Setting up a CB Radio
From FogWiki
Here is a brief overview on how to set up your CB
Contents |
Basics
First thing to do is make sure you get a good power supply to the CB. Do not take a power feed from your radio circuit!. This can lead to all sorts of problems, from blown fuses to blown CD/Radio players. Take a feed from as close to the battery as you can, but make sure it is fused! A normal 4w (legal) CB shouldn't need any more than a 5 amp fuse. Keep the power feed away from the ignition/HT circuits of the car, otherwise you will find you get engine whine on the CB, which at best is annoying, at worst will make the rig unusable while the engine is on.
If you are using a fixed mount for the aerial, make sure that the mounting has a good connection with the metal you are attaching it to. If this is the bullbars for example, make sure as well that there is good connection between the bullbars and the chassis. Paint will stop conduction, so it is important to find somewhere you can get a good contact between the mount and metal.
If you are using a magmount, make sure you regularly take the mount off the car and clean the base.
Check the coaxial cable all the way from the aerial mount to the CB, ensuring there are no nicks or kinks in the cable, as this can be a sign of the inner core being broken, which will cause problems.
SWR/Tuning
SWR (Standing Wave Ratio) is important to your setup, as it is a measure of the power being reflected back into your CB .. which as you can imagine can be a bad thing. To alter your SWR is a matter of "tuning" your aerial, normally by undoing a little grub screw at the bottom and moving the whip part of it up or down accordingly.
To tune, make sure you get readings on three channels - one on the very lowest, one in the middle and one at the top. If you have an 80 channel rig, this would be channel 1 Mid band (often marked as "EU" on the switch), channel 1 UK and channel 40 UK - for a 40 channel rig then just channel 1, 20 and 40. Your aim is to get this to be as close to 1 as possible (i.e. the SWR meter hardly moves when in reference mode) on all channels.
Put the SWR meter inline, select the channel, put the SWR meter in "FWD" mode and transmit. Adjust the calibration knob until the needle is right at the top of the scale. Stop transmitting, select "Ref" mode on the meter, then transmit again - this will give you your actual reading. Repeat on all three channels (including calibration), and adjust as necessary
If the SWR is higher on the high channel, lower the whip - if it is higher on the low channel, raise the whip.
The chances of you getting a perfect 1.1:1 SWR across the board are slim, but anything below 1.5:1 would be normally acceptable.
Testing
Once you have gotten everything up and running, take the SWR meter out of circuit, tune to channel 19 UK and listen. If you can hear people using it, just wait for a break in the transmissions, "key up" (transmit) and just say "One-nine a roger!" ... if people can hear you, you will simply get a "roger" back at you - that will tell you all is probably good.
CB Lingo
Few people use the full lingo any more, but they will still use some. Here are some key phrases:
Rig check - This is asking for someone to tell you how well they are receiving you, both in transmitted power and audio quality ...
Giving me (number 1 to 9 or "thirty plus") - e.g. "Giving me 9's" - this is how the receive signal strength is measured. If you have a meter on the front of the CB, you will see it marked in numbers 1 to 9, then a green part at the end marked "30" or "30+". Don't worry if someone gives you a low number - try and find out how far away they are from you, as it could be that you are some distance and CB's (usually) only have a finite range. Some of the older CB'ers among us will also give you a full signal report along the lines of "9 over 5 Q radio 5" - this would be that your signal strength is between 5 and 9 (though closer to 9) and have a good clear audio transmission (the Q radio 5 bit). Voice/audio quality is a perceived scale of 1 to 5 - that is that 1 is poor, 5 is the best, and you use your own judgement as to what score you give.
Over modulating - This is where your microphone is too loud, and causing your peak transmit power to dip. Again, watching the meter on the front of the CB, you can tell if someone is "over modulating" as the signal strength will dip relative to the loudest parts of their transmission (sort of a reverse volume meter effect). If you are told you are over modulating - if you have a "Mic gain" control on the CB, turn that down a few degrees and try again - if not, then just move the microphone further away from you.
On the side or QSK - If you are scanning the channels and find a couple of people chatting, and for some reason would like to talk to them, wait until a suitable break in the transmission, key up and say "on the side" or "QSK" and wait to be acknowledged. Do not just barge in on a convo ... it won't get you very far.
Affirmative and Negative - (Sometimes "Affirmatory" and "Negatory") - Fairly obvious, but "Yes" and "No" respectively
Give me a 9 - A variant of the old "10-9" code - "Repeat last message", or in laymans terms "Say that again?!" (for a full list of the 10 codes, click here)
Key Channels
Channel 19: This is the "calling" channel. Try to avoid having a full blown conversation on this channel, regardless of how quiet it seems
Channel 14: Used to be the same as 14, but not any more. Still one I avoid out of courtesy.
Channel 9: Emergency channel. Avoid using this channel, as while it is mostly unmonitored these days, there are still clubs and groups around the country that monitor it.
Channel 8 (UK): FOG channel - Used on meets etc
DX'ing
At times through the year (normally on hot, moist days in the summer, but certainly not the only time) you might hear people "DX'ing" - i.e. using the atmospheric conditions (often called "skip") to extend the range of their transmissions, and talking all over the world (though it is usually Germany that comes through). There are a whole load of "Q" codes involved (full list here), as well as "QSL" cards that are exchanged to prove contact. If you hear someone shouting out for such a contact, I would advise that you just listen - it is often interesting, though again, often you will only hear one side of the conversation.
