In short wave radio communications, proper antenna selection and construction is critical for both transmission and reception of radio signals. The half-wavelength dipole antenna is one of the most versatile and easy ways to construct short wave antennas. You can construct this antenna in just a few minutes from simple items. Have a question? Get an answer from online tech support now!

Things You'll Need

    Antenna wire
    3 x insulators

    Rope or strong string
    2 x connection points

Instructions

1.Determine the required length of the antenna wire using the following formula: 468 ft./Frequency in MHz

For example, if you are constructing an antenna to use at 18MHz, divide 468 by 18 to arrive at 26. The total antenna length will be 26 ft. Each section of the half-wavelength dipole will be 13 ft.

2.Determine the height at which you will place the antenna above ground using the following formula: 246 ft./Frequency in MHz

For example, to construct an antenna for 18MHz, divide 246 by 18 to arrive at a height of 13.6 ft. Round the height to the nearest foot for simplification.

3.Determine the antenna's orientation. The maximum gain for a dipole antenna is at right angles to the antenna. In other words, if the station to which you want to transmit is located due north of your location, the antenna needs to run due east-west. The antenna will transmit equally in both directions, so the antenna will also transmit due south. Placing the antenna in a location where there is a reflective surface opposite the transmission direction will add power to the antenna.

4.Cut the lengths of antenna wire to the proper length specified in step 1. Connect the two lengths of wire together using an insulator. This can be a commercial insulator of the type you can purchase at an electronics store, or it can be a field expedient insulator. You can use anything that doesn't conduct electricity as an insulator. Some examples are glass, plastic and rubber.

5.Attach insulators to each end of the antenna.

6.Connect the transmission line to the antenna. This is the line that will lead from the antenna to your radio. Connect a separate wire to each of the two sides of the antenna, close to where they connect via the insulator. If you are using insulated wire, strip off some of the insulation so the transmission line makes metal to metal contact with the antenna. Ensure that the transmission line is long enough to reach your radio.

7.Select your antenna's connection points. You can use anything that will allow you to raise the antenna to the proper height and orient it in the proper direction. Examples are trees, buildings and poles. A good solution is to use one fixed point, and one movable pole that you can relocate. This allows you to change the antenna's orientation easily.

8.Attach the antenna to the connection points using rope or string, making sure the antenna is at the proper height, and is oriented in the right direction.

9.Connect the transmission line to the radio. One wire will connect to the center portion of the radio's antenna plug, and the other wire will connect to the outer portion of the plug.

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How to Make a Shortwave Dipole Antenna

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