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5/8 Wavelength Antenna Formula:
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The 5/8 wavelength antenna is a popular vertical antenna design that offers improved performance over quarter-wave antennas. It provides a lower radiation angle and higher gain, making it ideal for long-distance communications.
The calculator uses the 5/8 wavelength formula:
Where:
Explanation: The formula calculates the optimal length for a 5/8 wavelength antenna based on the operating frequency and the speed of electromagnetic waves.
Details: Accurate antenna length calculation is crucial for optimal signal transmission and reception. Proper length ensures maximum efficiency, impedance matching, and desired radiation pattern.
Tips: Enter frequency in Hz (e.g., 146000000 for 146 MHz). The speed of light is pre-set to 300,000,000 m/s but can be adjusted if needed. All values must be positive.
Q1: Why use a 5/8 wavelength antenna instead of 1/4 wave?
A: 5/8 wavelength antennas provide approximately 3 dB gain over quarter-wave antennas and have a lower radiation angle for better long-distance performance.
Q2: What frequencies is this calculator suitable for?
A: This calculator works for any radio frequency from HF to microwave bands, including amateur radio, commercial, and military frequencies.
Q3: Does the antenna require a ground plane?
A: Yes, 5/8 wavelength vertical antennas typically require a ground plane or radial system for proper operation and impedance matching.
Q4: How does antenna material affect the calculation?
A: The calculation assumes ideal conditions. In practice, a velocity factor (typically 0.95-0.97) should be applied for physical antennas due to material properties.
Q5: Can this calculator be used for dipole antennas?
A: No, this calculator is specifically for 5/8 wavelength vertical antennas. Dipole calculations use different formulas.