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Introduction
In this blog, we will take an in-depth look at a the JPC-12 Portable HF Antenna that offers much more than meets the eye. While this antenna has been extensively reviewed on YouTube, we will explore its basic concept and potential for extended use. By understanding how this antenna works and the modifications that can be made, we can unlock its full potential. So, let's dive in!
The Basics of the Antenna
The JPC-12 Portable HF Antenna is a vertical whip antenna, a type that is commonly used for portable operation due to its compact size. It utilizes telescopic elements, allowing for easy transportation and storage. By changing the length of the antenna, it can cover a range of bands. For example, on the 40m band, some inductance needs to be added. On the 20m band, only a small amount of inductance is required. From 20m up to 10m, the antenna functions as a full-size antenna. Additionally, it covers the 6m band as well.
Kit of Parts
- Loading Coil
- Base Unit with SO239 Antenna Socket
- Telescopic Whip
- Four Lower Whip Sections
- Earth Spike (Support for Base Unit)
The antenna also comes with a lengthened ribbon cable that can be pulled apart to form four radials, which are essential for the operation of a vertical antenna. All these components come in a convenient carry case, making it ideal for portable use.
Coil and Inductance
The coil of this antenna is a wide-spaced winding on a nylon former with a diameter of approximately 4 cm. It features a sliding shorting bar that allows for easy adjustment. The total inductance of the coil is approximately 24 microhenries. The base unit is constructed with a combination of heavy metal and plastic overlay, with a cutout for the SO239 antenna socket.
Testing and Modifications
Now that we have covered the basics of the antenna, let's take a closer look at its performance and explore some potential modifications.
Setting Up the Antenna
Setting up the antenna is a relatively simple process. The base unit is connected to the earth spike, which is inserted into the ground. The lower whip sections are attached to the base unit, followed by the coil and the telescopic whip at the top. Radials are attached to the earth spike, providing the necessary grounding.
Testing the Antenna
The JPC-12 Portable HF Antenna was tested using an SWR meter and a length of coaxial cable. It was found that the antenna resonates at various frequencies depending on the band. On the 40m band, with the inductance added and the antenna fully extended, the SWR was 1.45:1. On the 20m band, with a small amount of inductance, the SWR was approximately 1.5:1. The antenna performed well on the 80m band and covered the 6m and 4m bands effectively.
Modifying the Antenna
One potential modification explored was placing the loading coil at the bottom of the antenna to achieve a wider frequency range. However, it was found that this caused issues with the SWR at certain frequencies. This led to a discussion about the potential negative effects of shorting out the coil. It was suggested that physically shorting out each turn of the coil may be a more effective method. Additionally, the possibility of using the antenna indoors was also explored.
Conclusion
In conclusion, this JPC-12 Portable HF Antenna offers great flexibility and performance. With the ability to cover a wide range of bands and the potential for modifications, it is a versatile option for both portable and indoor use. The antenna's compact size and convenient carry case make it an excellent choice for QRP expeditions. Whether you are an amateur radio operator or a radio enthusiast, this antenna has a lot to offer. So, why not give it a try and unlock its full potential?
Thank you for reading this comprehensive review of the JPC-12 Portable HF Antenna. We appreciate your support and invite you to visit our website for more information. At Waters and Stanton, we are proud to be one of the largest dealers in the UK, offering a wide range of products and exceptional customer service. We look forward to assisting you with all your radio needs. Stay tuned for more exciting content!