CB Radio Repair
Technical FAQ Top six questions asked. As of Feb 2009
Q: What should the SWRs be on my antenna system?
A: 1.5 or less, at 1.5 you are only reflecting 4% of the wattage back into your radio
Q: How far can I talk on my radio?A: It depends on your radio and antenna system they are both important. On average 5 to 10 miles. I live in a long valley with hills on either side, so most times we can talk about 12 - 18 miles within the valley. It is tough to get over the hills.
Q: I hear other people talking about getting their limiter cut, what does this mean?
A: A limiter is what controls the amount of modulation the radio can put out. It should be set for 95% to 100% on most radios, some style radios you can cheat with the modulation. It all depends on distortion (distortion is a measurement of audio quality thru the mic into the radio and transmitted from the radio, the lower the reading the better). I restore most cut limiters and re-align the radio!
Q: My radio squeals, what should I do?
A: This one can take up several pages so I will only talk about a few of the problems. MOST of the time a squeal is caused by the SWRs not being good enough (not necessarily high). Another reason could be is the external speaker is too close to the stock mic, if you use a noise cancelling mic it stops. On some of the newer radios if the SWRs are to high a capacitor blows in the final stage and this causes a squeal with everything else working.
Q: What is the RF gain on the front of most radios?
A: Simply put it is your receive distance, with a properly tuned radio and the RF gain all the way clockwise you will get the maxium receive distance for that radio and antenna system.
Q: What size fuse should I be using?
A: Depends on your radio. Ohms law states: I (amps) = P (max wattage) divided by E (voltage)
For example: If your max wattage is 50 watts then divide this by the voltage typically 13.8 volts which equals 3.6 amps or a 4 amp fuse. The problem most people have is what is the max wattage of my radio? Being that all CB radios are AM (amplitude modulation) radios we never know what is the max power because the power out is effected by how loud and the pitch of the voice going in. So with all that said I like to see the above formula used and double the results, so in this case double the 3.6 and use a 7 amp fuse, you would be right in the ballpark.