The 29 LX has a built-in SWR meter that lets you cheque how well the antenna is tuned to the CB band. It is recommended to check the SWR on channels 1, 20, and forty. Please note that whenever you modify the aqueduct, you MUST repeat steps 3 - 6.

        ane. Park at least twenty feet away from trees and buildings. Close all doors, hood, and trunk.

        2. Cull 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 push button, so push button the SWR/CAL push until the brandish says "SWR".

        6. Press the transmit button on the microphone, and then read the SWR on the tiptop scale of the meter. The SWR should              be below three. The lower, the ameliorate.

What is SWR?

SWR is short for STANDING WAVE RATIO. Information technology is a measure of how well the antenna is performing. Well-nigh problems with the antenna or antenna cable will testify upward during an SWR check.

Please note that the SWR is a measure of antenna operation. A poor SWR is caused by the antenna, the antenna cable, or a poor antenna installation. Poor SWR is not caused by the radio. Since the SWR is a office of the antenna system, changing radios will not affect the SWR.

Why is SWR important?

SWR readings typically have a range of about ane through10. The lower the number, the better the antenna is working. As the SWR climbs, both transmit and receive range will drop. An SWR of 1 is perfect, merely it is non possible to become a perfect reading on all 40 channels. When the antenna is properly adjusted, the SWR is will be highest at the ends of the ring, and lowest in the middle (channel 19).

The SWR reading must never exceed iii, otherwise the transmitter in the CB radio can overheat and eventually neglect. Excessively high SWR can likewise cause other problems such every bit a squealing noise, or can cause interference with other electronic devices in the vehicle. An SWR below 2 is very skilful, and annihilation beneath 1.5 is excellent.

How is the SWR adapted?

The object is to get the SWR the same on channels 1 and forty, AND below 3. This is accomplished by making pocket-sized adjustments to the length of the antenna.

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

  • If the SWR is higher on channel 1, the antenna needs to be longer
  • If the SWR is higher on channel 40, the antenna needs to exist shorter

An adjustment is made to the antenna, so the SWR on channels i and twoscore 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 lot got on channels one and xl.

Virtually 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 past loosening a set spiral and raising or lowering the whip. If you have a heart-loaded antenna (fat section in the middle of the whip), adjust the tiptop whip up and downward. Even if the instructions do not refer to raising and lowering the whip, almost all whip antennas can be adjusted in this fashion.
  • Some models accept a metal collar on the outside of the antenna load (at the base of operations). The neckband is turned to adjust the antenna. This method is non widely used.
  • If you take a fiberglass antenna and there are no visible means of adjustment, it tin be adjusted as 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 whorl upward.
    5. Replace the plastic cap.

It is all-time if you refer to the specific instructions for your antenna or call the antenna manufacturer. For case, some fiberglass antennas take a sleeve which you slide upwards and down to arrange the antenna.

If you cannot get the SWR below 3

The whip is likewise long (steel whip antennas)

If you lot accept pushed the steel whip all the style down and the SWR is still higher on channel 40, then the whip is too long. In this case, it is permissible to shorten the whip by cutting the end. If the whip is painted, scrape the pigment away after cutting so that there is good electric contact with the set screw. DO NOT cut more than than 1/2 inch at a time. Before cutting, read all the fashion through this section.  Your trouble might be an installation trouble, non that the whip is besides long.   Exist careful! If yous cutting too much, you may air current up with an antenna that is now likewise short.

The whip is too short (steel whip antennas)

If you lot have raised the whip as loftier as it can go and the SWR is yet higher on channel 1, please contact the antenna manufacturer.

Very loftier SWR readings

If the needle is going all the way 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-mount installations, the antenna must Not touch on the mounting bracket.  The antenna should screw upward against a plastic insulator. Brand sure that the plastic insulator is in place. If information technology is missing, the SWR will be very loftier. You tin notice replacement insulators at truck stops.
  • On bumper-mount antennas, the most common trouble is the antenna being shorted to basis 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 affair to do is disassemble the antenna mount, then advisedly re-assemble per the installation instructions.
  • The easiest style to diagnose the antenna cable is to simply try a new i. Yous can connect it temporarily and run information technology through the window to the CB. If it solves the problem, and so install the new cable permanently.

If you take an ohm meter then you tin try the post-obit:

  1. Disconnect the antenna cablevision from the radio and measure between the center usher and the connector trounce. There should be NO continuity (you should not get a reading).
  2. If you lot do get a reading, then disconnect the cable from the antenna and repeat the test.
  3. If you still get a reading, then the cable is bad. If you no longer get a reading, then the mountain is installed incorrectly.

The SWR is a little over 3 on all channels

  • Mirror-mount installations must have proficient electric contact with the frame of the vehicle. Effort connecting a #12 ground wire from the antenna subclass to the door swivel.
  • Mounting the antenna to an aluminum surface (tool box, etc.) may not provide a good ground. This is because aluminum is not a good usher. A grounding problem can likewise occur if mounting to a luggage rack. Try running a #12 basis wire to the antenna bracket. If the SWR is nevertheless high, endeavour relocating the antenna.

Wrong type of antenna

It is besides possible that you are not using the right kind of antenna. Most CB antennas must be mounted to a metal surface ("ground aeroplane") in club to operate properly. The metallic body of the vehicle serves this purpose. On fiberglass or plastic body vehicles, a "no-ground-airplane" antenna is needed. This blazon of antenna is specially designed to operate without a metal surface.