29 879
modifications
Modifications
Sauter à la navigation
Sauter à la recherche
Ligne 147 :
Ligne 147 : − + Ligne 157 :
Ligne 157 : − + − + + + + + + + + + + + + + + + + + + +
→What is SWR?
=== What is SWR? ===
=== What is SWR? ===
SWR (''Standing Wave Radio'') measure the performance of signal emitted in the atmosphere.
SWR (''Standing Wave Radio'') measure the performance of signal emitted in the atmosphere. This value is available on the antenna technical datasheet or can be evaluated with appropriate measurement device.
On a radio board, the signal is generated by the transceiver, flowing into the antenna cable and finally through the antenna to be emitted into the atmosphere.
On a radio board, the signal is generated by the transceiver, flowing into the antenna cable and finally through the antenna to be emitted into the atmosphere.
The worse case is when there is no antenna, in this case, the rejection ratio is 100%. Nothing is emitted to the atmosphere and all the signal is send back to the transceiver (which may possibly destroy it!
The worse case is when there is no antenna, in this case, the rejection ratio is 100%. Nothing is emitted to the atmosphere and all the signal is send back to the transceiver (which may possibly destroy it!
{| class="wikitable" border="1"
|-
| align="center" | SWR
| align="center" | Description
|- style="font-size: 90%"
| align="left" | 1.0-1.5
| align="left" | The ideal range! an SWR under 1.5 is really great. Getting under 1.5 (closer of 1) is possible but difficult, you may consider additionnal tuning, other equipment and different mounting location. However dropping under 1.5 (to 1.0) would not increase the performance in significant manner.
|- style="font-size: 90%"
| align="left" | 1.5 - 1.9
| align="left" | 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. Going to from 2.0 down to 1.5 will really offer noticeable performance improvement.
|- style="font-size: 90%"
| align="left" | 2.0 - 2.4
| align="left" | 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. It's by no means a good tuning job, but will function if you've exhausted all other troubleshooting possibilities.
|- style="font-size: 90%"
| align="left" | 2.5 - 2.9
| align="left" | 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.
|- style="font-size: 90%"
| align="left" | 3.0+
| align="left" | 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.
|}
Learn more about [https://www.wearecb.com/what-is-swr.html SWR on wearecb.com].
Learn more about [https://www.wearecb.com/what-is-swr.html SWR on wearecb.com].