How to Tune an Antenna

PDF download Download Article
PDF download Download Article

When first setting up a radio or moving a radio to a new, permanent location, its antenna needs to be tuned. Learning how to tune an antenna entails lengthening or shortening the antenna so that, for the radio's specific frequency, it is working as efficiently as possible. In order to tune an antenna, a radio needs to be hooked up to an SWR (standing wave ratio) meter using coaxial cables. This guide will teach you how to test an antenna's efficiency using an SWR meter, and how to tune your antenna accordingly.

Steps

PDF download Download Article
    • For a CB radio, put the radio in the car and the antenna on the body of the vehicle. For a portable radio, move away from any vehicle and stand alone with the radio.
    Advertisement
  7. On a CB radio, tune to Channel 1.
  9. It should be in the form of a ratio, e.g. 2.2:1.
    • Repeat Steps 6-8 for the highest band available, or, on a CB radio, Channel 40.
    • If the SWR reading on the lowest band, or Channel 1, is greater, your antenna is too short. If the SWR reading on the highest band, or Channel 40, is greater, your antenna is too long.
    • For most antennas, this means manually lengthening or shortening the antenna. For a wire antenna, clip off a bit of the end to shorten it (if you have a wire antenna that is already too short, you will need to get a new antenna).
  12. Repeat Steps 7-10, tweaking your antenna gradually until the SWR readings on the lowest and highest bands, or Channel 1 and Channel 40, are identical.
    13. Advertisement

Community Q&A

Search
Add New Question
  • Question
    Can I use an SWR meter for a digital TV antenna?
    Imhungry Imhungry
    Community Answer
    No, there are digital tuning meters for tuning signals, but the cheapest I have seen is about $200 and most are over $1000. For $40 you can buy a converter box and use the built-in tuning meter for aiming your antenna, but it isn't battery powered and portable.
    Thanks! We're glad this was helpful.
    Thank you for your feedback.
    If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission. Support wikiHow
    Yes No
    Not Helpful 3 Helpful 5
  • Question
    How do I find the built in digital antenna on an LG TV?
    Community Answer
    It will be on the back of the TV and will usually be a metal bolt with a white center and hole through, also known as coax. It also may be labeled ANT or Antenna.
    Thanks! We're glad this was helpful.
    Thank you for your feedback.
    If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission. Support wikiHow
    Yes No
    Not Helpful 0 Helpful 1
Ask a Question
200 characters left
Include your email address to get a message when this question is answered.
Submit
      Advertisement

      Video

      Tips

      • Always tune your antenna when it is in its natural position as its SWR readings will change as it moves away and toward different structures. If you are using a home-bound antenna, ignore Step 1 and tune the antenna in place.
        Thanks
        Helpful 4 Not Helpful 1
      • SWR meters gauge the efficiency of your antenna: in other words, what percentage of the energy devoted to the antenna is actually being used to transmit. Although a well-tuned antenna is simply one in which the SWR readings at the lowest and highest ends of the band are identical, you should try for SWR readings of 1.5 or less for optimal efficiency. If you have especially high SWR readings, try adding a transformer mechanism between the radio and the antenna or add a mode choke to the outside of the coaxial cable to prevent energy seepage.
        Thanks
        Helpful 2 Not Helpful 1
      Submit a Tip
      All tip submissions are carefully reviewed before being published
      Name
      Please provide your name and last initial
      Submit
      Thanks for submitting a tip for review!
      Advertisement

      Warnings

      Advertisement

      Things You'll Need

      • Radio
      • Antenna
      • SWR meter
      • Two lengths of coaxial cable


      You Might Also Like

      How to
      Make an FM Antenna
      How to
      Hook Up a TV Antenna
      How to
      Build Antennas
      How to
      Make a Wifi Antenna
      How to
      Calculate Wind Load
      How to
      Use Your Home Wiring as a TV or Radio Antenna
      How to
      Make a HDTV Antenna
      Why Is My Antenna Not Picking Up Channels?
      How to
      Make a TV Antenna with a Coat Hanger
      Create a Cheap Wi-Fi Antenna at Home: DIY Guide
      2 Ways to Repair a Radio Antenna: Aluminum Foil & Soda Can
      How to
      Design a Simple Antenna
      Advertisement

      References

      1. http://www.hamuniverse.com/testingswr.html
      2. http://www.roadtripamerica.com/Equipment/How-to-Tune-a-C-B-Radio-Antenna.htm
      3. http://www.rightchannelradios.com/pages/cb-antenna-tuning-and-swr-explained-pv-c0-58.html

      About This Article

      Thanks to all authors for creating a page that has been read 85,128 times.

      Is this article up to date?

      Advertisement