I had a lot of question regarding CB radio for primary preparedness communications. CB radio can certainly work but can be very limited and even frustrating depending on your environment, time of day and sunspot cycles. I've written an article to address these questions and thought it may help others here that may be trying to decide what direction to go in when it comes to comms.
Things to consider when using CB radio as a primary communications method for emergency preparedness. There are many variables in radio communications. Each radio service has it's own pros and cons. These pros and cons need to be assessed and understood in order to get a good mental picture of what is the best for you and your needs. There are two sides to these pros and cons that you need to understand. There is the legal side...which is the licensing (on radio services that require it) and how the licensing structure and rules are setup...ya know, what are the restrictions and limitations of the radio license (very important) and then there is the radio service's frequency characteristics or "personality". By "Personality" I mean different frequency ranges (bands) have different traits. Low frequency bands have better propagation (range), longer wave length which translates to longer antennas which usually means far less absorption by natural obstacles such as trees, foliage and hills sides but tend to be more susceptible to electrical noise where as higher frequency bands have less propagation and are less susceptible to noise and better for man-made material penetration..particularly UHF (400-500Mhz) and higher frequency bands.
CB radio has its ups and downs as well. The up side is that CB radio is lower in frequency which means it has the potential to go further. It also doesn't require a license, the radios are cheap and available almost anywhere. The down side...well you might want to sit down, throw on a plaid shirt and get a cup of coffee for this. Since it's licensed exempt (doesn't require a license) and unregulated it tends to be a "free-for-all" band. Legally it's suppose to be limited to 4 watts of output power. Since it's unregulated a lot of folks use linear amps to boost power well above 150 watts. Since CB radio is AM and the entire CB radio band is only .440Mhz or 440Khz (less than one half of 1Mhz) in bandwide there's only a tiny 10 Khz of space between each channel. This means that anybody talking in the CB band with a LEGAL radio using as little "modification" as an aftermarket power microphone can "splash" over from other channels making it difficult to use the radio to talk to others more than a few miles away. When a “linear” amplifier is used the “splash” is FAR worst. It's not uncommon to hear this "splash" ten channels above and below the channel where this illegal user is actually transmitting from. For example: The person is transmitting on channel 10 but can be interfering with every channel down to channel 1 and up to channel 20!
The characteristics of the CB radio band...since it's actually in the HF or High Frequency portion of the spectrum (which is very low in frequency in comparison to other radio services) SHOULD have great distance/propagation...but it suffers from two big issues. It's AM (not FM like most other radio services) which means it's very susceptible to electric noise (lightning, power lines, alternator wine, etc) but in this frequency range it's also vulnerable to atmospheric issues such as the sun spot cycles and tends to be much better for night time communications rather than day due to this trait. Combine that with the CB communities often, almost competitive nature of communicating - it's a tough band to get behind and consider for any investments.
The other major down side is trying to use CB radio in a portable format is horrendous. Since CB Radio is very low in frequency. 27Mhz. The wave length is very large which translates to the need for a larger antenna. Most antennas require a "counterpoise" or ground and a reflective surface called a ground plane. The issue is, by the time you take a large wave length band like CB...and squash that antenna down to a length that's suitable for a portable radio, you have lost nearly 90 percent of it's efficiency. If this isn't bad enough...there is virtually no ground plane surface what-so-ever on a portable CB radio, due to the massive size of what's required for a ground plane in this frequency range. So unless you're only using your portable CB radio at under 1/4 mile...outdoors it's almost useless.
Here is a video that was made to help PEG radio users understand the differences between higher and low frequencies bands but it does address these radio band "personalities", vehicle antenna placement, ground plane requirements and some other topics that provides some insight how the bands and the antennas for these different bands function. https://www.youtube.com/watch?v=9g8b4YHUDHc
I hope this sheds a little more light on the subject.
-Chris
CB Radio for Prepper comms
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