard to features and price. Also, rumor has it that it's similar to some Cobra radios that have to potential to be modded to around 18W, far beyond FCC maximum. While I'm unlikely to need that, I find it interesting, and wonder if it indicates the unit is over-built and hence more reliable.


Any input?

 

[Russell]

The length of / coiling of the cable does not mean that much. In theory, it does, but in real life you are much more likely to suffer interference from other electronics like the alternator.

Hook the radio straight up to the battery to help absorb noise. The battery is like a big capacitor that way. Ground planes do make a difference, considerably so actually, but a fender mount will do everything you can do with a CB at the moment. There is a lot of sunspot activity which makes HF radios like CBs next to useless for local transmissions due to all the skip they pick up. You'll have to compete with the retards with their big linear amps transmitting noise way off band.

I have always run a Uniden 510xl pro and always been happy with them. The only setting to mess with is the squelch to try and silence the skip and background noise.

Personally, I've all but walked away from running CB. Almost all of our local clubs are running VHF either on commercial bands or the HAM bands. Much better range, clarity and no problems with skip.

 

[Jagged]

Coax length only matters for loss and an impedance mismatch. A 1/4 wave ground plane antenna is 35 ohms or so. The smaller you antennas get... the lower impedance they are.

That's not too big of a deal, as you can use something called a tuner to do some impedance matching.

Your overall effectiveness of your antenna is its radiation resistance divided by the impedance. Now if the impedance is low because its a short antenna, and the antenna is mainly a giant coil (with a measure able resistance). Think about what that does for your radiation efficiency.

Back to the coax thing. You can do tricks with coax lengths to change the input impedance given a mismatch at the other end. But that trick only works at one frequency. Even venturing a few kHz away changes the impedance due to the change in wavelength.

In a nutshell, you want the longest physical antenna you can support (up to the 1/4 wave whip). You want it on a good ground plane. If the ground plane continues above the feed point, your pattern is not omnidirectional. Use an antenna tuner to match your system. MFJ makes one that you could bolt to a panel somewhere. Use the best coax you can get in the shortest run possible. 4W isn't much to begin with, and you don't want to lose 0.5W because you're trying to use exactly 18' of cheap coax because the internet says so. Use quality connectors and mounts. If you're spending money for a radio shop to tune up the radio, you can spend a few bucks for some nice amphenol connectors.

You may need to get some shielded spark plug wires, and clean up your charging system to reduce noise as well.

If you have any questions. Send me a PM, I'm not checking the forums much these days, but a PM will go to my email.