*CB Radio...The basics*
...or...
What the hail are all these wires, knobs & gizmos??
And How do I put it together and make it work??
I'll start off with the assumption that nothing it connected to anything in your box of goodies and will discribe as best I can what you should be looking for & how it should function.
First lets look at the radio itself.
On the front you will see several knobs, switches, a meter or perhaps a small display area. Usually these are labeled {{{NOTE..the lable may have the whole word or an abbreviation as I indicated with CAPS}}} and will include: (ON/off VOLume) This knob turns the power on & off and also adjusts the speaker volume.
(SQueLch)
This knob will cut out noise and limit reception to stations that have the strongest signals.
(CHannel)
This is usually a larger knob used to select the channel to operate on.
These are the "basic" knobs on 99% of all CB's out there. Now on more elaborate units you will find more controls these may include some of the following:
(LOC/DX)
This switch is similar to the squelch control but cuts the incoming signal by a set amount. LOC means local and DX means distant. Once you're up & running a bit of experimenting will fill in any blanks but to start with leave it in the DX position.
(CB/PA)
This switch allows you to mount a loudspeaker under your hood so you can yell obscenities at idiots in traffic. IMHO totally worthless leave it in the CB position & don't bother with the loud speaker.
(AM/USB/LSB)
You might find this switch on some of the "higher end" rigs. What this allows you to do is select: (AM) or Amplitude Modulation which is standard on all CB's, (USB) or Upper SideBand, (LSB) or Lower SideBand. The sideband modes are great for working long distance "skip" stations but require someone else in the same mode. The use of sideband is an article in itself but feel free to experiment with it. Most sideband activity is on the higher channels (35-40).
(Delta Tune) or (Clarifier)
This knob will work in the USB or LSB mode to fine tune a distant station transmitting in the same mode.
(Mic Gain)
This knob allows you to increase or decrease the amount of audio signal your microphone puts into the radio. Too little and you wont be heard...too much and your transmitted signal will be garbled and distorted. Start at 50% and ask other stations how your audio sounds...with a bit of experimentation and the help of another station you'll find a setting that's best.
Meters, lights & displays:
Most rigs will have some type of meter or display on the front that will indicate incoming signal strength and relative power output. This is commonly called an "S Meter" Sometimes, instead of a meter, a rig will have a LED (Light Emitting Diode) bar in different colors for the same purpose. Low end rigs might only have a single LED thats green when recieving and red during transmit. Some of the higher end rigs may include an SWR (Standing Wavr Ratio) meter to check the efficiency of your antenna.
(MICrophone)
This will be a connector where the MIC plugs in. There are several types, sizes and discriptions. Some have 4 pins and some have 7-8 pins depending on what features can be controlled from the mic.
That about covers all the gizmos you'll encounter on the front of most CB's. I'm sure with the myriad of different rigs out there someone will come up with something else but chances are it won't have much effect on the general operation of the radio and a bit of experimentation will answer your questions about it.
OK....Flip the radio over & have a looksee at the backside.
Here you will find power cables, antenna connections & maybe a couple other audio plugs. Here's what they're for:
(ANTenna)
This is the connection point for your antenna. I will be about 5/8 inch in diameter, threaded on the outside & have a small hole in the center. It's probably the largest connector on the back. I'll get to more about antennas a bit later.
(PoWeR) or (DC in)
This is the hookup point for power to the radio. Sometimes there will be a couple wires permenantly mounted and on other rigs there will be a socket for a particular plug. Lets start with permanent wires. >>>>PAY ATTENTION HERE FOLKS<<<<<<
You should have TWO wires...One will be RED and the other will be BLACK.
The RED wire MUST go to the POSITIVE (+) terminal on your battery or power supply and the BLACK wire MUST go to the NEGATIVE (-) terminal. NEVER NEVER NEVER get this reversed...you'll cook the radio!!!!!
Some radios have a "socket" instead of permanent wires. There "should be" a plug included that fits this particular socket and it will have red & black wires to be hooked up as shown above. In many instances the socket will be labeled showing which pin is positive and which is negative. If you find yourself in a situation where there's no plug and no diagram then post a question on the commo board & I'll explain how to figure it out with an ohm meter or continuity tester.
You might see a couple more small sockets on some rigs to wit:
(EXTernal SpeaKeR)
This will be a small socket where you can hook up an external speaker for better audio quality when recieving.
(PA)
This is for the ole under the hood "loud hailer" I mentioned earlier. I'm sure it has applications but I don't use the feature & it has no effect on the general operation of the radio unless ya need it for a cheapo Public Address rig.
That about covers the "hoo-hars & thingies" you'll see on the back. On some modles there may be "cooling fins" also known as "heat sinks", Ya might see some surface mounted transistors but ya don't need to concern yerself with these.
So theres a rundown of what ya might expect to see on any given CB...some have more, some have less but I "think" I have got all the important aspects covered.
Now let's look at some of the attachments you will be using.
Microphone.....
Mic's come in all sizes & discriptions and will have a plug to attach it to the radio. Some just "plug in" and others have a (screw on collar). Many radios will not function at all without the mic attached so make sure it's hooked up when you get to the testing phase.
All mics will have a Push To Talk (PTT) switch. This is usually a large bar on one side of the mic. Depress this to talk and release it to listen.
Some mic's have other features like (UP/DOWN) buttons on the top to change channels & some have a (mic gain) slide control. Once you've got the rig hooked up and running a bit of experimenting will answer those questions.
Antenna.....
This is probably the most important part of ANY communications radio!!
There have been volumes written about antennas and different designs etc, etc, etc. I'll state here that "A cheap radio with a good antenna is much better than an excellent radio with a POS antenna" DON"T cut corners or try to save a few bux here.
Some antennas are made to mount on truck mirrors, some are to mount on a trunk and others have a big magnet in the base to attach to a metalic surface. The magnetic mount type is very common so I'll go with that type but ALL are similar in operation. The differences will only be in how they are attached to the mounting surface.
Power Source.....
There are many usable power sources for a CB. ANY "CLEAN" 12 volt source rated at 5 amps or more will do fine. By "clean" I mean filtered to remove any hummmmmmmmm from an AC (Alternating Current) source. AC is what most homes are wired for and wall recepticles are running at about 117 volts so DONT TRY TO HOOK A CB INTO THE WALL SOCKET!!!!!
Examples of a GOOD CLEAN POWER SOURCE:
A 12 volt car battery.
A "Filtered" Power converter (available at radio shack).
A solar panel rated for 60+ watts in bright sun.
Examples of BAD power sources:
A battery charger (unfiltered)
Small "wall wart" power transformers (unfiltered and not enough output)
A vehicle alternator (most are unfiltered)
These are OK for recharging a battery but for reasons stated I find them unacceptable as a direct source of power for commo gear.
Now FWIW a bit of advice here....Before ya start drilling holes in your vehicle & "hard mounting" everything...TEST IT FIRST!!!
OK...Lets start "hooking stuff up"
Now I don't know what you may or may not have for a "power source" but it's reasonable to assume most of us have some type of vehicle & that it's got a decent battery under the hood so I'll go with that premise.
Open the hood & locate the POSitive (+) and NEGative (-) terminals on your battery. If you need any help here ask your local backyard mechanic for a hand....Recall my earlier cautions please!!!
You DO NOT need to have the motor running.
Find a place on the fan cowling or whatever is convenient to set the radio. Make sure the microphone is plugged in. Attach the antenna to the back of the radio and set the antenna on the roof of the vehicle (there should be ample wire on the antenna to do this. Make sure the radio is turned OFF (usually by turning the volume knob all the way to the left or counterclockwise until you hear or feel a little click) Attach the BLACK WIRE to the NEG (-) battery terminal and then take the RED WIRE and touch it momentarily to the POS (+) terminal. You SHOULD NOT SEE OR HEAR ANY SPARKING or noise from the radio. If you do...look things over and mak SURE the radio is off and that you have properly identified the battery terminals.
OK...So Far So Good.
Attach the red wire to positive and turn the radio ON. Set the volume about half way and turn the squelch knob all the way left or counterclockwise. Now you should be hearing some noise... If not...look at the front of the radio...are there any lights lit?? Is there a PA switch in the wrong position? Is the microphone securely plugged into its socket?? Triple check your wiring to the battery. Usually there is a fuse in the red wire and sometimes both wires. Check these fuses and replace if necessary with the SAME SIZE fuze...don't get cute & wrap it with tinfoil...you'll be sorry!!
So we got all kinds of noise...fine...start going through the channels & see if anyone is talking. Channel 19 is a common "truckers" channel so it's a good place to start. Tinker with the knobs & switches & see what they do you're not going to hurt anything so check 'em all out.
Now it's time to see it the rig will transmit. If you have a friend or neighbor or team mate that has a CB then give them a phone call and decide what channel you'r both going to be on for the test...If no one is available then go to channel 19, press the PTT button on the mic & say (BREAK 19 FOR A RADIO CHECK) Try not to interupt anyone else while theyre takling. You should hold the mic about an inch from your mouth and speak in a normal tone.
Keep trying for a "radio check" every few minutes until you get get an answer like "GO AHEAD RADIO CHECK" Now you can converse with this "contact" just remember...push to talk and release to listen.
CONGRATULATIONS....YOU'VE DONE IT.... HAVE A BEER TO CELEBRATE!!!!
So now you have yourself a working CB...I guess the next question is: Where do you want to mount it?? Will it be permanent in the vehicle, easily removable to put into another vehicle, used in the house or retreat or some combination of the above?? Due to the differences in vehicles there are way too many mounting options to discuss but it should be in a location that will not interfere with operation of the vehicle or block any controls. Power should come directly from the battery and BOTH wires should have a fuze located as close to the battery as is possible.
The question has been raised about using a mobile radio in a house or other location OUTSIDE a vehicle...Can this be done??? YES...of course it can.
Just remember to use a CLEAN power source and if you have a magnetic mount antenna you can put it on the top of a refridgerator or other fairly large flat metalic surface. The "mag mounts" need a flat metalic base to act as whats known as a "ground plane" The efficiency will suffer somewhat but it will work. "BASE STATION" antennas are much better but also cost more and need to be mounted on the roof or tower so all these things need to be taken into consideration.
There is one other area that needs to be addressed and that involves checking the SWR (Standing Wave Ratio) of whatever antenna you are using. Most folks don't have an SWR meter so you should ask around & try to locate one. If you're on good terms with a clerk at the local radio shack or other electronics store perhaps you can get them to test it for you. In low power transmitting such as in the CB bands you will not likely damage your radio with a bad SWR but the efficiency of our output will suffer so I recommend you get this checked and adjusted if necessary. In Amateur Radio where rigs run 100 to 1500 watts output a mismatched SWR can cause all kinds of burned out componants.
Well I guess that about sums it up. I'm sure there are going to be some questions arise due to the many different radios, antennas and associated gear on the market as well as methods of mounting and making it portable for field operations etc....Please post any questions, concerns, comments etc on the "Communications Board" and I will help as best I can. ALSO...Read through the other fine articles in the files section. Theres a ton of great stuff there & it's getting better every day.
Be Good...Be Careful...& enjoy your new commo skills.
JW
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