The 29 LX has a built-in SWR meter that lets you lot check how well the antenna is tuned to the CB band. It is recommended to check the SWR on channels one, twenty, and 40. Please annotation that whenever you change the channel, you MUST repeat steps 3 - 6.

        i. Park at least 20 feet away from trees and buildings. Close all doors, hood, and body.

        ii. Choose the channel to check.

        3. On the radio, press the SWR/CAL button until the display says "CAL":

        4. While pressing the transmit push button on the microphone, turn the SWR CAL knob until the meter reads to the CAL                     mark. (the SWR CAL knob is the last knob on the correct)

        5. Release the transmit button, and so push the SWR/CAL button until the display says "SWR".

        6. Press the transmit button on the microphone, and then read the SWR on the top calibration of the meter. The SWR should              be beneath iii. The lower, the better.

What is SWR?

SWR is short for STANDING WAVE RATIO. It is a measure of how well the antenna is performing. Most problems with the antenna or antenna cable will show up during an SWR cheque.

Please annotation that the SWR is a measure out of antenna performance. A poor SWR is caused by the antenna, the antenna cable, or a poor antenna installation. Poor SWR is not acquired by the radio. Since the SWR is a role of the antenna system, changing radios will non touch the SWR.

Why is SWR important?

SWR readings typically have a range of nearly 1 through10. The lower the number, the better the antenna is working. Every bit the SWR climbs, both transmit and receive range volition drop. An SWR of 1 is perfect, only information technology is not possible to get a perfect reading on all forty channels. When the antenna is properly adapted, the SWR is will be highest at the ends of the band, and lowest in the middle (channel 19).

The SWR reading must never exceed 3, otherwise the transmitter in the CB radio tin can overheat and eventually fail. Excessively high SWR can also crusade other problems such every bit a squealing dissonance, or can crusade interference with other electronic devices in the vehicle. An SWR below 2 is very skillful, and anything below 1.5 is excellent.

How is the SWR adjusted?

The object is to get the SWR the same on channels 1 and twoscore, AND below 3. This is achieved past making small adjustments to the length of the antenna.

Brainstorm by checking the SWR on channels 1 and 40, and so refer to the post-obit:

  • If the SWR is higher on channel one, the antenna needs to be longer
  • If the SWR is higher on channel 40, the antenna needs to be shorter

An adjustment is made to the antenna, and so the SWR on channels one and 40 is re-checked. This process is repeated until the readings are about the aforementioned. Remember that the readings must also be beneath three. When you are done, check the SWR on channel 19. It should be fifty-fifty less than what you got on channels 1 and xl.

Well-nigh antennas are adjustable. Refer to the instructions that came with your antenna or call the antenna manufacturer. Here are a few methods, which vary with manufacturer:

  • Antennas with a steel whip are usually adjusted by loosening a ready spiral and raising or lowering the whip. If y'all have a center-loaded antenna (fat department in the centre of the whip), adapt the top whip up and down. Even if the instructions do not refer to raising and lowering the whip, nearly all whip antennas tin can be adjusted in this style.
  • Some models accept a metal collar on the outside of the antenna load (at the base of operations). The neckband is turned to arrange the antenna. This method is not widely used.
  • If you lot accept a fiberglass antenna and in that location are no visible means of adjustment, it can be adjusted every bit follows:
    1. Remove the plastic cap from the tip of the antenna.
    2. Slit the plastic embrace to betrayal the top coils of wire.
    3. To shorten the antenna, cut off the top coil.
    4. To lengthen the antenna, pull the top curlicue upwards.
    5. Supercede the plastic cap.

It is all-time if yous refer to the specific instructions for your antenna or call the antenna manufacturer. For instance, some fiberglass antennas have a sleeve which yous slide up and down to adjust the antenna.

If you cannot become the SWR beneath 3

The whip is too long (steel whip antennas)

If y'all have pushed the steel whip all the way down and the SWR is still higher on aqueduct 40, then the whip is too long. In this case, information technology is permissible to shorten the whip by cut the finish. If the whip is painted, scrape the paint away after cut so that there is skilful electrical contact with the ready screw. DO NOT cut more than 1/2 inch at a time. Before cutting, read all the way through this section.  Your trouble might be an installation problem, non that the whip is as well long.   Be careful! If you cut too much, you lot may wind upwardly with an antenna that is now too short.

The whip is likewise curt (steel whip antennas)

If you have raised the whip as high equally it can go and the SWR is still higher on channel ane, please contact the antenna manufacturer.

Very loftier SWR readings

If the needle is going all the style to the cal marker when you try to read the SWR, then the problem is either a damaged antenna cable or an incorrectly installed antenna.

  • On mirror-mountain installations, the antenna must NOT bear on the mounting bracket.  The antenna should spiral up confronting a plastic insulator. Make certain that the plastic insulator is in identify. If it is missing, the SWR volition be very high. You can notice replacement insulators at truck stops.
  • On bumper-mount antennas, the most common problem is the antenna being shorted to ground due to an incorrectly installed mount. This results in a very high SWR. Make sure that the mount has been properly installed, using the supplied plastic insulators. The best thing to do is disassemble the antenna mount, then carefully re-gather per the installation instructions.
  • The easiest manner to diagnose the antenna cable is to simply try a new one. You tin can connect it temporarily and run it through the window to the CB. If information technology solves the problem, and then install the new cable permanently.

If you have an ohm meter so yous can endeavor the following:

  1. Disconnect the antenna cable from the radio and measure betwixt the heart conductor and the connector trounce. There should exist NO continuity (you should not become a reading).
  2. If you do go a reading, then disconnect the cable from the antenna and echo the examination.
  3. If you still become a reading, and then the cable is bad. If you no longer get a reading, then the mount is installed incorrectly.

The SWR is a little over 3 on all channels

  • Mirror-mount installations must take skilful electrical contact with the frame of the vehicle. Try connecting a #12 ground wire from the antenna bracket to the door hinge.
  • Mounting the antenna to an aluminum surface (tool box, etc.) may not provide a good ground. This is because aluminum is not a good conductor. A grounding problem can besides occur if mounting to a luggage rack. Try running a #12 ground wire to the antenna bracket. If the SWR is still loftier, try relocating the antenna.

Wrong blazon of antenna

It is as well possible that you are non using the right kind of antenna. Most CB antennas must be mounted to a metal surface ("ground aeroplane") in gild to operate properly. The metal body of the vehicle serves this purpose. On fiberglass or plastic torso vehicles, a "no-ground-aeroplane" antenna is needed. This blazon of antenna is especially designed to operate without a metal surface.