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

  1. 1
    Go to an open area free from buildings, trees, radio towers, or other structures.
  2. 2
    Put your radio and antenna in the positions in which you will use them.
    • 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.
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  3. 3
    Remove any connections between the antenna and the radio.
  4. 4
    Attach the radio to the transmitter socket on the SWR meter using a coaxial cable.
  5. 5
    Attach the antenna to the antenna socket on the SWR meter using a coaxial cable.
  6. 6
    Set the radio to minimum power and to FM or CW mode.
  7. 7
    Tune to the lowest band available. On a CB radio, tune to Channel 1.
  8. 8
    Transmit from the radio or, on a CB radio, press the talk button.
  9. 9
    Observe and record the SWR reading. 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.
  10. 10
    Determine from the difference between the SWR readings whether your antenna is too short or too long.
    • 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.
  11. 11
    Adjust your antenna accordingly, and very slightly.
    • 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. 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.
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Community Q&A

  • Question
    Can I use an SWR meter for a digital TV antenna?
    Imhungry Imhungry
    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.
  • Question
    How do I find the built in digital antenna on an LG TV?
    Community Answer
    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.
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Warnings

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Things You'll Need

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


About This Article

wikiHow is a “wiki,” similar to Wikipedia, which means that many of our articles are co-written by multiple authors. To create this article, volunteer authors worked to edit and improve it over time. This article has been viewed 72,312 times.
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Co-authors: 7
Updated: November 5, 2020
Views: 72,312
Categories: Antennas
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