How is the SWR adjusted?
The object is to get the SWR the same on channels 1 and 40, and below 3. Whatever you do, make sure the SWR is below 3. Once the SWR is the same on channels 1 and 40 and is also less than 3, the antenna is tuned for optimum performance. Begin by checking the SWR on channels 1 and 40, then refer to the following: If the SWR is higher on channel 1, the antenna is too short. If the SWR is higher on channel 40, the antenna is too long. An adjustment is made to the antenna (refer to the antenna instructions), then the SWR on channels 1 and 40 is re-checked. This process is repeated until the readings are about the same. Remember that the readings must also be below 3. When you are done, check the SWR on channel 19. It should be even less than what you got on channels 1 and 40. Most antennas are adjustable. Refer to the instructions that came with your antenna or call the manufacturer. If you have dual antennas, make equal adjustments to both antennas. Here are a few methods, which vary with
