In these days of cell phones and e-mails, it’s easy to overlook the valuable communication tool sitting right at your fingertips – your CB radio.
Citizens Band Radio channels are used for two-way, short-distance communications. Citizens band radio, or CB, as it is commonly known, was initiated in the United States in 1947, when the Federal Communications Commission (FCC) opened the UHF (ultra high frequency) 460-470 MHz band to licensees from the general public. In 1958 the FCC reallocated part of the 11-m band (27 MHz) previously shared by amateur radio and industrial users to the Citizens Band Service. By the early 1980s more than 20 million CB sets were operating on 40 channels in the U.S. However, the CB fad was waning by that time and in 1983 the FCC ceased requiring licenses for CB operation. At present CB users consist of truck drivers, recreational vehicle users and folks seeking to communicate with others within a limited range of distance. CB radio channels are open to all citizens.
"In these days of cell phones and email, it's easy to overlook the valuable communication tool sitting right at your fingertips- your CB radio."
Remember the fast action highway movies when everyone had a CB radio, a call sign and a friend zooming alongside playing the red herring to outfox the police? Those movies spawned a craze as frenzied as rock and roll, and it wasn’t long before everyone had towering antennas swaying from their vehicles or house tops and the country started communicating like mad. Of course, the airwaves became jammed and bridge clearances were a concern, but it was a unique opportunity for travelers and locals to briefly meet over the air and discuss the latest politics and weather. Most of us avoided the mad rush and preferred to stay out of the heated debates. Those CB radio fanatics have now replaced their antennas with laptops and turned their attention to Internet chat rooms. The CB channels have reached a peaceful calm and now is the time to tune back in.
Operation of the CB radio is simple. The radio has an off/on/volume control switch. It must be turned on and the volume adjusted to a comfortable hearing position. It should be noted that volume control deals with hearing and has no effect on the transmission level.
Next, there is the squelch control. This control is first turned up to a point where static or background noise is heard and then reduced to a point where the static disappears.
The channel selector is used to select the channel of operation (1 through 40). Channel 19 is the principal location used by most travelers and is helpful in monitoring information concerning traffic delays, construction, lane closures, etc. An undesirable effect of monitoring this channel is the language sometimes heard. CB radio users are generally courteous and polite, but there are always exceptions. When traveling with others, it is wise to use a channel other than 19, to allow for conversations without interruptions.
The radio microphone enables you to monitor traffic conditions without requiring a reply. If you want to transmit your own message over the CB radio it will be necessary to take hold of the microphone and depress the switch located on the side. Once the switch is depressed the radio converts from a listening device to a transmitter and anything spoken into the microphone is transmitted from the radio over the channel selected. To carry on a conversation it must be remembered that after each transmission the push button switch must be released to return the radio to receive mode. The radio cannot listen and transmit at the same time. Conversations should be brief as only one radio can occupy the airwaves at one time.
"The CB radio is a low powered transmitting device that works well within a line of sight of the person being spoken to."
Turn on the CB radio when you head out for the day and leave the radio on until you park for the night. Some of the more obvious reasons to do this would include having other travelers alert you to a baggage compartment door being left open or coming open during transit, the entry step being out, a low tire or problems with your tow vehicle. In return, you will be able to alert others about vehicle problems you yourself spot, or potential road hazards you pass.
The CB radio is a low powered transmitting device that works well when within a line of sight of the person being spoken to. There are many factors which limit the range of the CB radio such as terrain, trees, other vehicles and weather conditions. The radio itself, as well as the type of antenna used (see picture on page 27), plays a hand in determining the distance of receiving and transmitting. As was noted previously, only one radio can occupy the airwave at one time and consequently the radio with the greatest power and best antenna will always overpower the weaker one.
Other factors that enhance or detract from the effective range are the environment that the CB is used in, interference from other CB radios, tall buildings and trees. Certain atmospheric conditions such as pollution and haze can also limit the effectiveness of your CB radio.
If we were able to eliminate all negative environmental factors, a properly set up base station could transmit 10 to 15 miles, a mobile unit 5 to 7 miles and a hand-held unit approximately 2 miles with the only variable being the type of antenna used with your unit. Of course, these optimum conditions rarely exist and the range of your unit will be less depending on the conditions you are operating in.
All CB radios transmit using the maximum FCC allowable power output of four watts. The amount of power is determined by the type of antenna used, condition, location, the physical length of the whip—and more importantly—the proper matching of the standing wave ratio, or SWR.
To get the maximum use from your CB radio, always purchase the best antenna you can afford. The caliber of your antenna will influence the performance of your CB radio.
"During severe weather the... forecast is interrupted with special warning messages."
The primary consideration when preparing to purchase your antenna is the intended location of the antenna on your motorhome. You are not limited in where to place the antenna. Available are antennas that mount to the roof gutter, vehicle bumper, mirror, etc. With a magnet mount the antenna can be put on any metal surface of the vehicle body. If you don’t have the option of attaching the antenna to a metal surface it is sufficient to use a groundless plane antenna which is designed for special applications where grounding the antenna is a problem.
Antennas are available in a variety of sizes and shapes. Your objective is to obtain the largest possible range of transmission. In order to achieve that goal you will need to determine the length of your antenna, because the length of the antenna whip determines the range received. However, keep in mind that the longer lengths of 102 inches are generally not practical for a motorhome.
"Don't let your CB radio gather moss, use this... communication tool to enhance your motorhome travels."
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A center loaded antenna is recommended for mobile radios equipped with weather reception. A dual band antenna works fine for good weather reception and regular CB distance. If you’re interested in distance only, a base loaded antenna is sufficient.
Imagine the wings of an eagle gracefully flowing up and down as the majestic bird takes flight. This swooping wing movement is identical to the transmission waves exiting from your antenna and is called Standing Wave Ratio (SWR).
In order to set the Standing Wave Ratio—or SWR—on your CB radio, you will need either a CB radio with a built-in SWR meter or an external SWR meter. External SWR meters are available at electronic supply stores. Alternatively, your local service repair shop may have an external SWR meter for your use. Using an external SWR meter will also require a short piece of coaxial cable with CB-plugs on both ends. Attach the external SWR meter per the instructions included with the meter.
After properly mounting and grounding your antenna, position the motorhome in an open area away from obstructions. Turn off all appliances, electronics, air conditioning and furnace fans. Close all doors and windows. The SWR meter easily attaches to your radio.
Set the CB radio to the CB mode and tune to channel 20. Push and hold the “push to talk” button on your microphone. This will cause the SWR meter’s needle to swing to the right. By turning the knob adjust the needle to the calibration mark on your meter.
A reading of 3 or above will impact the performance of your radio and should be adjusted downward. A reading of 1.5 is average and acceptable under most conditions. A reading of 1 is ideal.
To reach the optimum setting it may be necessary to extend or retract the antenna whip. Move the antenna in small increments while repeating the procedure after each change until you reach the best setting you can. If you have to retract the antenna to get a better reading it is acceptable to clip the whip in small increments to obtain the proper length but try to avoid doing so as many antennas have adjustable rings to set the SWR.
Check the SWR reading on channel 40 and channel 1. If either of these channels is above 1 to 3.0 you may want to adjust the antenna so that you have an acceptable SWR setting for that channel while maintaining the lowest reading possible on channel 20. It is important to note the adjusting for the optimum SWR setting on one channel will affect the SWR setting of another channel on the other side of the dial. Thus if you optimize channel 1, channel 40 will suffer. Try to get the best you can across all channels.
If you cannot obtain an acceptable reading, recheck the antenna mounting and more importantly grounding of the antenna. It is extremely difficult to get an acceptable SWR reading without a properly grounded antenna.
Weather Alert is a unique feature that alerts users of a weather emergency as defined by the National Oceanic and Atmospheric Administration of the U.S. Department of Commerce commonly know as NOAA.
NOAA maintains a system of approximately 380 stations throughout the United States that transmit continuous broadcast of the latest local weather conditions 24 hours a day, 7 days a week. The broadcast is made on one of seven high band FM frequencies and are tailored to suit the local needs of its listeners.
During severe weather the normal NOAA forecast is interrupted with special warning messages. At this time NOAA will transmit a 10-second signal which can be picked up by CB radios equipped with the Weather Alert feature. This signal can be picked up whether the radio is turned on, off or on in the CB mode. During the transmission of a weather emergency the radio will emit a high pitched tone to alert the user to tune to one of the weather channels to listen to emergency information. It is normal for a Weather Alert CB radio to beep for a second when the unit is turned on or when power is first applied to the unit. This is only a self-check tone.
Channel 9 is the universal emergency channel and should never be used for normal communications. Channel 9 is monitored by state patrols, local police and citizen volunteer groups who will assist you in your call for distress.
Because the CB radio is open to all users, it is imperative that rules of common courtesy be applied in order to make the system work for everyone. There will be exceptions to this rule, but you can do your part in keeping the airwaves friendly by following the basic rules of operation.
You are not allowed to carry on a conversation with another station for more than five minutes at a time without taking a one-minute break for others to use the channel.
You are not allowed to blast others off the air with illegally amplified transmitter power or illegally high antennas.
You cannot use the CB to promote illegal activities, use profanity, play music, sell merchandise or professional services.
Don’t let your CB radio gather moss, use this powerful communication tool to enhance your motorhome travels.
Shelly Floyd is a freelance technical writer based in Eugene, OR. She specializes in RV-related subjects and is a regular contributor to Lifestyles and Holidays magazines.
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