CB for You & Me by Brian Green N6HWY "Break one-nine for the Jolly Roger. This is the Wolfhound frying." It was the beginning of a new era; we were coping with an energy crisis. Gas and heating oil prices doubled, lines formed at gas stations and the speed limit was lowered to 55. So much for the negative. The up side was that we learned to conserve, started to explore alternative energy and everyone discovered citizens band radio (CB). Truckers had been using CB for years. It wasn't until the gas shortage that "Joe Lunchbucket" began to take an interest in this cheap, effective means of radio communication. With a CB radio, anyone could find out which stations had fuel, where the highway patrol was lurking, or could just carry on a conversation to make the miles go faster. CB is fun, where else can a grown adult call himself "The Rubber Duck" and get away with it! CB started out as low cost, two way, short wave radio communication. In 1958, the Federal Communications Commission (FCC) created CB from the 11 meter (27 MHz.) amateur radio band. Twenty-three radio channels (frequencies) were allotted to CB. On January 1, 1977, CB was expanded to 40 radio channels. Once the gas crisis was over with in the early '80s, the CB boom was bust and the dealers couldn't give the radios away. Government sponsored renewable energy projects were abandoned. Alternative energy forged ahead with or without tax credits. I'm sure that many folks have CBs stuck up on shelves. Those that don't have a rig around can buy one cheap enough ($50 to $150) at department stores. Now is a good time to start planning a worthwhile Spring project. Get a rig on the air and find out what is happening in your neighborhood. Leave a note on the local bulletin board telling people of your radio interests and what channel you monitor. Listen around on your CB, there may already be a local neighborhood channel. CB was designed to use short ground wave radio propagation, which is more or less line of sight. These RF or radio frequency waves travel in a fairly straight line near the ground, from one transmitter to another receiver. Maximum range for the average CB radio is about 25 to 75 miles, and depends on terrain and antennas. One of the drawbacks of CB at his present time is that we are heading for a peak in the 11 year sunspot cycle. The increased solar activity ionizes the upper levels (between 50 and 250 miles above our surface) of the Earth's atmosphere. This makes these layers reflective to certain wavelengths of radio waves. When the ionosphere becomes reflective, your four watt CB transmitter can travel (skip) over 2,500 miles. This causes a problem, since you can hear at least 1001 stations, all trying to use the same channel at the same time. The good news is that after Sundown the atmosphere cools off and the skip generally fades. Get It Together and on the Air If you are going to get a CB on the air, here is what you need. A RADIO. Use a 40 channel type because the 23 channels radios are no longer legal with the FCC. A POWER SOURCE. The can be directly off your 12 Volt battery or via a power supply. A power supply converts 120 vac in 12 VDC if your don't have it readily available. COAXIAL CABLE. This feedline is the connection from your radio to its antenna. Coax has a center conductor surrounded by insulation, over this insulation there is a copper braided tube. Over the copper braid there is a waterproof vinyl jacket. The center conductor carries the signal and the shield braid keep this signal within the coax until it reaches the antenna. Radio Shack sells CB coax, Part # 278-1328 at 21¢ per foot. This a low loss 52½ coax and comes with or without connectors on its ends. I prefer the RG8X type because of its small size and flexibility. ANTENNA- the center insulator. The center insulator (see photo #1) of your antenna can be made out of a number of nonconductive materials, including 1/4" plywood. If you use plywood, give it a couple of coats of water proofing shellac. I used a piece of 1/4 inch thick plexiglass I found at the dump. INSERT PHOTO ANTENNA- Wire Almost any copper wire will work. 12 or 14 gauge is a good size. Even the stuff you can get at the auto parts store in a 35 foot roll will do the job. Leave the insulation on except where soldering is required. Electric fence "egg" insulators, attached to the ends of the wire will insulate your antenna from the cords used to secure it. Photograph 2 shows how to pig-tail the coax. A bit of silicone sealer is used to keep water from getting inside the coax. While the silicone is still tacky, wrap the coax with black tape as seen in the photo. INSERT PHOTOS Photograph 3 shows the steps involved in trimming the end of the coax to accept the PL 259 connector that screws into the back of the CB radio. Once you have reached the fourth step (far right), the coax's copper braid will show through the holes in the body of the PL-259 connector. This needs to be soldered quickly with a high wattage soldering iron so that the insulation within the coax is not melted. Checking Out your Antenna's Site Things to think about: Where is the radio going to live? How long will the power lines to the radio be? Where is the antenna going to be erected? Where should the coax enter the house? How long of a coax run is needed? Try to keep the coax as short as possible to minimize losses. Building the Antenna If you are like me, this is the fun part. I'm only going to describe a simple dipole antenna. It will get you on the air for very little money and effort. If you don't like to build your own and are flush, then Radio Shack has a good base station antenna for $79.95 (Part #21-967). I'm not going into the theory of antennas. If you have an inquiring mind, see the list of reference material at the end of this article. The half wave dipole consists of two pieces of wire each 1/4 wavelength long. There are insulators at the ends of the wire and one in the center mechanically joining the two wires. CBs operate from 26.965 Mhz. to 27.405 MHz. The center frequency of the CB band is 27.185 MHz. Therefore, (just trust me on this or take a short course in antennas) the combined length of both pieces of wire is 17.22 feet. This is 17.22 feet from end to end of the antenna. The feed point is at the center and each of the two wires making up the dipole is 8 feet 7 inches long. These length figures are strictly ballpark. I've had antennas tune up perfectly at this length & others need a bit of trimming. Always leave a little extra wire on the dipole elements for trimming. The dipole can be put up vertically, horizontally or in an "inverted V". INSERT ILLUSTRATION Tuning your Antenna I built an inverted V dipole antenna. Two 10 foot sections of Radio Shack antenna masting where get the antenna into the air. The center insulator was tied to the top of the mast. The mast was secured to the ground by hose clamps and a firmly planted T type fence post. A T post at either end of the antenna provided a place to tie down the nylon cords attached to the egg insulators at the ends of the pieces of wire. INSERT ILLUSTRATION I used a standing wave ratio (SWR) meter to measure the forward and reflected power in the antenna. The SWR meter allows you to tune the antenna for proper performance. If the wires that make up the antenna are too long or too short, then the antenna will reflect the RF energy back to the transmitter rather than radiating it. The basic idea is to have all the CB transmitter's power radiated by the antenna rather than reflected back to the transmitter. If somebody in your neighborhood has an SWR meter to lend you, then fine. If not, Radio Shack sells one for $18.95 (part # 21- 525). I leave my SWR meter in line all the time so I can see if everything is working properly. With the radio all hooked up, I inserted the SWR meter in the coaxial line to the antenna. The moment of truth! I turned the radio on and lots of signals where coming into the receiver. The Skip was howling like a banshee. Well, I knew it would receive but would it transmit on my homemade antenna? I set the radio to channel 19 (the middle of the CB band), selected forward power on the SWR meter. I keyed the microphone to transmit and adjusted the sensitivity knob clockwise until the meter was indicating full scale. Next, while still transmitting, I selected the reflected power reading on the SWR meter. Not bad, my home made antenna has an SWR of 1.3. Anything less than 2 is acceptable. I checked the SWR on channels 1 and 40. This step is important because it tells us if the wires in the dipole are too long or too short. If the wires are too long then the SWR will be lower on channel 1 than channel 40. If the wires are too short, then the SWR will be lower on channel 40 than on channel 1. In my case, the SWR on channel 1 was the same as on 40, so I didn't need to trim the wires. If your antenna is not balanced like this, then add or remove 1/2 inch bits of wire from the ends of the dipole. If the lengths of wire are correct and you still have some SWR, then another way of reducing SWR is to change the angle at which the wires meet. I my case, I reduced the angle of the wires from 120¡ to about 100¡. This brought the SWR of the antenna down to 1.25 on channels 1 and 40, and to 1.2 on channel 19. I never cease to get a charge when a new antenna flys off the workbench. If you have any questions or experiences to share drop me a line. I'll do my best to answer your questions or point you towards a good source of information. Operating your CB The first rule of radio courtesy is to listen before you transmit. Only one person can transmit on a channel at a time without having chaos. So give others their chance to talk, just as you want yours. Channel 9 is reserved for emergency use. In some neighborhoods channel 9 is used as a calling channel. This means that after making contact the stations IMMEDIATELY move to another channel to talk. This allows everyone in the neighborhood to monitor channel 9 all the time and increases the chance of an emergency call being heard. Some Good Antenna Reading Simple Low Cost Antennas for Radio Amateurs by William I. Orr W6SAI & Stewart D. Cowen W2LX, Radio Publications Inc., Box 149, Wilton, CT 06897. $5.95 ARRL Antenna Handbook, American Radio Relay League, 225 Main St. Newington, CT 06111. Heavy on antenna and feedline theory $5.00. 73 Dipole and Longwire Antennas by Edward M. Noll W3FQJ, Editor and Engineers, Howard W. Sams Co. Inc, Indianapolis, IN 46268. Well, enjoy talking to your neighbors on the CB! If you're around Interstate 5 and the California/Oregon border you can call Home Power People on channel 9 CB, call for Wolfhound, Jolly Roger, FourTrax, Pennyroyal, and/or Oilburner, if you're a Ham, call on 146.400 MHz. Simplex for N6HWY, N7BCR, and/or KF6HG. You can write me at 13109 Norman Drive, Montague, CA 96064. 73s Bri