For those interested in building their own antennas, having the right tools and information is essential. HamAntCal Version 3.5 (Ham Antenna Calculator) is a valuable app that provides a simple and intuitive way to calculate the starting length for constructing your antennas in feet/inches or metric. In this blog post, we will explore the benefits of using HamAntCal, step-by-step instructions on how to use it, frequently asked questions, and conclusion.
HamAntCal has a variety of benefits, including the ability to work in both feet/inches and metric systems. Its easy-to-use and intuitive interface make it simple to calculate starting lengths for building your antennas. The app can calculate the starting length for “Dipoles,” “Verticals,” and “Inverted Vee” antennas. There is also a page for calculating 1/8, 1/4, 1/2, 5/8, and “Full Wave” length.
One of the standout features of HamAntCal is its ability to work with “Inverted Vee” antennas. The developer encountered different and conflicting information for calculating the length of an “Inverted Vee” antenna. To test this, the developer calculated for a “Dipole” using the “Dipole” calculator.
Then they put together a “Dipole” with a support for the center insulator as well as the ends and measured the resonant frequency with an antenna analyzer. As the ends were lowered towards 45 degrees from horizontal, the resonant frequency increased. This means that the length of the “Inverted Vee” would need to be increased to stay resonant at the same frequency as the dipole.
The “Inverted Vee” calculator in the app has a slider that starts up with an angle of 45 degrees and can be adjusted down to 20 degrees continuously re-calculating as it is moved. This corresponds to about 4.5 to 2 percent added to the length of the “Inverted Vee.”
When using HamAntCal, it is essential to keep in mind that no antenna calculator can give exact results in every case. Many factors can affect the resonant frequency of an antenna, including the wire used, height above ground, ground type, and nearby objects. It’s always a good practice to add a little extra wire and then trim up to the desired frequency.
Q: What frequencies can the calculator handle?
A: The calculator can handle frequencies from 30 Khz to 500Mhz for the “Dipole,” “Vertical,” and “Length” calculators. The maximum for the “Inverted Vee” calculator is 60MHz.
Q: Will the calculator provide exact measurements?
A: No, the calculator does not give exact measurements, and the results will need to be trimmed using an antenna analyzer or SWR meter to the exact frequency after installation.
Q: Is it necessary to leave extra wire on each section for trimming and wrapping around the insulators?
A: Yes, it is important to leave some extra wire on each section for trimming and wrapping around the insulators.
Overall, the HamAntCal Version 3.5 is a powerful and easy-to-use tool that can help antenna builders get started on their projects. With its updated interface, settings menu, and compatibility with both feet/inches and metric measurements, it offers a great deal of convenience to its users.
However, it’s important to remember that antenna building can be a complex process, and there are many factors that can affect the resonant frequency of an antenna. While HamAntCal can provide a starting point, proper matching methods and equipment should always be used to ensure a safe and effective installation.
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