Tuning your antenna to an acceptable SWR is crucial for good performance. The guidelines below give you a sense of what SWR readings in each range mean, and how to deal with excessively large ones. For more information on what SWR is and means, please see our guide titled Understanding SWR.
SWR Range Explanations
SWR 1.0-1.5: The ideal range! If your SWR is under 1.5, you're in great shape. If you're at 1.5 and really, really want to drop down to closer to 1, it's likely possible to do with addition tuning, different equipment or a different mounting location. But the drop from 1.5 to 1.0 won't make a substantial increase in performance. It's not nearly as noticeable as, say, going from 2.0 down to 1.5.
SWR 1.5 - 1.9: There's room for improvement, but SWR in this range should still provide adequate performance. Occasionally, due to installations or vehicle variables, it's impossible to get SWR lower than than this. You should try to get it lower, but performance should still be acceptable in this range.
If you've tuned the antenna, SWR in this range is likely an issue of a less-than-ideal mounting location for your vehicle and/or an antenna that isn't ideal for the mounting location. To troubleshoot, see this article on problematic CB antenna mounting locations.
SWR 2.0 - 2.4: While not good, this likely won't damage your radio with casual use. However, you should definitely try to improve it if you can. SWR in this range is usually caused by a poor antenna mounting location and/or a poor choice of equipment for your specific vehicle. To troubleshoot, you'll likely need to move the mounting location and/or use a more suitable antenna.
Again, it's by no means a good tuning job, but will function if you've exhausted all other troubleshooting possibilities.
SWR 2.5 - 2.9: Performance in this range will be noticeably decreased, and you might even damage your radio if you transmit frequently and for extended periods. We advise you not to operate your radio in this range.
SWR in this range is usually caused by a poor mounting location and/or a poor choice of equipment for your specific vehicle. To troubleshoot, you'll likely need to move the mounting location and/or use a more suitable antenna.
SWR 3.0+: Performance will be severely affected, and you're likely to damage your radio with extended transmission use. You SHOULD NOT transmit with your CB at SWR levels above 3.0. If your SWR needle swings all the way to the right (off the charts) when getting your 3.0+ readings, you almost certainly have a major installation problem.
This is almost always the result of a poor ground or incorrectly assembled stud, but on rare occasions can indicate a faulty coax, antenna, or incorrectly attached SWR meter. To troubleshoot, please see our guide to Troubleshooting High SWR Readings.
IMPORTANT NOTE: Radio damage will only occur when you're TRANSMITTING from an antenna with high SWR readings. Leaving the radio on to receive signals poses no risk to your radio.